Creating a New Bathroom

Home | Wiring | Plumbing | Kitchen/Bath

Whether you are adding a new bathroom or modernizing an old one, the details of the job will depend on a number of factors—among others, the structure of your house, the size of your budget, and your own tastes. The following discussion explains the skills you are likely to need in any bathroom renovation, including planning, demolition, carpentry, laying new pipes, and installing fixtures.

Planning the Job

  • An Array of Fixtures
  • Basic Bathroom Layouts

Clearing the Way for a Major Renovation

  • Removing Washbasins
  • Disconnecting a Toilet
  • Taking Out a Tub
  • Tearing Down an Old Wall

Framing for New Pipes

  • Adapting an Old Wall for Plumbing
  • A New Wall Designed for Piping
  • Supports for Pipe and Fixtures
  • Safe Passage through Studs and Joists

Getting Rid of Wastes: The DWV System

  • Routing Drains to the Stack
  • A Drain Line for Each Fixture
  • Adding the Vent Stacks
  • Linking Up with the Main Stack
  • A New Vent Stack through the Roof
  • Testing the New Drains All at Once

Getting Water to the Fixtures: The Supply System

  • Tapping into Copper Supply Lines
  • Dealing with Galvanized Steel Water Pipes
  • Lines for Every Fixture

Installing a Tub or Shower

  • Easing a Bathtub into Position
  • Setting Up a Tub-and-Wall Unit
  • Assembling a Shower Stall

Completing the Room

Hooking Up a Toilet


Breaking up tiles to remove a bathtub


Planning the Job

Remodeling a bathroom or adding a new one is a complex job that requires thorough planning. You must make basic decisions about the sizes and styles of fixtures and appliances, what floor and wall coverings to install, and how to provide or modify lighting, heating, and ventilation.

--Preliminary Considerations: Unless you plan simply to remove the old fixtures and replace them with new ones, you will need to put in additional plumbing lines. The location of existing pipes and the distance they can be extended will often dictate the lay out of a remodeled bathroom and may also limit your choice of locations for a new one. Especially critical is the location of the main stack for the house, which vents out of the roof and extends down to the house drain.

The additional fixtures required for a new bathroom can reduce water flow through the supply lines if your plumbing system already has low pressure or constricted pipes. Make solutions to such problems your first order of business.

To expand a bathroom, you will need to demolish old walls and you might have to build new ones. Avoid disturbing any bearing walls; you can recognize one by following the guidelines.

--A Quartet of Codes: Learn the code requirements in your area as soon as possible in the planning stage to avoid wasted time and money. Four different codes may affect work on a bathroom: plumbing; electrical; mechanical, for heating and cooling systems; and building, for any structural changes to bearing walls, including exterior ones. Permits and specific plans are often required for each code. Your project will probably have to pass a rough- in inspection for each permit once the basic work is done, and a final inspection at the end of the job.

--Pipe and Fixtures: For extending supply lines and drain lines, choose materials that are easy to work with. You don’t need to match new pipe to old; adapters are avail able that will make the transition. For drains and vents, use polyvinylchloride (PVC) plastic if local codes permit; most do. PVC is light weight, readily cut with a saw, and easily assembled with special- purpose cement. Hot- and cold- water pipes may be any of several materials; in the examples shown, the supply pipes are rigid copper, which remains a common choice for its durability.

Select your fixtures, usually including a toilet, washbasin, and tub or shower, early in the project so that you can take their dimensions and framing requirements into ac count. A sampling of basic options appears.

--Hiding Waste Lines: Drainpipes are large—the smallest drain from a bathroom fixture has a 1.5-inch inside diameter—and concealing them can be tricky If the new bath room is above a crawlspace or an unfinished basement, branch drain- pipes can be run between or beneath the floor joists. For a new installation above a finished part of the house, you must cut away some of the ceiling below to install the pipes, and you may also have to drill through the joists to accommodate them.

Vertical drainpipes and vent pipes are usually concealed inside a structure called a wet wall that is framed with 2-by-6 studs instead of the usual 2-by-4s in order to accommodate the pipes. Alternatively, supply lines and drain lines can be run alongside an existing wall and concealed—within cabinets, bookcases, closets, or specially made paneling.

===== Tips on Positioning Fixtures ====

--In a room with an existing stack , or in which a new stack must be located in a particular area, plan the placement of the toilet first—local codes normally dictate a maximum distance between the toilet and the stack.

--Because a full bathtub is very heavy, the best location for the tub is along a wall or in a corner, where it can be sup ported by proper framing. Provide extra floor bracing as shown.

--Position the foot of the tub against a wall that can be opened from the other side for plumbing repairs; whirlpool tubs must be installed so that there is also access to the motor.

--If possible, allow space around the washbasin for towel racks, hooks, and cabinets or shelves for storage.

--In a windowed bathroom, try to position the basin to take advantage of natural light for shaving and applying makeup.

========== ======= ======


Paths for new pipes.


In this simplified diagram, the plumbing for a first-floor kitchen and a second-floor bathroom, both installed when the house was built, appears in dark colors. Pipes for a powder room (1) added next to the kitchen and for a second upstairs bathroom (2) have lighter tints.

The original plumbing core consists of pipes originating in the basement. Parallel supply pipes carry cold water (blue) from the service main and hot water (red) from the water heater.

Drainpipes (gray) carry wastewater from the fixtures into the soil stack— the portion of the stack that leads down from the highest waste outlet to the house drain. Each fixture has a drain trap that prevents sewer gases from entering the house. Vent pipes (purple) linked to the vent portion of the stack exhaust waste gases through the roof.

Both the new powder room and the new second-floor bath illustrate ways new plumbing can be grafted to an existing system. The powder room contains a toilet and basin. It’s close enough to the original plumbing core to be tied directly to it. The new drain runs across the unfinished basement ceiling below, and new vent pipes run parallel to the stack before connecting with it on the second floor. The supply lines are extensions of nearby hot and cold vertical lines, called risers. The full-size upstairs bathroom requires a long run of piping across a first-floor ceiling. Fixtures are vented to a pipe that crosses the attic to connect with the existing vent stack.


-- Standard tub. This 60-inch by 30-inch tub is commonly available in fiberglass, cast iron, or steel. It may have one, two, or three skirted sides, depending on how many walls the tub will abut. You can also buy this style tub with all four sides unskirted and sink it into a floor or raised platform.

-- Whirlpool tub. Equipped with a pump to circulate bathwater through nozzles in the sides, a whirlpool tub requires its own electric circuit. Modest units like this one resemble a standard bathtub and range up to 7 feet in length. A tub of this size usually fits through halls and doorways en route to the bathroom but may feel cramped to some.

-- Oversize whirlpool tub. A unit wider than a standard tub offers luxurious comfort. However, it won’t pass through a standard door or ha so it’s often practical only for a new bathroom near a sliding-glass door in an exterior wall. A large tub also may require extra floor reinforcement and two electrical circuits—one for the pump motor, another for a heater.

-- Multipiece tub surround. Sold as a kit of separate panels, a tub surround like the one above can be carried through any doorway, then assembled as shown. To prevent leaks, you must carefully maintain joints with caulk.

-- A seamless tub-and-wall unit. Like a large whirlpool tub, a one-piece tub enclosure cannot fit through a standard hail or doorway, making it impractical for some renovations. This lightweight unit offers an advantage over surrounds built of separate panels: the corners remain watertight.

-- One-piece shower stall. Some enclosures for showers come as a single unit like the one above; others must be assembled from panels. Select a shower that you can maneuver into the new bathroom, and allow room in your layout so the shower door can swing outward.



-- Two-piece toilet. The traditional toilet consists of two major components, a tank and a bowl, which may be separated for certain re pairs. Round bowls like the one shown here are standard, but elongated bowls are also available, at a higher price.

-- One-piece toilet. A compact alternative to the two-piece version, this toilet frees wall space for shelves or cabinets. Because of their lower profile, one-piece toilets don’t rely on gravity alone for flushing; in stead, a special mechanism pressurizes the water that clears the bowl.

-- Wall-hung basin. Requiring no cabinetry for support, a wall-hung basin occupies less space than many other kinds of sinks and so is well suited to small bathrooms. As its name suggests, this type of basin simply hangs from a mounting bracket attached securely to the wall.

-- Pedestal basin. Most pedestal basins are supported by framing in the wall. The base, which is largely decorative, conceals the drain assembly while still leaving ample free space underneath.

-- Integral countertop basin. Designed to be mounted onto a vanity, this type of basin is part of a small molded counter with a backsplash. The space between the basin and the backsplash may be ordered predrilled for any of the standard faucets shown earlier [Section 5: New Fittings for Basins and Tubs].




-- Standard clearances. Most building codes specify minimum clearances to the front and sides of each bathroom fixture. The figures noted at left are common, but check your local code for specifics in your area. Code requirements set minimum clearances; for comfort, allow for more space if possible. Under most codes, fixtures must have a minimum of 21 inches of free space in front. Codes also commonly mandate 15 inches to each side of a toilet’s centerline. A bathroom door is normally required to be at least 24 inches wide and to open through an arc of at least 90 degrees; see Section 6--UPDATING YOUR BATHROOM for the dimensions needed for wheelchair access.

Rough-in dimensions.


After selecting fixtures and planning their placement, establish locations for pipes to enter the room. If you are using an old wall, mark the wall surface; otherwise, mark the framing members of the new wall. The measurements shown here along a single wall are typical for some common fixtures.


A one-wall plumbing pattern.


The simplest plan for a bath room consolidates the plumbing along one wall, reducing the amount of cut ting into the house structure and the amount of pipe in stalled. This arrangement may be the only choice for a small bathroom like that at left, which has rough-in dimensions identical to those in the illustration shown for “Rough-in dimensions”.

Plumbing in two walls.


Extending supply pipes and drainpipes to two adjoining walls provides more room around the basin than a one-wall room. (Three-wall plumbing patterns are less common, since they offer few advantages.) A bathroom with plumbing in two walls generally requires more cutting of studs and joists to accommodate the pipes. To minimize such work or to bridge a door, try to run the supply pipes underneath or between the joists directly below.



Clearing the Way for a Major Renovation

Remodeling a bathroom usually requires that some or all of the old fixtures be removed. Enlarging a bathroom or creating space for a new one may also mean tearing down one or more walls.

--Taking Out Fixtures: Always begin by cutting of f water to the fix ture, usually at the nearby shutoff valves in the supply lines. In the absence of such valves—or if they are stuck open— you may have to turn off the water supply to the en tire house. Removing most fixtures consists mainly of undoing nuts and bolts. A bathtub, however, can present a consider able challenge. Disposing of a plastic, fiberglass, or steel tub may be made easier with a reciprocating saw, which is available from tool-rental stores.

If you plan to reinstall your washbasin, bathtub, or toilet, handle the fixtures carefully; they are fragile and easily damaged when dropped or bumped.

--Breaking Down an Interior Wall: If you plan to expand a bath room, don’t disturb a bearing wall. Before starting demolition on a nonbearing wall, look for evidence of utilities—heating, air conditioning, or electricity—that may be housed within. Vents signal the presence of ducts, which can often be rerouted from the wall to the floor. Electrical switches or outlets indicate wiring that must be removed or relocated.

Supply pipes passing through a wall on the way to plumbing fixtures elsewhere may not be evident. If you find them during demolition, you will have to reroute them. Think twice about moving a plumbing wall. You can often redirect small branch drains, but large drains and stacks ordinarily must be left in place and concealed.


  • Adjustable wrench
  • Socket wrench
  • Putty knife
  • Large groove-joint pliers
  • Small pliers
  • Screwdriver
  • Pry bars
  • Cold chisel
  • Dry-wall saw
  • Reciprocating saw
  • Sledgehammer
  • 4-pound maul
  • Tin snips
  • Chalk line
  • Utility knife
  • 6-inch and 12-inch dry-wall knives
  • Bucket
  • Sponge


  • Pipe caps and plugs
  • Picture-hanging wire
  • Rags
  • Fiberglass mesh tape
  • Joint compound

====Capping Pipes====

Cover the open ends of all pipes to keep out construction debris and, in the case of drains, to prevent sewer gas from entering the house. Plug toilet flanges with rags, and cap the other drains and the supply lines. If a pipe is threaded, screw on a cap or insert a plug of the same material. Cement a plastic cap onto, unthreaded plastic pipes (the capped end must be sawed off to reopen the pipe); unthreaded copper pipes require a soldered copper cap.



===== ====

SAFETY TIPS---Demolition creates dust, flying splinters of wood and metal, and other potentially dangerous debris. Wear goggles, a dust mask, and leather work gloves. Long sleeves, sturdy long pants, and boots are also in order. A cap will keep the mess out of your hair.

=== ======


1. Freeing the fixture.


• Disconnect the supply lines, the pop-up linkage, and the trap. Remove a wall-hung or pedestal basin as shown. Lift out a basin with a lip that rests on a vanity top. For a basin that is part of a vanity top, unscrew and remove the top.

• To detach a sink secured by a metal rim (above), lay a 2-by-4 across the basin. Bend a piece of picture-hanging wire over the 2-by-4, passing both ends through the drain hole. Twist the ends together below the tailpiece and insert a wood block between the doubled wire. Turn the block to draw it tightly against the tailpiece.

• Unfasten the lag bolts (inset) and hold-down clips and turn the block in the opposite direction to lower the basin.

2. Removing faucets.

• Place the basin facedown on the floor so that it’s resting on the faucet handle. Pad the basin carefully if you intend to reuse it.

• With an adjustable wrench, unscrew the lock nuts from the faucet shanks. Lift off the washers.

• Turn the basin face up and tap the faucet to break the seal of plumber’s putty, if necessary, then lift out the faucet.


1. Disconnecting tank and bowl.


To remove a two-piece toilet, detach the tank, then unbolt and lift up the bowl. Take out a one-piece model as you would a bowl.

• Close the shutoff valve, flush the toilet, then bail and sponge the remaining water from the tank and bowl. De tach the supply tube as you would a sink line.

• For a bowl-mounted tank, unscrew the nuts under the bowl’s rim with a socket wrench. Use a screw driver, if necessary, to keep the boltheads from turning.

• If the tank is hung on the wall, remove the L-shaped pipe connecting it to the bowl by loosening the slip nuts at each end. Then take out the screws or bolts that hold the tank to the wall.

• For any type of toilet, pry the caps from the closet bolts and remove the nuts.

• Rock the bowl to break the seal between toilet and flange. Lift the bowl free.


2. Scraping the toilet flange.


• Stuff an old rag into the toilet drain to block sewer gases.

• Slip the bolts out of the slots in the toilet flange and scrape away the wax gasket with a putty knife.

• inspect the flange; if it’s cracked, plan to replace it before seating the new toilet.


1. Disconnecting the tub.


• Remove the access panel in the wall behind the tub’s plumbing fixtures. If there is no panel, cut a 1.5-inch-square hole, starting at floor level and taking care not to damage pipes in the wall.

• With large groove-joint pliers, loosen the slip nut connecting the waste and overflow pipes to the drain pipe outlet.

• Returning to the tub, remove the overflow plate and lift linkage, and take out the strainer by re moving the strainer screw. If there is no screw, raise part of the edge of the strainer with an old screwdriver, then tap the screwdriver counterclockwise.

• Insert the handles of small pliers in to the crosspiece. Use a pry bar along with the pliers to unscrew the cross- piece (inset).

Remove the spout, faucets, and shower arm, following the procedures.


2. Freeing tub flanges.


• Remove a foot-high section of finished wall above the tub. For a tile wall, such as the one shown here, use a cold chisel and hammer to chip away the tile. For molded panels, re move the entire surround.

• Cut the waterproof wallboard behind the tile with a dry-wall saw; demolish cement board or plaster with a hammer and chisel.

• Remove screws or nails anchoring the tub flange to the studs.

3. Removing the tub.


• If space allows, and you wish to save the tub, carry it out whole. Be sure to recruit enough helpers for the job. Even a lightweight fiberglass tub is hard to handle in a tight place.

• To demolish an unwanted tub for disposal, first examine an exposed edge to determine whether it’s made of plastic, fiberglass, steel, or cast iron. Confirm your assessment by rapping the tub with your knuckles. Plastic or fiberglass tubs sound hollow. A steel tub emits a metallic ring. Cast-iron tubs respond with a dull tone.

• Cut up a fiberglass, a plastic, or a steel tub with a reciprocating saw (above, left).

• Break up a cast-iron tub with a sledgehammer (above, right). Wear safety goggles, long sleeves, and work gloves—and cover the tub with a drop cloth to trap flying shards.




1. Tearing away the wall surface.

• Turn off electricity to any cables— and water to any supply pipes—before entering the wall.

• With a 4-pound maul, smash numerous large holes in the wall between studs. The holes prevent the surface from peeling off in one piece—a potential cause of injury.

• In a plaster wall, cut metal lath from the holes with tin snips; wood lath can be cut with a reciprocating saw.

• To strip the wall, grip the edges of the holes with both hands and pull outward sharply. Doing so will break any wall material and will even tear metal lath.

• Use a pry bar to lever remaining bits of wallboard from the studs to which they are nailed.

• Remove any electrical cables, plumbing lines, or heating ducts that run through the wall, and reroute them if necessary.

!! CAUTION !! ---If the wall you plan to demolish was built before 1978, check the surface for lead with a kit from a hardware store and have a piece tested for asbestos by your local government or a laboratory. If either substance is present, hire a contractor trained in dealing with hazardous materials to take out the wall.

2. Removing the second wall surface.


• Loosen the other surface of the wall with a maul. For wallboard, hammer next to studs; once freed, entire wall- board panels can be pushed free of the studs into the next room. For plaster, knock all the material from the wall, then pry the lath from the studs.

• Saw all but the end studs in half and pull them free.

3. Dislodging the end studs and soleplate.

• Sever both end studs with a reciprocating saw and cold chisel to create a 2-inch gap in each board.

• Insert a pry bar into the gap and remove one stud section. A block of wood can serve as a fulcrum to lever off the second piece.

• Remove the soleplate in the same way.


4. Removing the top plate.


• For joists parallel to the top plate, use a stud finder and a chalk line to mark the centers of the joists on either side of the plate. Score each line deeply with a utility knife.

• Use a hammer to break up the wallboard or plaster and lath between the ceiling cuts, then clean up the edges of the opening with the utility knife.

• Pry the top plate loose from the nailer blocks to which it’s attached.

• For joists that cross the top plate, score the ceiling 12 inches to each side of the plate and pry both dry wall and top plate loose.

5. Patching the gaps.

• Cut dry wall to fit the ceiling gap. For an opening longer than 8 feet, trim sections of wallboard to end midway across either the joists or the nailer blocks.

• Where joists cross the gap, screw the patch to each one. Where joists parallel the gap (above), drive the screws into the nailer blocks between the joists and into the edges of the joists, angling the screws slightly outward from the patch to anchor them solidly.

Fill the gap in the flooring left by the soleplate with a strip of plywood of the same thickness.

6. Finishing the ceiling patch.


• Apply a strip of self-adhesive, fiber glass mesh tape with a 6-inch dry-wall knife (above, far left).

• Spread one coat of joint compound, holding the knife at a low angle (above left).

• Wait 24 hours to allow the compound to dry, then scrape off any ridges with the knife and apply a second coat of compound, diluting it for a smooth finish.

• After the second coat has dried, smooth the seam with a moist sponge. With a 12-inch dry-wall knife held at a steep angle, apply a final skim coat of compound diluted with water.



Framing for New Pipes

Before running new pipes, you must construct framing to support them—not only in the bathroom walls and floor, but along the course the pipes will follow through the house. Framing is also needed for most fixtures.

When attaching new framing, substitute 3 dry wall screws for nails of the same length where hammering could jar a nearby finished wall or floor.

Thick Walls for Pipes: Drain and vent pipes in a bath room range from 1 inches for a washbasin drain to 4 inches for a toilet; the small basin drain is most likely to be routed through a wall. For adequate support and concealment, an old wall of 2-by-4 studs can be made thicker with furring strips (below). Or build a new wall for the plumbing, often called a wet wall.

--Supporting Fixtures: Frame for fixtures as shown. A washbasin set in a vanity requires no additional framing, but wall-hung and pedestal models are usually supported by a crosspiece between two studs. Tubs need framing in the floor and wall, as well as crosspieces for the faucet and shower assemblies.

--Running Pipes: Route the bathroom’s supply pipes and drainpipes horizontally toward the vertical plumbing core of the house, either through the floor joists or—preferably—just below the joists. Follow local codes for joists, which are part of the basic structure of your house. Never run a long section of drainpipe through joists, since the required pitch of inch per foot cannot be accommodated.

Drill holes for pipes, in studs or joists, inch larger than the pipe. Bore holes inch larger than the pipe if you must insert it at an angle, a technique permitted by the flexibility of copper and PVC. To reduce noise, you may opt for foam pipe insulation; this requires still bigger holes. In no case, however, should holes be larger than 60 percent of the depth of a stud or joist.


Fitting drain and supply lines.


• Remove the baseboard.

• If you plan to install a stack, remove wallboard or plaster between the studs to each side. Drill a pilot hole through the soleplate and floor at the center of the stack. Expand the hole to full size with a hole saw; if necessary, drill first from above and then from below, tapping out any remaining wood with a hammer. With a spade bit, drill holes 4 to 6 inches apart for supply pipes.

• For studs that are not crossed by drains or vents, cut 2-by-2 furring strips the full length of the studs.

• Where studs will be crossed by washbasin drainpipes or vent pipes, mark the location of the pipe run on the wall. Cut 2-by-2 furring strips to fit above and below the pipe. Remove the wall surface as needed, and notch the original studs to recess pipes that exceed 1 inches in diameter.

• With an electric drill and a screwdriver bit, drive 3.5-inch dry-wall screws through the furring strips into the studs.

• Drill supply pipe holes in the furring strips, next to the old wall surface.

After drainpipes and vent pipes are in place, anchor them with drainpipe straps and shield them with metal pipe-protector plates, - inch thick and long enough to extend past each supply pipe.




  • Electric drill
  • Hole saw, spade, and screwdriver bits
  • Electronic stud finder
  • Chalk line
  • Plumb bob
  • Utility knife
  • Tape measure
  • Carpenter’s square
  • Level
  • Ball-peen hammer
  • Small pry bar


  • 2-by-2 furring strips
  • 1 -by-2s, 2-by-4s, and 2-by-6s
  • Larger framing lumber as needed
  • 3.5-inch nails
  • 3.5-inch dry-wall screws
  • Hollow-wall anchors
  • Cedar shims
  • Joist hangers

===SAFETY TIPS---Constructing walls and framing with nails produces loud banging and may cause nails and wood chips to fly. Use earplugs and goggles for ear and eye protection.


1. Planning the wall location.


• With an electronic stud finder, locate several ceiling joists.

• If the joists run perpendicular to the planned wall (above, left), mark for a 2-by-6 top plate on the ceiling, snap ping a chalk line along each edge. With a plumb bob, transfer the marks to the floor, then snap a chalk line along each edge of the soleplate.

• For joists parallel to the wall (above, right), find the nearest joist. Snap chalk lines for the top plate so that it extends 4 inches into the new bathroom. Transfer the top plate location to the floor with a plumb bob, and mark the edges of the soleplate with a chalk line.

To place a wall between two joists (inset), open the ceiling between them and use joist hangers to install nailer blocks at 24-inch intervals. (No framing is needed under the wall, if the floor is at least 1 1/8 inches thick.)


2. Marking the top plate and soleplate.


• From 2-by-6 framing lumber, cut a soleplate and top plate the length of the new wall, and temporarily face-nail the boards together.

• Beginning at one end, mark the plates every 16 inches to indicate stud locations (left). Plan for studs at both ends of the wall, making the stud space at one end narrower than 16 inches if necessary. If you plan to place the drain of a tub or shower against the wall, adjust two stud positions to center the drain between them.

3. Assembling the frame.


In a tight space, you might have to nail the soleplate and the top plate to the floor and the ceiling, then toenail the studs to both of them. An easier method is to assemble the frame as shown here and raise it into position.

• Every 2 feet along a soleplate line, measure the distance from the ceiling to the floor. Cut 2-by-6 studs 3.25 inches shorter than the smallest measurement. Doing so assures a frame short enough to clear the ceiling when being raised from the floor.

• Fasten the studs to the top plate and soleplate with 3.5-inch nails, making sure that any crowns face up (inset).


4. Cutting holes for vertical pipes.

• Before raising the new wall, mark the floor with the centers of holes for vertical pipes. If possible, keep holes at least 1.5 inches inside the planned wall; otherwise, you must later install pipe-protector plates.

• Draw reference lines from the centers across the chalked line marking one edge of the soleplate so that the chalked line divides each reference line into two equal parts (inset).

• Drill pilot holes in the floor. Use a hole saw for the stack, finishing the hole from below if necessary (left). Drill the supply pipe holes with appropriately sized spade bits.

5. Installing the wall frame.


• With a helper, raise the wall. If it lines up with studs inside the existing walls, attach the end studs with 3.5-inch dry-wall screws at 24-inch intervals (above); otherwise secure the end studs with hollow-wall anchors.

• Push pairs of tapered cedar shims between the top plate and ceiling, one from each side. Put shims under perpendicular joists or nailer blocks; otherwise, 16 inches apart. Drive screws through the top plate and shims, into the framing. Score protruding shims with a utility knife; snap them off.

• If the joists run perpendicular to the soleplate, screw it to each joist.

• When a floor joist runs along the wall, screw the soleplate to it at 16-inch intervals, avoiding where the pipes will go. Between joists, screw the soleplate to the floor.

• Locate the reference lines for the pipe holes. Measure each line and extend it inward by the same amount, then drill through the soleplate (inset) to match the holes in the floor.



Framing for a closet bend.


• For a waste pipe that runs perpendicular to joists, you must cut a gap in the intervening joist. In the room below, remove a strip of ceiling, exposing the joist that blocks the planned path of the waste pipe and one joist to either side of it.

• Temporarily brace the middle joist with two vertical studs outside the opening, then cut out an 18-inch section of the center joist.

• From joist lumber, cut four boards to fit between the two uncut joists.

• Face-nail the boards together to make two doubled headers (above), and nail double joist hangers to both ends of each. Nail the joist hangers to the joists, then secure the headers to the cut joist with single joist hangers. Remove the temporary support studs.

• Support the waste pipe at the correct slope with a 1 -by-2 support between the headers (inset).

The only framing necessary for a toilet waste pipe that parallels the floor joists is the 1 -by-2 support.

Support for a washbasin.


• From a 2-by-6, cut a crosspiece to fit between the studs on either side of your washbasin.

• Level the crosspiece at the height specified by the basin manufacturer, and secure it with two 3.5-inch nails or screws through the studs.

• Attach the basin mounting bracket to the crosspiece after the wall is closed and finished.

CAUTION---Procedures below require cutting joists. If your house has wood I-beam or truss joists, hire a structural engineer for those parts of the job.

== ==TRICKS of the TRADE== ==

--Hammering Nails in Close Quarters--


Framing for a fixture or pipe in a restricted space, as with the closet bend at left, can be extremely difficult.

One solution is to start the nail, then place the end of a 2-foot pry bar against the nailhead. To drive the nail strike farther down on the pry bar with the flat face of a framing hammer (the hardened steel of a pry bar may chip an ordinary trim hammer).

== ==


Underpinnings for a bathtub.


• In the floor, cut a 12-inch-square hole, one edge at the soleplate and centered side to side on the spot to be occupied by the tub drain; the tub overflow pipe and drainpipe will later connect to the drain system in this area.

• If the opening exposes a joist and you cannot adjust the planned position of the tub, install headers as shown here. To do so, follow the procedure for a closet bend.

Bath and shower faucet framing.


• Mark the heights of the tub faucet assembly and the shower arm on the studs behind the drain end, or “head,” of the tub.

• Cut a 2-by-6 faucet support to lit between the studs and nail it in place, recessing it into the wall according to the specification sheet provided by the faucet manufacturer.

• Attach a 2-by-4 support the same way for the supply pipe that will attach to the shower arm.


Supporting the tub.


• To provide the edge support needed by most bathtubs installed next to a wall, remove any wall surface to expose the studs, then cut a 2-by-4 support to extend from the planned location for the foot of the tub to the head of the tub.

• Level the support and nail it to studs at the height specified by the tub manufacturer. Use a vertical nailer block to attach the support at the head of the tub, as shown at left. If necessary, to anchor the other end of the support, toenail an additional stud at the end of the 2-by-4.


Pipes in a wet wall.


To run pipe inside a wall built for plumbing, drill holes through the studs with spade bits for the supply pipes and a hole saw for drainpipe or vent pipe. Align the holes for each pipe precisely, and try to keep them at least 1 inches from the edges of the studs; otherwise use pipe-protector plates. The slope of supply pipes is unimportant, but drainpipes must slant downward toward the stack, 0.25 inch per foot. SUPPLY PIPES; DRAINPIPE

=== TRICKS of the TRADE ===

Drilling in Close Quarters


A drill and its bit may be more than a foot long—potentially awkward for working in the 14.5-inch space between joists and studs. A right-angle drill offers a solution. Available at tool-rental stores, this tool also comes as an attachment for many standard drills and easily fits between framing members.

== ==



-- In standard joists. Whenever possible, hang pipes under floor joists rather than cutting holes in the joists. If you must run pipes through joists, drill the holes to allow at least 2 inches between the hole and the top and bottom of the joist.

-- In I-beams. Joists like those at left, consisting of a plywood web between two 2-by-4s, have become common in home construction. Don’t cut the 2-by-4s, but cut pipe holes freely through the thin center piece; some I-beams come with knockout holes for the purpose.

-- In truss joists. Built like a bridge girder from 2-by-4s, a truss joist requires no hole drilling for pipes; when the time comes, pass them through the joists and suspend them with metal pipe hangers nailed to the cross members as shown at left. To minimize sound transferred in this particularly noisy arrangement from pipe hangers to joists, plan to fit foam pipe insulation around the pipe, as shown at left.

-- Pipes in a wet wall. To run pipe inside a wall built for plumbing, drill holes through the studs with spade bits for the supply pipes and a hole saw for drainpipe or vent pipe. Align the holes for each pipe precisely, and try to keep them at least 1.5 inches from the edges of the studs; otherwise use pipe-protector plates. The slope of supply pipes is unimportant, but drainpipes must slant downward toward the stack, inch per foot.



Getting Rid of Wastes: The DWV System

Drainpipes and vent pipes, collectively called the drain-waste-vent (DWV) system, are the most complicated part of a plumbing network. Work will go more smoothly if you install the DWV system before the supply lines.

--Where to Start: Map your present DWV system and calculate where you will need to tie new drainpipes into the main stack. Re member that, because the pipes rely on gravity to carry the flow of wastes, they must slope downward. Plumbing codes require that a horizontal run have a pitch of - inch for each foot of the run.

Check your plans against the local plumbing code before buying supplies or starting work. Most jobs that add new pipe must first be approved by building officials. Specify PVC plastic pipe: It’s easily cut and joined, and along with its fittings, has smooth, continuous inner surfaces that don’t obstruct waste flow. Get a plastic-pipe cutter or a backsaw and miter box to make the needed cuts, and use a utility knife or a file to remove rough burrs from cut pipe ends. To break into a cast-iron stack, rent a chain-type cutter.

--Venting the Drains: Vents re lease noxious gases outside the house and equalize air pressure so that waste and water can flow freely through the drains. A vent line runs from every fixture’s trap to a vent stack.

The trap-to-vent connection can be made in two ways: by stack or self-venting, in which the fixture’s drainpipe drains the trap and also vents it through the roof; or by individual or branch venting, in which a separate vent line links the trap to a central stack vent.

--Testing the System: You must test new drains and vents by filling the system with water. Repair any leaks that are revealed, and have a plumbing inspector check and approve the installation before you use the drains.


  • Plastic-pipe cutter, or backsaw and miter box
  • Utility knife
  • Sandpaper or emery cloth
  • Level
  • Hammer
  • Electronic stud finder
  • Dry-wall saw
  • Soil-pipe cutter
  • Hacksaw
  • Soldering iron
  • Electric drill with extension and hole saw bits
  • Plumb bob
  • Saber saw
  • Screwdriver
  • Pry bar
  • Garden hose
  • Awl or ice pick
  • 50-gallon drum
  • Dry-wall screws


  • PVC pipe and fittings
  • PVC primer
  • PVC cement
  • Nails
  • 1-by-2s and
  • 2-by-4s
  • Wood wedges
  • Perforated plastic- pipe strapping
  • Stack clamp
  • Joint compound
  • Pipe clamps
  • Solder and flux
  • Slip couplings
  • Flashing plate with rubber collar
  • Petroleum jelly
  • Roofing nails
  • Roofing cement
  • Test caps

= = = = =

SAFETY TIPS---Wear gloves to protect your hands while cutting cast iron, and a hard hat while working overhead, especially in an attic, where roofing nails may be exposed. When hammering or sawing, goggles help shield your eyes from flying chips.


1. Joining a closet bend and a sanitary T.


Typically, the heart of a new DWV installation is an assembly of three fittings: a closet bend, receiving toilet waste; a sanitary T, with a curved inlet for smooth flow; and a closet Y, joining both and providing another waste inlet.

• Dry fit these components to make an assembly long enough to center the closet bend under the toilet drain hole and the sanitary T under the stack hole. Add a piece of pipe to increase the assembly’s length, if necessary.

• Make alignment marks across each joint, to quickly assemble and orient the pieces after applying cement.

• Take the assembly apart, cut or file away the burrs around cut ends, and smooth them with fine sandpaper.

• Apply PVC primer to all assembly surfaces, inside and out, that will receive cement.

• Working one joint at a time, apply a thin layer of PVC cement to the inside end of the fitting and a thick layer to the outside of its matching piece.

• Push the parts together about 90 degrees out of line, then twist them until their alignment marks meet. Look for an unbroken bead of cement squeezing out all the way around the joint. If this bead is incomplete, quickly separate the parts, apply more cement, and rejoin. Hold the joint together for about 30 seconds.


2. Installing the closet-bend assembly.


• Dry fit lengths of pipe into the tops of the sanitary T and the closet bend that are long enough to reach above the floor when the closet-bend assembly is in place.

• Position the assembly, using a level to be sure that the sanitary T is exactly vertical.

• Nail a 1 -by-2 across the joist space beneath the assembly to provide support. Recheck the assembly’s position with a level.

• Use thin wood wedges to shim the pipes tightly into the floor openings.

3. Running pipe to the existing stack.


• To extend the assembly below the joists, dry fit a short piece of pipe and an elbow to the sanitary T bottom.

• Nail a perforated plastic strap to a joist on one side of the planned path of the new soil branch. If the pipe will parallel the joists, attach the strap to a 2-by-4 nailed across the joist space.

• On the other side of the branch path, drive a nail halfway into the same joist or 2-by-4. Use a nail with a head smaller than the strap holes.

• Fit a length of pipe into the elbow, loop the strap under the pipe, and hook the strap onto the second nail.

• Try hooking the strap by different holes until the pipe slopes down from the elbow at inch per foot. To check the slope (above), tape to one end of a level a strip of wood thick enough to center the bubble at the correct pitch (inset). For example, a 2-foot level requires a 0.5-inch strip.

• Couple and suspend more pipe to extend the branch, and cut the end to just reach the existing soil stack. Hang additional straps every 3 feet while maintaining the slope.

4. Bracing the stack for cutting.


To keep the top of the stack from dropping when you cut the bottom, add a brace where it enters the first floor.

• Find the point where the stack emerges from the basement. If it’s behind a wall, locate the studs with an electronic stud finder; then, with a dry-wall saw, re move a 16- by 10-inch rectangle of wallboard between studs at floor level to reveal the stack.

• Position a stack clamp around the stack (inset), about - inch above the soleplate or the floor; tighten the clamp bolts firmly.

• Drive wedges between the clamp and the soleplate or floor as shown at left.

• Attach 2-by-4 mounting blocks to the studs, and screw the wall board over the hole. Patch the resulting seams, then re paint the wall.


5. Opening the stack.


• Choose a sanitary T to fit the stack and the new soil branch, and hold it against the stack at the proper height to receive the branch. Mark the positions of the top and bottom of the T on the stack.

• Use a chain-type cutter on a cast-iron stack. Wrap the cutting chain around the stack and slip it into the hooks on the other side of the tool head. Position the chain 0.25 inch above the top mark on the stack, tighten the turn screw to compress the spring, and move the handle of the cutter up and down until the pipe separates. Make a second cut 0.25 inch below the bottom mark. Discard the cut section and stuff toilet tissue loosely into both ends of the stack.

On a copper or plastic stack, use a hacksaw to cut the pipe 4 inches above the top mark and 4 inches below the bottom mark. Save the re moved section.

6. Installing a T.


• On a cast-iron stack, slide a pipe clamp’s stainless-steel ring onto the bottom of the cut stack.

• Fit the neoprene sleeve of the clamp halfway onto the pipe and roll the free end of the sleeve back so the upper half folds over the lower half.

• Repeat the process on the top part of the stack, folding the free end of the sleeve up.

• Place the sanitary T in the gap of the stack and unroll the sleeves over it. Slide the stainless-steel rings over the sleeves; tighten the screws.

• On a copper or PVC stack, cut the removed section into two pieces, each as long as the depth of the collars on the T, plus 3 7/8 inches. Solder or cement these short lengths of pipe into the end collars of the T.

• Two slip couplings (far right) will be used to connect the T to the stack. Prepare the pieces of a copper assembly by burnishing all cut ends and the interior of the couplings, then applying flux to these surfaces. Rub the ends of PVC pipe with abrasive cloth.

• Slide a slip coupling over each stack end and place the T assembly in between. Position the lower coupling over the joint, and cement or solder it in place. Repeat with the upper coupling.

• Cement the dry-fitted parts of the soil branch.



Bathtub or shower.


• Run pipe from the tub or shower drain to the closet-bend assembly through holes in the joists , drilled at a slope of 0.25 inch per foot.

• Install pipe in joist holes by cutting lengths that fit between the joists. Push the segments through the holes and join them with couplings.

• Many codes require individual vents or long drain runs. Typically a 1.5-inch pipe may be no longer than 4.5 feet from stack to fixture; a 2-inch pipe may run 5 feet. To create a separate vent, substitute a long-turn (offset) T for a coupling in the drain run .

• At the closet-bend assembly, cement the pipe to the inlet in the closet Y. Don’t add the trap at the other end of the run until the tub or shower is in place.



• Remove the guide pipes dry fitted earlier to both the closet bend and the sanitary T.

• Simulate the height of the finished floor by stacking a piece of the planned flooring atop a piece of the underlayment on each side of the closet bend. Set the rim of the toilet flange on the flooring above the closet bend.

• Measure from the top of the flange’s hub to the bottom of the closet bend’s hub and cut a length of pipe to fit.

• While a helper braces the closet bend from below, cement the pipe into the bend.




The washbasin drain can be connected directly to the stack if no toilet on a floor above drains into the stack. (See below for an alternative drainage route.)

• Cut a piece of pipe to join the below-floor sanitary T to a smaller one positioned at the height required by the rough-in specifications for the basin drain.

• Dry fit the small T to the pipe, check its height, and make alignment marks. Cement the pipe and upper T to the lower T while a helper braces it from below.

• Inside the wall, dry fit pipe to slope upward from the inlet of the small T. End it with an elbow facing into the room at the rough-in lo cation for the washbasin drain . To the elbow, add a pipe extending 6 inches beyond the stud. Check the parts’ positions, then cement them together.


A stack for self-venting.


• Drop a plumb line from the top plate at the center of the washbasin sanitary T, and mark the position of the string on the plate.

• Mark a circle on the top plate, centered on the string position and slightly larger than the vent pipe. Cut out the circle with a drill with a hole saw bit.

• If the room above is floored, continue drilling through the flooring from below.

• Cut a length of pipe long enough to reach from the T to a point about a foot into the room above; angle the pipe into the hole, lower it to the T, and cement the joint.

Separate vent lines.


• To cut a vent from a tub or shower drain into the new stack, install a small sanitary T, bending upward, in the stack about 2 feet above the wash basin drain.

• From the long-turn T installed in the shower or tub drain line, route a vent pipe up through the soleplate and through the wall to the T fitting on the stack.


A shared vent line for two fixtures.


If your plumbing code lets you vent two traps with one line, you may be able to simplify your system (above).

• Extend the stack upward from the top of the below-floor sanitary T to a point at least 6 inches above the over flow drain of the washbasin.

• Run pipe vertically from the long-turn T in the shower or tub drainpipe, through the soleplate, to the level of the washbasin drain line. Install the washbasin drain sanitary T atop it.

• Complete the vent with a line from this T and through the wall to one in stalled in the vent stack. Extend the stack through the top plate.

• Connect the washbasin drain line to the washbasin sanitary T.


A connection in the attic.


Before connecting to an existing stack, test the new system, but in the attic rather than on the roof.

• After testing, add an elbow to the pipe extending into the upper story.

• Install a sanitary T in the existing stack, making the top cut in the stack first. The upper section of the stack may come loose at the roof as you work; if it does, have a helper hold it in while you install the T.

• Cut a piece of pipe long enough to join the elbow and the T. Cement it in place.

• On the roof, reseal the stack with roofing cement if necessary.



1. Marking and cutting the hole.


• In the attic, drop a plumb line from the roof to the center of the stack vent. Mark the position of the string, and drive a nail into the roof through the mark. (If the stack rises directly under a rafter, alter its course with two 45-degree elbows.)

• Climb onto the roof and find the nail. Mark a circle around it slightly larger than the pipe. Use a utility knife to cut away shingles within the circle.

• Drill a starter hole inside the circle, then cut around the circumference with a saber saw.

2. Securing the flashing.


• To waterproof the exit hole of the stack, install a flashing plate that has a precut hole and a rubber collar.

• Lubricate the inside of the collar with petroleum jelly. Slip the edge of the flashing under the shingles above the hole and align the collar over the stack hole. (If any shingle nails get in the way, remove them with a pry bar.)

• Lift the shingles that cover the top edge of the flashing and fasten the flashing with roofing nails.

• Use roofing cement to caulk exposed nailheads and shingles you may have damaged.

3. Installing the pipe.


• Cut a length of stack pipe to reach the distance above the roof that is specified by your code.

• Have a helper angle the pipe up through the collar. Hold the flashing in place from the outside.

• Permanently connect this uppermost segment to the stack pipe below.



1. Installing test caps.


When connecting a PVC soil branch to a cast-iron stack, prepare to test the system by applying cement to the inside of each open pipe. Press a test cap into place while twisting it.

For PVC or copper stacks, check your local plumbing code or with the plumbing inspector for regulations on testing the system.

2. Checking for leaks.


• With all drain openings blocked, pour water into the new vent on the roof to fill the drain system.

• It you find a leak, punch a small hole in the soil branch test cap with an awl or ice pick and drain the water into a large drum or divert it to a basement floor drain.

• Let the system dry overnight, then cut out the leaking joint and replace it.

• From the end of the run near the stack, cut off 0.5 inch of pipe containing the old test cap. Cement a new test cap onto the end of the pipe.

• Retest the system.

• When the system has been inspected and approved by your local plumbing inspector, drain the water as de scribed above.

• Connect the soil branch to the stack after removing its test cap. Use a sleeve and pipe clamp to join PVC to cast iron; a slip coupling and cement for PVC to PVC; and transition fittings for PVC to copper. Don’t remove other test caps until you are ready to connect the fixtures.



Getting Water to the Fixtures: The Supply System

You must tap into your home’s existing supply lines in order to bring water to your new bathroom. These pipes may be made of galvanized steel, plastic, or copper. Since galvanized steel is no longer in use and plastic is prohibited for supply lines by some local codes, copper is the material of choice.

To join copper pipe to steel, use a dielectric union—a five-piece transition fitting designed to prevent pipe corrosion. Copper can also be linked to plastic pipe with a two- piece adapter; a threaded copper coupling that is soldered to the copper pipe screws into a plastic collar, which has been cemented to the plastic pipe.

--Pipe Sizes: Local codes dictate the diameter of a branch supply line, based on the number of fixtures that are attached to it. Most codes require 0.5 inch pipe for one or two fixtures, 3/4-inch for three or more.

In the system shown, the cold-water line begins with 3/4-inch tubing because it feeds three fixtures—toilet, wash basin, and tub. The hot-water line is 0.5-inch; it supplies only the last two.

Installation: Choose the shortest, straightest route from existing lines to the bathroom, using angled fit tings to join lengths of pipe at turns. When measuring and cutting pipe, be sure to include the distance each segment will extend into the fittings at either end. Solder all the joints in the same manner as described for the T fitting that is shown.

Once you reach the bathroom, bring the branch lines up through predrilled holes in the soleplate, and attach 90-degree joints to extend them horizontally to the fixtures. We will show how to do this for the layout. Your sequence may vary, depending on where the branch lines enter the bathroom and where you install your fixtures.

- !! CAUTION !! - Use lead-free solder on copper pipes and a flame proof pad to protect near by wooden surfaces. Use a striker to light your propane torch to reduce the risk of fire. Don’t stand directly under a joint when soldering. Keep a fire extinguisher nearby, and turn off the torch before setting it down.


  • Tube cutter with built—in reamer
  • Flux brush
  • Wire fitting brush
  • Clean cloth
  • Striker
  • Propane torch
  • Hacksaw
  • Pipe wrenches
  • Plumber’s abrasive sandcloth
  • Flameproof pad


  • 0.5- and 3/4-inch copper pipe
  • Fittings (T, L, wing L, coupling)
  • Paste flux
  • Lead-free solder
  • Penetrating oil
  • Dielectric unions
  • Pipe joint tape
  • Test cap

SAFETY TIPS---Wear goggles, gloves, and long sleeves when soldering.


1. Cutting the supply line.


• Close and drain the system.

• Fit the jaws of a tube cutter around the section of pipe where the new line will begin. Turn the knob clock wise until the cutting disk bites into the pipe and the rollers grip the pipe.

• Rotate the cutter around the pipe, tightening the knob as necessary until the pipe is severed. For 3/4-inch pipe, cut the pipe again 1.5 inches away from the first cut to accommodate a T fitting (for 0.5- inch pipe, 1 inch away).

• Remove any burrs from the cut ends with the cutter’s built-in reamer.


2. Installing a T fitting.


• Clean the inside ends of the T with a wire fitting brush. Then dean the last ¾ inch of the outside surface of the cut pipe with plumber’s abrasive sand-cloth until it’s uniformly shiny. Don’t touch area, as oil from your hands can interfere with the bond of the solder.

• Brush a thin, even coat of flux on the cleaned area and fit the T over both ends of cut pipe .

• Proceed immediately to Step 3, before the flux dries.

3. Soldering a T fitting.


• Light a propane torch with a striker and hold it with the tip of the flame touching the underside of the joint between the T and the pipe until the flux starts to bubble.

• Hold the tip of the solder against the top of the joint. When the solder starts to melt, remove the torch. The solder will flow into the joint and seal the connection; examine it closely to make sure that the solder has filled the entire circumference of the joint. If there are gaps in the solder, reheat the joint and apply more.

• Repeat the process for the other joint. Remove excess flux and solder with a wet cloth after about 5 minutes.




1. Cutting and removing the pipe.

• Close and drain the system.

• With a hacksaw, remove a 2-inch section of steel pipe between two joints.

• Unscrew the resulting pipe stubs from the nearest joint collars by fitting pipe wrenches to the collar and stub as shown above. Holding the collar stationary with one wrench, turn the other to remove the stub. If the joint is corroded, squirt penetrating oil on it.

• Next, unscrew each collar with one wrench while holding the pipe stationary with the other.

2. Attaching dielectric unions.

To join steel and copper pipe, use a dielectric union, which consists of a steel spigot and a brass shoulder separated by a rubber washer and attached with a nut and collar.

• Screw the spigots of two unions onto the ends of the steel pipe, and measure the gap between the spigots.

• Solder a copper T between two copper pipes to make an assembly 1 inch shorter than the distance.

• Install the copper section by assembling a union on each end as shown above and tightening the ring nuts on the spigots. Use a pipe wrench to keep the steel pipe from turning. Mark the copper pipe at each brass shoulder, then take down the copper section.

• Slide a ring nut and plastic collar back to the T then clean inside a brass shoulder and outside the copper pipe. Apply flux and solder the shoulder at the mark. Repeat at the other end of the pipe.

• When the work is cool, wrap the spigot threads with pipe joint tape. Tighten the ring nuts on the spigots.



1. The toilet.

• Run the 3/4-inch cold-water line horizontally to the toilet location.

• Attach a 3/4- by 0.5- by 0.5-inch reducing T at the rough-in height of the toilet inlet.

• Cut a 6-inch length of 4-inch pipe to extend into the bathroom, and solder it to the T. Solder a test cap on the end.


2. The washbasin.


• Extend a 0.5-inch hot-water line below the hot-water rough-in point for the basin and install a 0.5 inch T.

• Install a 0.5-inch cold-water sup v me from the toilet T under the cold-water rough-in point of the washbasin.

• Attach a T to the cold-water line at 45 degrees and add enough 0.5-inch pipe to clear the hot-water line by 4 to 6 inches, then attach a 45-degree 4-inch elbow—or L—so that it’s pointing up.

• Fit the hot-water T and the cold-water L with 0.5-inch vertical pipes—called risers—that extend to the height of the fixture. At tach a 90-degree L to each riser, then add a 6-inch length of pipe to each of them.

• Seal the ends with test caps.

3. The tub and shower.


• With pipe clamps, secure a tub-and-shower valve body to the support installed earlier. Then screw the three valve stems into the valve body.

• Run 0.5-inch hot- and cold-water supply lines horizontally through the studs and up to the valve body, using 90-degree L’s.

• Run a 0.5-inch pipe from the shower outlet of the valve body up to the height of the shower- head. Solder a 0.5-inch brass wing L to the top of the pipe and screw the sides, or wings, to the wood support. Screw a 0.5-inch capped shoulder nipple into the threaded opening of the wing L.

• Install 4-inch pipe from the tub-filler outlet of the valve body to the level of the tub filler. Add an L and a 6-inch-long piece of pipe and seal with a test cap.

• Test the entire supply system by turning on the water and checking carefully for leaks. Wait at least 24 hours before concealing the pipes or mounting fixtures.



Installing a Tub or Shower

The first fixture to install in a new or renovated bathroom is the bulkiest—the tub or shower. As noted earlier, planning how to get the fixture from outside the house into the bathroom is essential; for ex ample, in many homes a molded tub- and-wall unit can be brought in only through a patio door from which the sliding-glass panels have been re moved. To simplify tub and shower installation, do the work before fully enclosing the bathroom.

-- Three Bath Options: Made of heavy cast iron or of lighter-weight fiberglass, plastic, or steel, a standard 5-foot bathtub like the one shown remains a popular choice. Instructions begin (below) for installing two common alternatives: a tub-and-wall unit, which offers finished walls and the least chance of leakage, and a shower stall of pre fabricated panels, which is compact and easy to clean.

-- Framing to Match the Fixture: Tubs and shower pans alike can rest on either the subfloor or the underlayment. Select whichever is convenient; if you are installing new subfloor in the bath area, you don’t need to add underlayment, but if you are preparing an old floor, you can leave the underlayment in place.

When you are installing a standard tub, strip the wall beside it to the bare studs and add a horizontal support. For a tub-and- wall unit or for a shower stall, construct a separate three-wall enclosure against a bathroom wall as shown.

-- Protecting the Finish: Avoid standing in the new fixture. If you must step inside, pad the bottom with cardboard and blankets.


  • 2-by-4s
  • 1.25-inch roofing nails
  • Tub waste and overflow kit
  • Plumber’s putty PVC drainpipe and trap
  • Supply pipe
  • Fiberglass insulation with vapor barrier
  • Mortar mix
  • Construction adhesive
  • Shims
  • Silicone caulk
  • Flameproof pad
  • Moisture- resistant wall board
  • Solder
  • J bead
  • Sealant
  • Shower and bath fittings


  • Hammer
  • Screwdriver
  • Pry bar
  • 1.25-inch hole saw
  • Pliers
  • Trowel
  • Corner bead
  • Electric drill with 1/8-inch bit
  • 2-foot level
  • Caulking gun

SAFETY TIPS---Wear work gloves, a face mask, and safety goggles when working with fiberglass insulation. Also wear safety goggles when you hammer nails.

1. Placing the tub.


• For a cast-iron tub—which can weigh 300 pounds or more—lay 2-by-4 runners on the floor (left). Enlist three helpers to get the tub onto the runners. Two people can push the tub into place. Rest the tub rim on the horizontal support installed earlier.

Handling a fiberglass, plastic, or steel bathtub requires at least one helper.

• For a fiberglass or plastic tub, lay a supporting bed of mortar before setting the fixture in place.

• With all three materials, drive a 1.25 inch roofing nail into each stud, over lapping the flange with the nailhead; use a nail set to avoid hitting the tub.



2. Adding waste pipes and overflow pipes.


• Place a slip nut and washer on the overflow pipe and the waste pipe of a waste and overflow kit, then loosely connect both pipes to the waste T. Slide the pipes in the T to fit them to the tub’s drain and overflow openings. Tighten the slip nuts.

• While a helper holds the assembly in place, attach the overflow plate to the lift linkage for the stopper. With the trip lever in the up position, hold the linkage against the overflow pipe at the center of the range; adjust the length of the linkage so that the stopper is at the right height block the waste pipe (inset).

• Have your helper place a large rubber washer, supplied with the waste kit, between the overflow pipe flange and the outside of the tub. While the helper holds the pipe in place on the washer, lower the lift linkage into the pipe and set the overflow plate against the inside tub wall. Connect the plate to the overflow pipe flange with screws supplied in the kit.

• Next, ask your helper to place a washer on the waste pipe flange and then hold the assembly firmly against the underside of the tub at the drain opening. Press plumber’s putty under the flange of the crosspiece, and screw the crosspiece into the drainpipe by hand.

• Tighten the crosspiece by inserting pliers as shown earlier and turning clockwise with a pry bar.

• Attach the strainer to the crosspiece.

3. Connecting the trap.


• Working under the bathroom floor, add a tub trap to the end of the horizontal tub drainpipe, trimming the pipe so the inlet of the trap is directly beneath the tub waste T. If necessary, use an elbow and a short piece of pipe to center the trap.

• Measure and cut a pipe to serve as a tailpiece between the trap and the waste T.

• Join the waste T, the pipe, and the trap with slip nuts and washers (left); avoid cementing the trap so it can be removed if necessary for service.



1. Framing and insulating.


Before you frame for a tub-and-wall unit, check the manufacturer’s instructions for special support requirements.

• Construct a three-wall enclosure of 2-by-4s against a bathroom wall to fit the tub-and-wall unit; locate the enclosure’s plumbing wall so that you will be able to access it from behind after the unit is in place. Build the enclosure to the ceiling, doubling the studs at the end of each side wall. Provide for nailing surfaces in both the side wall and back wall where they meet. If the unit has a grab bar, add 2-by-4 backing for it.

• Frame for the tub’s drainpipe and supply pipes, then run the pipes. After testing the supply pipes, desolder and remove the tub spout pipe stub. Wait to install it, as well as the shower arm and faucet stems, until the unit is in place.

• To muffle the drum of shower water on the unit’s wails, staple fiberglass insulation between the studs with the vapor barrier (covered side) in (left). Don’t insulate the stud space containing the supply lines.

2. Measuring for openings.


• Dry fit the tub-and-wall unit into the enclosure, and mark the back with locations for the shower, spout, and faucets. Lift the unit out and transfer the marks to the inner face by drilling a 1/8-inch hole at each one; have a helper press a block of wood against the inside of the unit to keep the fiber glass from cracking as you drill.

• Without standing in the tub, drill 1.25-inch holes through the inner face with a hole saw, using the smaller holes as guides.


3. Setting the tub unit.


• To support the bottom of the tub, spread a bed of mortar, mixed to the consistency of damp sand, about 1.5 inch deep.

• If the unit includes a grab bar, apply construction adhesive to the back of the unit behind the bar before setting the unit in place.

• Tilt the tub-and-wall unit and push it into the enclosure (inset), then lower it onto the mortar. If the unit sits too high, quickly remove it and ad the mortar bed.

• Add the waste pipe, overflow pipe, and trap as for a standard tub, then attach the shower arm and showerhead and faucet stems and handles. Working behind the unit with a flame proof pad, solder the stub for the tub spout, then attach the spout.

4. Nailing and finishing.

• Shim between studs and the flanges on the top and sides to fill any gaps.

• Fasten the tub-and-wall unit to the studs with 1.25-inch roofing nails driven through predrilled holes in the flanges; drill additional nail holes if necessary. While hammering, use a shield of cardboard or thin plywood to protect adjacent fiberglass surfaces (far left).

• Finish the walls above and beside the tub-and-wall unit with wallboard that is moisture resistant. Before in stalling each wallboard piece, push a length of J bead onto the edge bordering the unit, mitering the metal channel to a 45-degree angle at corners.

• Lay a bead of sealant along the in side corner of the flange. Set the wall board J bead in place, into the sealant, and screw the wallboard to the studs.

• Cover other exposed studs with moisture-resistant wallboard, finishing corners with metal corner bead (near left). Hide seams with wallboard tape and joint compound.



1. Marking for the shower pan.


• To allow for the back wall of the shower-stall enclosure, place a length of 2-by-4 against the wall in the planned shower location.

• Turn the shower floor, or pan, upside down and set it against the 2-by-4 spacer. With a pencil, out line the pan on the floor.

• Stand a short length of pipe that is 2 inches in diameter in the drain hole. Steady the pipe as a helper lifts the pan and sets it aside, then use the pipe as a guide to draw a circle on the floor showing where the shower drain will go.

2. Installing the shower pan.


• Frame and insulate a three-sided shower enclosure as for a tub-and-wall unit, establishing the side walls inch outside the penciled outline of the pan.

• Add supports for a showerhead and faucets.

Draw a large X through the planned center of the drain, then cut a 5-inch-square hole around that point, leaving the ends of the X as reference. Run supply pipes and drainpipes, leaving the shower arm and faucet stems until after the panels are in place. For a shower, the trap may be located either under the pan drain or at the end of a drainpipe leading to a wall beside the enclosure.

• Some shower pans—but not all—are meant to be supported on a mortar bed. Check the manufacturer’s instructions and lay the mortar if it’s called for.

• Set the shower pan securely on the floor inside the en closure, and level it with shims if necessary.

• Fasten the shower pan flanges to the enclosure studs with roofing nails.

3. Connecting the drain.


Shower pans may be connected to a drainpipe by any of several systems. In the example shown here, a rubber, doughnut-shaped seal from the shower kit fits tightly between the pan’s drain hardware and the drainpipe. After pressing the seal in place, screw on the strainer.


4. Cutting holes for plumbing.


• Dry fit the side panel that will house the plumbing connections, seating it on the pan flange below. Mark the panel from behind with the positions of the faucet and shower arm connections as with a tub-and-wall unit if access permits. Otherwise, measure the location of each pipe from the end stud and transfer those measurements to the panel.

• With a 1.25-inch hole saw, cut openings in the panel for the shower arm and faucet stems.

5. Assembling the shower stall.


Since sealant dries quickly, try for a speedy installation. Avoid smearing sealant on shower stall panels; it can be hard to remove.

• Run a bead of sealant in the back flange of the shower pan. Set the back panel in the flange, temporarily holding the panel in place with a roofing nail just above its top flange.

• Apply sealant to the channel on the right edge of the panel and to the right flange of the pan; add sealant to the right side panel’s edge.

• Put the side panel on the pan flange and inter lock the edges of the back and side panels. Lightly anchor the side panel with a nail above the flange.

• Install the left panel the same way.

• Check that the panels meet snugly and remain square and plumb to the pan; if necessary, shim under the flanges. Then secure all three with nails just outside the flanges, using a punch or nail set to avoid scarring the finish.

• Finish the walls above and beside the panels as with a tub-and-wall unit. Add the shower arm and showerhead, faucet stems and handles, and a shower curtain and rod.



Completing the Room

Depending on the extent of your bathroom project, you may need to add new walls—a step best per formed after installing the bathtub and any other large items. An ordinary partition wall resembles the wet wall that is described previously, but with one difference. The studs and soleplates and top plates of a partition wall are 2-by-4s rather than 2-by-6s, because no plumbing must be concealed inside the wall.

Installing a door in such a wall is a simple matter of nailing a factory made, prehung door to the sides and top of a rough doorframe built as part of the partition. Buy the door assembly ahead of time, and use its measurements as starting points for the built-in doorway.

--A Sequence of Final Steps: Before hanging the door, you probably need to arrange for a rough-in inspection for each permit. In most areas, these inspections take place after the walls are framed but not closed and the ducts, wiring, and pipes are in place but not connected to any fixtures.

Once these inspections have been completed, close the walls with moisture-resistant wallboard or, where it’s needed, cement board. Then paint the ceiling, finish the walls, and put in the finished floor. See Section 7 for floor- and wall-surfacing techniques. Hook up the lighting and the appliances, and then complete the job by adding a door, a sink, and—as depicted below—a toilet.

--Hanging a Door: A prehung door assembly (below) consists of two halves that are pushed into the rough doorframe from opposite sides of the wall. The door itself comes hinged to the inside of one of the sections, with the casing and doorstop already attached to the top and side jambs.

Many doors come with predrilled doorknob holes and bolt channels. To install a doorknob-bolt assembly—using a lever knob for greater accessibility—drill a hole into the jamb for the bolt; chisel mortises on the door and jamb for the bolt and strike plates.


  • 2-by-4 studs
  • Nails
  • Wood shims
  • Spacing blocks
  • Prehung door
  • Doorknob assembly

SAFETY TIPS---When hammering, wear safety goggles to protect your eyes from flying debris or loose nails.

1. Building the wall and doorframe.


Construct a partition wall of 2-by-4s using the methods noted earlier, but avoid nailing the soleplate near the area that must later be cut for the doorway.

• At the planned door location, install two outer studs, spacing them 3.5 inches farther apart than the width of the prehung door’s top jamb.

• Cut two jack studs 1.25 inches shorter than the top of the top jamb. Nail them to the outer studs flush with the bottoms of the studs.

• Place two headers, one atop the other, across the tops of the jack studs and nail them in place.

• Attach a cripple stud between the double header and the top plate.

• Cut away the soleplate between the jack studs where the doorway will be.



2. Installing the prehung door.

After closing the wall and applying a finished surface, install the prehung door.

• Remove the shipping braces holding the door assembly together. Prehung doors are often nailed closed for shipping free the door before installing the assembly.

• Plan to attach the section containing the door first; if the second section will be installed from inside the bathroom, ace it there before beginning.

• Slide the first section into the opening in the wall.

• Insert three 1/8-inch spacing blocks between the strike side the door and the side jamb, and two blocks between the top of the door and the top jamb.

• Nail the casing to the rough doorframe.

• Remove the blocks, open the door, and walk through.

3. Completing the job.

• From the other side of the wall, insert two 0.25-inch tapered shims between the top jamb and the rough frame, and three between each side jamb and the frame.

• Break off the excess portion of each shim. With the door open, secure the shims in place by driving nails into the jambs, through the shims, and into the frame.

• Slide the other half of the door assembly into position so that it fits snugly into the first section; the two attach with a hidden tongue-and-groove joint.

• Nail the casing to the wall.

• Nail the jambs to the frame at 1-foot intervals.

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Special Forms of Wallboard for a Bathroom

Ordinary wallboard becomes soft and spongy in a damp setting, so its use should be avoided for bathroom walls. Instead, close the walls with moisture-resistant wall board, or with cement board for areas you intend to tile. Moisture-resistant wallboard, called “greenboard” for its green, water face paper, has a core saturated with asphalt to resist absorption and softening. Cut arid install greenboard as you would any wallboard, but don’t employ it on ceilings, where it has a tendency to sag; ceilings are the only bathroom surface for which ordinary wallboard is often used.

Cement board, commonly available under the trade name Durock, consists of an aggregated Portland cement held together by fiberglass mesh. To cut it, score through the surface skin of cement and the mesh below with a utility knife, making several passes and substituting new blades as necessary. Then snap the board along the cut, and plane the edge with a rasp. Alternatively, cut cement board with a circular saw and a carbide-tipped blade; wear safety goggles and a dust mask. Make any necessary holes by scoring the desired shape onto the cement board, then smashing out the marked area with a hammer. Cement board should be secured in place with 1.5-inch hot-dip galvanized roofing nails or with special screws called wafer-head fasteners. Space the nails or screws no more than 8 inches apart.

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Hooking Up a Toilet

Begin toilet hookup by installing a shutoff valve and a plastic toilet flange (below) if you moved a toilet drain or added one during a bath room renovation. Before cementing the flange in place, remove the rag that was stuffed into the drain earlier, then replace the rag until you are ready to set the toilet. If you are installing a new toilet on an old drain, you usually can use the existing flange and valve; start with Step 3.

In either case, the new toilet’s dimensions must match the wall-to- drain distance in your bathroom. Furthermore, water-conserving toilets, which have been mandated by federal law since 1994, require the use of a 3/8-inch supply tube between the shutoff valve and the toilet tank.

To conceal the bolts anchoring the toilet to the floor, there are plastic caps available that snap in place and there are porcelain caps that are secured with putty.


  • Shutoff valve
  • Toilet flange
  • PVC cement
  • Toilet flange screws
  • Wax gasket
  • Plumber’s putty
  • Closet bolts and caps
  • Toilet supply tube

1. Attaching a shutoff valve.


• Cut the supply pipe 2 inches from the wall, then slide an escutcheon over the stub and press it against the wall.

• Slip the compression nut and compression ring that came with the valve over the pipe.

• Position the valve on the pipe with the outlet hole pointing up. Tighten the nut one turn past finger tight.

= = =

2. Seating the flange.


• Apply PVC cement to the inside of the flange stem and the outside of the waste pipe. Push the flange onto the pipe so that a line drawn between the bolt slots is perpendicular to the wall, as shown at left, then immediately rotate the flange a quarter-turn, positioning the slots an equal distance from the wall.

• Drill through the screw holes into the subfloor (on a tile floor, use a masonry bit). Secure the flange with toilet flange screws.

CAUTION---Work quickly when you are setting a toilet flange; PVC cement dries permanently within 30 seconds.


3. Attaching the wax gasket.


• Turn the toilet bowl upside down and set it on padding.

•Slip a wax gasket over the ridge around the waste hole.

•With your fingers, press the gasket firmly against the bowl bottom.

4. Setting the howl.

• Insert a closet bolt head downward into each bolt slot (inset), positioning them equidistant from the wall.

• Lower the bowl onto the bolts. Press down firmly on the bowl, rocking it slightly. Don’t raise it from the floor; doing so will break the seal between toilet and drain.

• Level the bowl from side to side and front to back. If necessary, shim with copper or brass washers without lifting the bowl up.

• If using plastic bolt caps, slip a cap base onto each bolt, followed by a metal washer and a nut. Tighten the nuts finger tight, then a quarter-turn more with a wrench. Trim the bolts with a hacksaw as needed and snap the bolt caps in place.

• For porcelain caps, secure each bolt with a washer and nut, then attach the caps with putty.

5. Connecting the water supply.


• Attach the toilet tank as shown earlier, and bolt on the seat and cover.

• Wrap plumbing-sealant tape onto the threads on the shutoff valve and on the base of the ball cock, which protrudes under the tank.

• Screw the compression nut on one end of a toilet supply tube to the outlet hole on the shutoff valve; fasten the coupling nut on the other end to the ball cock.

• Open the valve, flush the toilet, and check for leaks. If necessary, tighten the nuts a fraction of a turn at a time until the leaks stop.

Friday, March 14, 2014 16:21 PST