Home Decoration -- Preparing Surfaces

To achieve the best possible finish, all surfaces must be adequately prepared before they are decorated. This section shows you how to get the best results on large areas such as walls and ceilings, as well as techniques for treating wooden surfaces such as doors and smaller areas of exposed decorative woodwork.


Previously painted walls, in good condition, need little preparation -- usually only minor filling and sanding—before redecoration. If a wall is papered, remove the paper and make sure the surface is smooth. On a wooden surface, good preparation is the basis for a professional finish. See below for preparing wooden elements or features.


Shave hook: Strips paint from a wooden surface, whether flat or ornate.

Wallpaper scorer: Perforates paper to let steam or water through. Essential for removing vinyl (waterproof) papers.

Wire brush: Used to remove debris and clean off flaky surfaces, such as a metal pipe.

Heat gun: Blisters paint and makes it easy to remove from a wooden surface. Must be used with caution.

Steam wallpaper stripper: Electrically operated. Steam flows from a hot-water reservoir to a stripping pad and bubbles the paper, easing its removal.

Sanding block: Easy to grip, with a sanding surface on one or more sides. You can make your own by folding sandpaper around a squared- off block of wood.

Sandpaper: Paper with a rough face that smoothes surfaces. Grades vary from the fine to the very rough.

Steel wool: Cleans down metal surfaces and is used to apply wax. Comes in various grades of coarseness.

Filler: Ready-mixed fillers are the most popular choice for DIY work. Powder filler is mixed with water into a stiff, creamy paste and used to fill holes in wood, plaster, and masonry surfaces. Once dry, you can sand it to a smooth finish and decorate. Most fillers designed for use with natural wood finishes are ready-mixed; other types accept the color of stains or dyes. The other main type of filler is caulk, which is used along cracks in ceilings, walls, and woodwork.

White-tinted shellac: Applied to knots in wood before primer or further coats of paint, to prevent sap from weeping from the knot.

TSP: Powdered soap mixed with water and used to clean down surfaces before they are rinsed. Allow surfaces to dry before decoration.

Spray-on stain block: Blocks out stains that show through normal coats of paint. Can also be bought as a “paint” in cans. May be water-based or solvent- based; water-based versions dry faster.

Mineral spirits: Solvent used for most oil-based paints.

Brush cleaner: Restores brushes.

Hand cleaner : For easy removal of paint, grime, and grease.


Stripping wallpaper: Drop cloths, steam stripper, warm water, garbage bags

Washing down and filling: TSP, hot water, sponge, oil- based undercoat (optional), brush, spackle, 2-in (50-mm) knife, sandpaper

Filling cracks: Caulk, caulk gun, sponge, brush, oil-based undercoat*


Steam strippers work most efficiently when top layers of paper have been removed, exposing the more absorbent backing paper. The impermeable surface layer of vinyl papers often peels dry, relatively easily. Always follow the manufacturer’s guidelines. Wear protective gloves, if the tool’s manual recommends them, and goggles. Steam and drips may burn, so take all possible precautions to protect yourself. Never use a steam stripper to remove paper from a ceiling. Instead, simply soak the paper with warm water and then scrape the paper off the ceiling surface, an option that can also be used on a wall if you prefer.

A. Lay drop cloths over the room, and remove as much loose paper from the wall by hand as you can.

B. Fill the stripper with warm water before plugging it in. When it starts to steam, place it flush on the wall.

C. Hold the pad completely flush on the wall surface. After 5 - 30 seconds, move it along and scrape paper off the wall in the steamed area. The thicker the layer(s) of paper, the longer you will need to hold the pad in place. But do not hold it still for too long or the wall surface itself may crumble.

D. Work your way across the wall, steaming areas and removing paper.

E. Continue removing paper. Put it in a garbage bag as you remove it, so that it does not stick to the drop cloth or other surfaces.


After a wall has been stripped, wash the surface thoroughly to remove all traces of adhesive. Use soapy hot water to sponge the wall. Then rinse with clean water. You can now repaper the wall. If you wish to paint the wall, apply an oil-based undercoat before a water-based latex paint. However well the wall has been cleaned, traces of adhesive may bleed through a water- based paint; oil-based undercoat prevents this. It is needed on a previously painted wall only if the wall is in poor condition.

A. Clean out the hole with a dry brush. Apply filler by pressing it in place with a 2-in (50-mm) knife. Deeper holes may need filling twice because spackle contracts as it dries.

B. Once the spackle has dried, sand it back to create a smooth surface flush with the surrounding area.


Cracks are best filled using caulk. It is supplied in a tube and is applied along cracks or joints with a caulk gun. It can't be sanded, and must therefore be smoothed by hand before it dries. Some caulks may be over-painted when dry. Choose a latex caulk if you think you may paint. Others need an oil-based undercoat to prepare them for water-based paints, which may crack if there is no undercoat. A ceiling-wall junction is shown here.

A. Clean out the joint. Prepare the sealant and gun. Apply even pressure to the trigger, moving the gun along the joint.

B. Gently smooth the sealant with a wet finger. You may also use a damp sponge to smooth the caulk.


Plaster in a good condition can be directly over-painted with full-strength paint, Alternatively, first apply a mist coat of diluted latex paint (1 part water to 10 parts paint), which provides a base for further coats. Drywall ceilings must be coated with a special sealer before paint is applied, otherwise paint may dry differently on the board than on the jointing compound.


Woodwork provides the finer detailing in a home and its finish is a stamp of quality. To produce good results you must prepare surfaces, including doors, windows, and decorative woodwork for moldings or paneling.


Using a heat gun: Shave hook

Solution stripping: Old paintbrush, scraper or shave hook, cloth, mineral spirit or water

Paste stripping: Filling knife or small trowel, stripper, covering cloth, cleaning cloth, neutralizing solution/white vinegar, water

Covering old paint: Oil-based eggshell paint, paintbrush, brush-cleaning solution, mid-oak wood stain, varnish, oil, or shellac, two cloths

Priming and filling before painting: Knotting solution, paintbrush, filling knife, sanding block, filler, primer

Filling for a natural wood finish: Filling knife, filler, sanding block

Stripping wood

A good finish is often achievable by recoating the existing surface. However, you may need to strip woodwork before redecorating—the existing coating may be so bad that it can't be successfully recoated; it may be painted, but you want a natural wood finish; or it could have a natural finish but you want to paint it or apply a different finish. Beware of surfaces with lead-based paint, which is toxic and now found only in older properties. It is a health risk if heated with a heat gun, and fine particles created by sanding are also toxic. Paint-testing kits are available to identify lead-based paintwork.


A. Turn the heat gun on and direct the nozzle at the wood surface, leaving a gap of a few inches between the two.

B. After a few moments, the paint will begin to soften and bubble, which point use a shave hook or scraper to lift the old paint free.

C. Move the gun along to the next area and repeat the process. Use a shave hook to remove paintwork in recesses, such as on paneling.


- Take great care using a heat gun. Wear goggles and a respiratory mask, and perhaps gloves. Take any other precautions that are advised by the tool’s manufacturer.

- Do not hold the gun for too long over the wood, to avoid the risk of scorching it or even setting it on fire.


A. Wearing gloves, a mask, and goggles, use an old paintbrush to apply the stripper. Use dabbing strokes to build up a good layer of the stripper on the wood’s surface. Allow it to soak in and react with the paint. This may take only a couple of minutes or up to half an hour.

B. Once the paint has bubbled up, scrape it off using a scraper and /or a shave hook.

C. Thoroughly clean the surface afterwards. Mineral spirit and cold water are usually best, but check the stripper manufacturer’s guidelines.


A. Apply the stripper with a filling knife or small trowel to a depth of about in (2.5 mm) -- or deeper if there are many coats of paint.

B. If your manufacturer specifies it, cover the entire surface with a special cloth. Leave for 24 hours. Use a scraper to peel away the paste.

C. Thoroughly clean down the area. If the manufacturer suggests it, use a “neutralizing solution”; or use white vinegar and then clean water.


Removable items such as doors can be “dipped” professionally. The whole item is submerged in a tank of powerful chemicals, which lift all traces of paint from the wood surface. Many companies offer a pickup and delivery service.


Sometimes a natural wood finish may not be possible—if the wood is too rough, or the paint too ingrained to strip. Old beams may have stained finishes or may have been painted at some stage. You can have the paint sand- blasted away by a professional company but this is expensive, and extremely messy. An alternative is to apply the paint effect shown here.

A. Completely paint the beam, using an oil-based white eggshell.

B. Apply a wood stain over the top of the eggshell. A mid-oak color is very effective.

C. Rub varnish, oil, or shellac across the whole surface to provide the effect of an oak beam.

D. After half an hour, buff off the varnish, oil, or shellac with a clean cloth. Some will remain embedded within the wood grain, resulting in the appearance of a natural wood beam.


Natural wood beams are often tricky items to prepare for decoration, because of flaky surfaces and often very crumbly edges where the beam meets plaster. Trying to fill the edge is difficult and often ineffective, as the filler too crumbles and falls away.

One way to secure the edge is to apply a clear matt varnish to the beam, overlapping slightly onto wall or ceiling surfaces. The varnish both binds the surface and provides a natural look. The wall or ceiling paint may then be cut in along the edge to create a neat finish.


Wooden surfaces are seldom completely smooth. Filling dents and sanding improves the finish. The type of filler to be used depends on whether the wood is to be painted or a natural finish applied. If it's to be painted, use powder filler—flexible filler can be used in joints or cracks. If a natural wood finish is to be applied, use a “stainable” filler the same color as the finish. See this page for choosing a suitable primer.


A. Prime bare wood before using filler, to make it adhere better. Primer also makes it easier to see areas that require filling. If wood is painted, use primer only if there are large, bare patches—for instance, on external woodwork. Any knots in bare wood must first be coated with knotting solution.

B. Allow primer to dry. Mix up filler, and apply to holes, dents, or divots, using the flexibility of a filling knife blade to press in the filler.

C. Allow filler to dry. Sand to a smooth finish. Deep holes may require refilling and sanding to provide the best finish.


A. Apply colored putty to holes in the wood surface with a putty knife. The putty color should match the natural wood finish to be applied.

B. Once the putty has dried, sand it smooth. Then apply coats of your chosen finish.



Sandpaper should be chosen according to the condition of the surface. So, for rough surfaces, begin by using a rough paper. As the surface becomes smoother, reduce the coarseness of the paper.

Remember that sanding produces dust. This should always be brushed away before a coating is applied. A vacuum cleaner nozzle is ideal for removing dust from baseboards or the profiles of moldings.

The best finishes are normally achieved when the wood has been wiped down with a damp cloth before coating, removing the finest residues. This is essential when sanding flat surfaces such as window sills.

Monday, November 3, 2008 21:04 PST