Simple Home Repairs: Exterior Painting
Department of Environmental Design
A house needs repainting if the paint is blistering, cracking, scaling or peeling or if the wood or metal is deteriorating.
- Water-based and oil-based paints
- Paint primer (different for wood and metal)
- Linseed oil
- Wire brush and steel wool
- Paint scraper
- Cleaning solution for mildew putty
- Wood sealer
- Caulking compound
- Putty knife
- Paint brushes
- Paint rollers
- Paint bucket and paddle (or stick)
- Two stepladders and cross planking
- Possible additional needs
Determine the type and amount of paint required. Measure the length and multiply to determine how many square feet you need to cover. Subtract for large openings such as picture windows and sliding glass doors. The paint container will tell how much surface the paint will cover. If mildew has been a problem, get a paint with a mildew inhibitor.
- If the surfaces are free of defects, make sure that they are also completely dry and clean. Brush off loose dirt. If grease or oil stains remain after you use a detergent, try a solvent such as turpentine.
- For best results, use the same type of paint (oil base or water base) as the old paint.
- Caulk all holes and cracks.
- Replace all damaged or decayed wood. For areas of suspected decay, check around windows, steps and posts, and under and around the eaves. Check downspouts and gutters and clean them before painting.
- Prime all new wood with a paint primer. Seal any knot areas with a wood sealer after you apply the priming coat.
- Clean rust from all metal areas, using a wire brush and steel wool. Then apply a metal primer to the areas cleared of rust.
- Check all exposed nail heads for rust. Use steel wool to remove rust. Then sink the nails with a nail set, prime the nail head with a rust-inhibiting primer and fill the nail hole with putty.
- Clean off defective paint, using a scraper, wire brush or steel wool. For mildewed surfaces, wash the area thoroughly with an alkaline cleaning solution such as chlorine bleach. When defective paint is removed, apply a priming coat.
- Smooth rough places with sandpaper.
- Choose a day for painting when rain or heavy winds are not expected. Don't plan to paint if the temperature is likely to be below 50 degrees Fahrenheit, or above 90 degrees Fahrenheit.
- Follow the directions on the paint can.
- Three-coat painting is usually recommended on new surfaces. On old surfaces, two coats are recommended if painting is done every 5 years, or one coat if painting is done every 3 years.
Several thin coats of paint look better and last longer than fewer thick coats.
- For each coat, use paint from the same manufacturer.
- Don't buy paint too far ahead of time, since ingredients, especially in oil paints, will settle in the bottom of the can when kept in storage. Your dealer can shake and mix the paint with a machine.
- Avoid painting surfaces while they are exposed to direct sunlight.
- Place dropcloths over areas or objects that may be damaged by paint drops.
- Make sure that the paint is thoroughly mixed. Oil paint should be stirred frequently during use.
- It's best to paint from a small bucket. Pour only the amount needed from the original can and replace the cover each time.
- Never dip the brush more than one-third the length of the bristles. Then pat off the excess paint. This will avoid dripping paint as you move the brush from the bucket to the surface.
- Apply paint according to the manufacturer's directions.
- Begin painting at the highest parts of the house and work down. This will avoid spilling or dripping on surfaces already painted.
- When painting flat surfaces, apply the paint first in long, horizontal strokes. Then cross the horizontal strokes by working up and down (Figure 1). This will give a completely covered surface and use less paint.
- To avoid brush marks, always end up the painting of an area by brushing back toward the area already painted.
- When painting circular objects such as downspouts, apply the paint first diagonally. Then cross the diagonal strokes by working downward along the long dimension (Figure 2).
- Paint around edges with a brush before rolling the major surface.
- A roller requires less skill and is faster than using a brush. A roller works best on large flat surfaces. Use a brush for small areas and trim work.
- With a roller, apply the paint from a tray instead of a bucket.
- Place the paint roller in the tray; roll it back and forth to fill the roller cover with paint. Remove the excess paint.
- When rolling the paint on the surface, roll from the unpainted area into the painted area (Figure 3).
- Apply a small amount of pressure with the final stroke. The roller will pick up any excess paint from the painted surface.
- Make sure that each coat is thoroughly dry before beginning another coat.
- Always follow the manufacturer's instructions regarding the toxic nature of paints. Keep paints and painting products away from children.
- Keep the work area clean before, during and after painting. Dispose of waste each day.
- Make sure the ladder is secure. Do not overextend reach.
Painting protects surfaces from deterioration and helps avoid more costly repairs are avoided later.