Prep and Paint Wood Siding

Prep and Paint Wood Siding

A good exterior paint job will protect your house from the elements, saving you the higher cost of extensive repairs. This project will help you with previously painted wood siding, but many of the procedures and advice hold true for other types of siding and exterior surfaces. You can apply latex paint over oil-based paints (unless there are three or more coats of oil-based paint on the house) but you cannot apply oil-based paints over latex ones. Always buy the best quality paint and applicators that you can afford.

This project can be very time consuming, so paint one side each year and take the fifth year off.

There are a surprising number of hazards associated with house painting. With care and the proper equipment, however, you can minimize the risks.

Caution: Be very careful around overhead electrical wires, especially when moving ladders around or painting near where service lines attach to the house.
Familiarize yourself with basic ladder safety procedures. Be wary of bees and wasps, especially when you are on a ladder. Follow directions and safety warnings on paints, chemicals and cleaners.

Tools & Materials

  • Canvas and plastic drop cloths
  • Pruning shears and tree saw
  • Safety goggles
  • Exterior paintable caulk and gun
  • Dust masks
  • Utility knife
  • Paint clothing, hat, etc.
  • Screwdriver
  • Ladders
  • House wash
  • Paint scrapers with extra blades
  • Pressure washer (Rental item)
  • File (to sharpen scrapers)
  • Soft scrub brush and bucket
  • Electric disk or random orbit sander (Rental item)
  • Garden hose and nozzle
  • 60-, 80-, and 120-grit abrasive disks
  • Masking tape and/or plastic sheeting
  • Paintbrushes & Power sprayer (Rental item, shown)
  • Paint (topcoat)
  • Primer
  • Paintbrush/roller spinner
  • Exterior spackling compound
  • Paintbrush comb
  • Polyester resin or auto body filler
  • Paint bucket swivel-type hanger
  • Plastic squeegees and putty knife

1. Evaluate Existing Conditions
Examine the entire surface of your house looking for problems such as peeling paint, open joints or seams, wet or rotted wood, mildew (black or gray spots), and other problems. You should identify, understand, and repair or otherwise resolve problems and their causes before you pick up a paintbrush or paint sprayer. Discuss any major problems with your paint dealer or a reputable paint contractor.

Tip: A good pair of binoculars makes this process easier.

2. Remove Loose Paint
Remove all peeling or flaking paint. Although there may be cases where chemical stripping, heat guns or other approaches may be more appropriate, sanding and scraping are by far the most common ones. Cover the ground with canvas drop cloths to catch the paint chips. You may want to use a shop vacuum to clean up any chips that do get on the ground. Scrape first, using as large a scraper as is appropriate for the surface. Rent a disc sander with 60-, 80-, and 120-grit sanding discs. (For very limited areas you can use a random-orbit sander, a hand sander, or a disc sander drill attachment.) Begin sanding with the coarse abrasive and finish with the fine one. Pay particular attention to smoothing (feathering) the edges between painted and scraped areas. Painting will accentuate, not hide, any ridges and edges that you leave.

Caution: Always wear eye protection and a tight-fitting dust mask when scraping or sanding painted wood.

Tip: Sharpen and/or replace scraper blades often. A dull blade increases the likelihood that you will damage the wood, because it requires you to use more pressure and you have less control. Keep the sander moving constantly to prevent heat, caused by friction, from softening the paint and gumming up the paper.

3. Scuff-Sand Surface
If the surfaces are glossy, sand them lightly to remove the gloss. This will improve the bond between the new and old finishes.

4. Prime Bare Wood
Paint will not bond to wood exposed by sanding. Apply an exterior latex or oil-based primer with a brush to all bare wood and allow it to dry completely.

5. Patch Damaged Wood
Use an exterior spackling compound or, for larger damaged areas, a two-part polyester resin filler (such as Bondo) to repair any holes or damaged wood. Apply it with a plastic squeegee and sand the cured filler to make it smooth and level with the surrounding wood.

6. Caulk
You probably noticed that the previous paint film peeled or flaked most often near joints between dissimilar materials (siding/trim, window frames/glass, etc.) This is because water seeps into cracks and soaks into the wood, ultimately causing the paint to peel off. Use an old screwdriver to scrape out any failed caulk from joints and cracks. Use compressed air and/or a brush to clean the joint. Allow any moisture to dry completely before applying new top-quality paintable caulk.

Tip: Do not caulk the horizontal joints between siding courses or the vertical joints between members in the same course. These joints permit moisture behind the siding to escape.

7. Cut back Vegetation
Cut off tree branches that overhang your house. Prune or remove foundation plantings that are less than 2 feet from the house.

8. Clean the Exterior
Rent a pressure washer to thoroughly clean your home's exterior. Or use a soft scrub brush and a detergent/water solution to remove all dirt and grime. If mildew is present (black or gray spots), it must be killed with bleach. Ask your paint dealer to recommend an appropriate house wash that includes a mildewcide. Allow the house to dry for at least two to three days in dry weather before painting.

Tip: A power washer can also be very helpful in removing loose paint. If you use it for early prep stages, you still need to wash off the sanding dust at this stage.

9. Make Final Preparations
Remove light fixtures and other hardware so you don't have to paint around them, or cover them with plastic and masking tape. Remove shutters so you can paint behind them. (Save painting the shutters for a rainy day in the garage.) Cover shrubs, the ground, and walkways with canvas drop cloths. Slide window screens up behind storm windows or remove them. Set up your ladders.

Tip: Don't mask until the last minute, and remove masking tape shortly after you complete painting an area.

10. Paint the Surface
Anyone will tell you that preparation is nine-tenths of the work. So here's Step 10 - the fun part. Start at the top and work down to apply the topcoat to the body of the siding with a paint sprayer. Then paint the trim with a paintbrush. Follow the manufacturers directions relating to weather, temperature and damp surfaces.

Tip: Avoid painting in direct sun. The rule of thumb states, "Follow the sun." Allow the sun to warm a surface and to move around to another side of the house before you start painting the warmed surface. Also, avoid painting in windy conditions that can blow dirt and insects onto the wet paint or cause the paint to dry too quickly.

As you paint, carry sandpaper, a scraper, spackling compound, a putty knife and caulk so you can clean and patch any defects that you may have missed.

11. Final Inspection
Check your work carefully, inspecting for missed spots, spills, drips and other problems.

12. Finish Up

Once the paint is dry, reinstall removed items such as light fixtures, hardware and shutters. Do a thorough job cleaning brushes, paint sprayer and other tools, and store them properly. Store leftover paint in a small well-sealed metal can, or dispose of it properly.

WARNING: If you scrape, sand or remove old paint, you may release lead dust. Lead is toxic. Exposure to lead dust can cause serious illness, such as brain damage, especially in children. Pregnant women should also avoid exposure. Wear a NIOSH-approved respirator to control lead exposure. Clean up carefully with a HEPA vacuum and a wet mop. Before you start, find out how to protect yourself by contacting the National Lead Hotline at 1-800-424-LEAD or log on to www.epa.gov/lead

This article is owned by True Value and was reprinted on this site with their permission.

Comments