How to Paint Exterior Wood Siding

Painting exterior wood siding usually involves a lot of arduous preparation, especially if your house has gone too long between paint jobs. If your home is very old, with decades of built-up paint layers, expect to spend a lot of time removing old paint. With newer homes, power-washing, scraping, sanding and priming is not usually as time-consuming. Skimping on preparation, not using primer and using budget-quality paint will all dramatically shorten the life of your paint job and compromise your home's siding by allowing wood to crack and rot. Look at exterior painting as a way of protecting your biggest investment: your home.

Weathered wood needs to be cleaned, scraped, sanded and primed.
  1. Look at the job and make sure you have the capability and equipment to do it. Run your hand over the wood siding on the sunny side of the house. If a chalky residue comes off on your hand, you will need to power wash or scrub your home, because this chalking will impair paint adhesion.

  2. Power wash your home if it is chalky or very dirty. You can add mildewcide and siding detergent to most power washers to get rid of stubborn dirt, mold and mildew. Power washing will also remove some of the loose paint.

  3. Scrape off the remaining loose paint with a chisel-edged paint scraper. If your house is old and has multiple layers of paint, you may want to consider using solvent-based paint strippers or a heat gun to remove the old paint, but be aware that these methods are potentially dangerous. Check with your homeowners insurance carrier to make sure you are covered for these activities.

  4. Sand weathered wood and remaining paint with an electric palm sander and 60- or 80-grit sandpaper. This both provides a smoother surface and improves the adhesion of paint and primer.

  5. Prime all bare and weathered wood with high quality acrylic or oil-based primer.

  6. Caulk joints and gaps between the siding, but do not caulk along the bottom of each siding board because this doesn't allow moisture to escape from within the house. Use exterior spackle or epoxy wood filler for nail holes and gouges in the wood.

  7. Apply two coats of 100 percent acrylic house paint once the primer has dried according to label directions.


  • If your home was painted prior to 1978, it may have been painted with lead-based paint. Contact your local Environmental Protection Agency for laws and procedures covering the removal and handling of lead paint.