What Chemical Do I Use to Strip a Deck?

Reason To Strip

• Stripping a deck is a process that removes old sealer, stain or toner from the wood's surface. Removing the film from the deck reveals the wood's bare layers for applying new stain, toner or sealer. The new film application must absorb into the wood's top layers for weather element protection. Applying new film without stripping will not protect the wood correctly, possibly causing damage over time from the weather.

Chemical

• The chemical used most commonly within the deck stripping industry is sodium hydroxide. This chemical works best on oil-based stains and sealers, as opposed to newer latex-based films. You can apply the stripper with a brush or roller. Alternatively, you can spray the chemical onto the deck using a pump sprayer.

Pressure Washing

• Once the stripper is applied to the deck, pressure washing is necessary to remove the harsh chemical and any film residue. Most strippers should be removed from the deck after 45 minutes. The pressure washing generates a clean deck surface for applying new sealer or toner.

Considerations

• If hiring contractors to strip a deck, confirm that they are applying sodium hydroxide with a pressure wash afterward. Sealers and toners must have sodium hydroxide applied for proper film removal. The old film cannot be removed correctly and completely with just a simple pressure wash. In addition, make sure that standard bleach -- which can harm the wood's finish -- is not applied to the deck.

Warning

• Sodium hydroxide is especially effective for stripping decking since it is an extremely caustic chemical. Also known as lye, workers need to be careful handling the chemical. Sodium hydroxide can cause burns and irritation to skin. In addition, the chemical's fumes can burn the body's airways. Make sure to apply the stripper in an outdoor environment for ample air circulation. Use gloves while handling the chemical as well.