What can I use to rid my composite deck of pine sap? We have a lot of trees and a lot of sap.—Patricia Anderson, via email
There are plenty of tricks for removing pine sap from materials and surfaces; for spot treatment, we’ve recommended both vegetable oil and hand sanitizer. (See “Talk Dirty to Me,” Spring ’18.) Ideally, you’d ask your decking manufacturer for product-specific advice. But if you can’t, go with the gentlest option: good old (mild, biodegradable) soap and water.
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For ease of application, since you’re talking about “a lot” of sap, Leslie Adkins, of composite deck and dock maker Trex Company, recommends a pressure washer, ideally with a soap dispenser and a fan attachment. But be careful: just as pressure washers can damage wood, they can damage composite. Protect your boards! Don’t use anything stronger than 3100 PSI, says Adkins. “After giving the deck a good rinse, spray on some soap and gently scrub with a soft-bristled brush.” Rinse off the deck and let it dry.
Done! Maybe. If the sap has left stains, and the discolouration is enough to bother you, try a deck brightener, says Adkins (check hardware stores). Don’t use bleach or chlorine—that could affect the deck’s surface and colour.
Got a question for Cottage Q&A? Send it to answers@cottagelife.com.
This article was originally published in the March/April 2025 issue of Cottage Life.
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