Asked on Jun 15, 2012

deck boards are weeping sap......

Woodbridge Environmental Tiptophouse.comKMS WoodworksScott R


I replaced all of the horizontal 5/4 PT pine boards on my deck about 9 months ago. Let them dry out 6 or more months until this past April. Started applying solid color deck stain, and it went on just fine. No problems. About 3 weeks ago I started noticing that some sap was weeping through the stain just on a few boards and wondered what that could be from. Any ideas? Is this normal? What should I use to scrub the sap off? Turpentine or some other solvent?
4 answers
  • You can clean this off, but most likely It will begin to come back. Decking boards should not have any knot areas of any kind. I would take some photos and bring them to the store where you purchased the lumber. Tell them you want them to exchange this lumber for new boards.

  • Scott R
    on Jun 16, 2012

    these are not knot areas though. they're just random areas, long stretches, with sap.

  • KMS Woodworks
    on Jun 16, 2012

    Your stain may have caused the sun to warm the boards gain on the wood. This added heat can cause wood to ooze sap. you may have some limited result trying to clean these up...( with thinner) but it can often take years for this sap to cure hard enough to not ooze.

  • In any case, it should not be happening. You spend a lot of money on this material and it should not happen. Photograph it, and go to the supplier and ask for replacement wood.

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