Q: What is the best way to prevent knots from leading to rot in a wood deck surface?
A: We recommend sealing knots with stainable, shrink-resistant, exterior-grade wood filler prior to application of a preservative stain/sealer. To minimize the mess, mask off the area with painter’s tape and apply only enough product to fill the hole. Filling the hole will reduce the likelihood of water accumulating in those low areas of the deck surface, where it could otherwise work down into the wood grain and contribute to rot. Although many wood fillers are marketed as “stainable,” the degree to which the product will readily accept the stain’s intended color tone will vary. The easiest approach is to select pre-colored wood filler that closely matches the tone of stain/sealer you intend to apply to the decking.