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How long do I need to wait before staining a new pressure treated deck? I will use an oil based penetrating stain.
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I usually suggest that a product like Thompson's Water Seal applied soon after installation will help keep the top of deck boards from cupping the wrong way due to sun exposure. It's not a long lasting product and almost all of it will be removed with a light pressure washing. It may take several months for the P.T. to be dry enough for your stain to be somewhat consistent. Good choice on the stain: Oil base, transparent or semi-transparent.
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You just need to know it's really dry. I like to wait till the green fades away. So that might mean waiting till the next year.
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Not a fan of Thompson’s Water Seal. I’d wait a year and then use the oil stain.
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(07-17-2022, 09:35 AM)goaliedad Wrote: How long do I need to wait before staining a new pressure treated deck? I will use an oil based penetrating stain.
You need to wait till the lumber has lost most of the water it can. So how long is that? Last summer I worked on a Rails to Trails project building bridges (search Mendota Trail to see some dandy bridges of my design). Southern Yellow pine, the most commonly used wood for treatment) dries exceptionally fast. Days were 90 degrees. Judging by weight, at daytime of 90 degrees with good air flow the lumber was dry enough to stain in 2 weeks. Somewhere else with cool rainy weather the time could be several weeks. Nowhere is it a year.
You can test. You must have some remaining lumber from this job. Leave a cut-off out on the deck with exposure on all 4 sides. Check its weight every few days. When it is light and stops getting lighter your deck will be as dry as it is going to be given that it is summer.
Check the tag that came on the end of the lumber. Look for fine print. If it says UC3B you got lumber that will last. If it says UC3A it has half the treatment chemicals in it as 3B and you may suffer early deck decay. We built bridges with a treatment level UC4B which has 4 times the treatment chemical as 3A. 4B has to be special ordered. The treatment now used will not make the lumber green like when "CCA" treatment was used. Our lumber was actually light yellow brown.
Bill Tindall
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(07-17-2022, 09:35 AM)goaliedad Wrote: How long do I need to wait before staining a new pressure treated deck? I will use an oil based penetrating stain.
if your building it now and beings how youre in TC give it a year.
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I agree with MstrCarpenter. You need to give this deck every ounce of protection you can and that starts with new wet wood.
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