Sealing treated plywood seams
Tiziano
| Posted in General Questions on
I’m doing a raised floor assembly on piers, 6″ to 20″ off grade (over 20 mil poly and 4″ of rock). Minnesota. All that is installed and ready.
Bottom sheathing is AC2 ground contact plywood (although none will ever touch the ground). That arrives tomorrow.
What would the best seam and edge sealing material be? I had planned on ZIP tape, back when I was going to use ZIP panels. Then I went to Liquid Flash.
Now I’m wondering if I need something else due to the switch to treated plywood instead of ZIP? Water will rarely, if ever touch this, but humidity, heat, and freezing temps will.
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Replies
Giving this a bump since nobody answered. I think any of the various flashing tapes would be fine. 3M, Siga Wigluv, etc. This is a relatively benign environment for those tapes and they should all last relatively long.
I don't love the use of 20 mil plastic under the gravel. Unless the soil is very carefully graded, any low spots will collect water and with limited airflow and cool conditions, these puddles can be very slow to dry. The space under the floors will always be relatively cooler and wetter than the outside air whether you have the plastic or not. So unless this is going to be an enclosed and conditioned crawl space, I would skip the plastic and just use gravel to make it less comfortable for critters. I am probably nearly alone on that opinion, though. It seems that the plastic is a routine recommendation.
Thanks Peter.
Plastic and rock are already in place so I’m stuck with it. I’m sure there are low spots, but the center is kind of humped, with all sides sloping outwards.
As for the tape…
I’ve got some ZIP but will look into Wigluv.