waterproofing a tub deck

[David Zaret]

i'm building a tub deck from QS sapele. i've landed on the approach of brushing the underside and edges (focusing on the end grain) with west systems epoxy, and using waterlox for the top surface (consistent with the rest of the sapele in the house). does anyone see an issue with this approach? i would think the epoxy will do a great job of sealing the wood and still being flexible enough to move.. and six or so coats of waterlox should.... uh... lock out water?

thanks for any advice.

--- dz

[Shawn Pixley]

I don't think it will work long term. Even in shower pans, the waterproofing is often a membrane under the tiles.

There are two issues. Waterproofing the deck and protecting the sapele. You'll want some type od membrane below the Sapele (not epoxy on the back side of each board). If then the sapele is to be a deck that isn't immediately dried, then the waterlox is the wrong finish. I would defer to the most expert what the right one is (maybe a marine or spar varnish).

[David Zaret]

to be clear, i do not expect water to contact the area that i hit with epoxy. it's purely preventative. i agree completely that any surface water needs to be removed ASAP.

thanks for the help.

[Shawn Pixley]

Sorry, from your description, I envisioned a spa tub deck that would be wet after use.

That said, I don't care for Waterlox on the top an epoxy on bottom. I fear that it will trapp water in the wood leading to other issues. I am a waterlox fan though I don't think it is what I would use for this condition as it does not form film as well as others. Maybe if you have pictures or could further describe it?