AFTERTHOUGHT: Making of a waterproof sauna floor.

After having completed all the work from my previous post (http://outdoorsaunabuildmndiy.blogspot.com/2016/01/making-of-sauna-floor.html) There are some steps that I either made improvements on, or wish I had made improvements on. Here they are in no particular order.

DuRock Over Sauna Stove:

For the DuRock protection hanging above the stove, if you recall, we made the 2” air gap using scrap pieces of DuRock. Using those scraps did not make the structure feel solid to me. Instead, I ended up removing those spacers and installing two 2x4s going the width of our DuRock sheet where we previously had the scraps. Once the 2x4s were in place they felt solid-- they were screwed in to the joists in the ceiling through the first piece of sheetrock. Since a 2x4 is actually only 1.5” thick, we added one scrap piece of DuRock in each attachment point over the 2x4 to make up the .5” and give us a full 2” air gap. With the scrap between our protective DuRock and the 2x4, we were able to install the final sheet of DuRock to the 2x4. It was then a solid install as the 2x4s were great anchors for the DuRock and we had the required 2” air gap.
http://outdoorsaunabuildmndiy.blogspot.com/2016/03/hanging-durock-protection-on-ceiling.html

Attaching Waterproof Membrane To Walls:

The next change I realized I way too late is where the waterproof membrane went up the walls in the hot room. If you recall from previous photos, I installed the membrane over the bubble foil insulation on the bottom edges of the walls. Such an install has a chance of condensation running down the bubble foil and UNDER the waterproof membrane instead of in to it. So if I could go back, I would make sure the membrane is nailed to the walls and the bubble foil then would go over the membrane (instead of under). Also, where the foil goes over the membrane, it would NOT be stapled in place (to protect the membrane and keep it waterproof).

Waterproof Membrane Seam On the Floor:

Finally, if you again recall, I ended up having 2 pieces of the waterproof membrane that overlapped each other going down the center of the hot room floor. I held off gluing them together until I was ready to install the drain. However, before gluing them, make sure that the piece that overlaps on top of the other piece, allows for the water to flow freely from top piece to the down piece towards the drain. In other words, make sure the seam between the two pieces does not hold/stop the water from draining towards the drain. I hope that makes sense.