I recently had to replace the entire floor in a custom tile shower. The
original had a lead shower pan that had deteriorated over the years and was
leaking. I had to tear the whole thing out down to the subfloor and have
replaced the lead pan with a vinyl pan and filled with mortar in preparation
for the new tile floor. My question is, should I seal this mortar with a
masonry waterproofer like Thompson's or UGL Drylok before installing the
tile with thinset mortar?? My thinking is this will help prevent
moisture/water from seeping down thru the mortar bed in the first place.
My concern is, will the tile thinset mortar bond with the mortar bed if I
treat it with one of these sealers. I don't want to have tiles popping up
6 months down the road.
Thanks for your help,
Ask your tile distributor about liquid membranes. Most contractors are using
this now. No need for any type of pan when these are used. You pour your
concrete apply the membrane and the tile thinsets to the membrane. A much
With a correctly installed pan, as you describe, there is no need to seal
the concrete the pan is meant to hold any seepage.
Don't do it! If your vinyl liner is installed properly there is no need. Did
you put a pre-slope in under the liner(give it some fall to the drain)? How
far up the wall did you run the liner? It should go up higher than the curb.
You should have a clamp type drain with the liner run under the top flange
and clamped down tightly. You also should haveput some small gravel under
the weep holes of the drain to keep the mud from clogging them.
Yes, I believe the liner is installed properly. I did everything you
suggest including a 1/4" per ft sloped (to drain) mortar bed under the pan;
30 lb roofing felt over that (cut around drain); two full sheets of 40 mil
PVC liner run up 6" above the curb behind the durock on the walls and up and
over the curb with all folded corners and no cuts; conducted overnight leak
test with water filled pan; placed small pea gravel around weep holes; then
laid 1-1/2" thick mortar bed with formed concrete curb to avoid nailing thru
The sealer for the mortar bed would minimize the amount of water that
actually gets to the liner and sort of be extra insurance for preventing
future problems. My theory is the more water that goes down the drain over
the tile, means less that hits the pan, creating less chance of perhaps
clogging weep holes and/or eventually finding some other way past the liner.
I guess I probably seem paranoid, but if you've ever had to do this job
(removing a 3-sided glass shower door, tearing out tile floor, old mortar
bed, lead liner and drain, remove tiles and durouck 2' up all walls, repair
damaged subfloor, and then replace everything you just tore out including
the ceiling in the room below) trust me, you will want to ensure you never
have to do it again.
Thanks for the advice,
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