Once everything was stripped out of the bathroom and I had decided to expand the footprint of the shower stall, I was left with the challenge of figuring out the best, most cost effective way of getting the perfect shower (for that space). There were a few problems with finding a shower pan. First, because we removed one wall, and the 2" thick cement on the other walls, the drain was no longer centered to anything. Previously, the inside of the shower measured 36"x 44". The new measurement (maxing out the space) is 45" x 46". My choices for a shower pan were as follows: prefab fiberglass/resin, custom crafted mud shower pan, or custom fabricated marble or corian. Wino thought we should just do a custom mud/cement pan and tile it. I know my limitations, mostly, my lack of patience, and was wary of this project. I found a really good video online explaining how to build one of these shower pans. After watching the video, Wino suggested we find an alternative. Smart boy. I found a few websites offering preformed shower bases in a material that could be tiled, to give it a custom look, but the size was not exact and the drains were centered and that meant we would have to move the drain and make the shower smaller by building in the walls, ruining the line of the bath and adding a lot more work. Apparently, standard sizes run 42"x 42", then jump to 48" x 48". I stumbled across a website that offered custom sized bases in a material that would take tile. Actually I found two different products, made two different ways. I chose the one with the simple installation, since the material was basically the same. I was surprised at the quote because it wasn't much more than a prefab tile-ready base, but it was twice the cost of a prefab fiberglass base (once you slap "custom" on anything, it seems to skyrocket the price). If we wanted to keep the size and drain location, this was the best choice. Basically, the base is made of extruded industrial hard foam, formed to specifications, then skinned with a thick waterproof fiberglass mesh/plastic/resin surface that mortar will stick to. The base comes with a 4" threshold, but can also be made ADA compliant. There's also a 5" flange that goes up the wall to help with waterproofing. Check out the details
here. So we order it, I'm excited because the shower is going to be big and this seems like a relatively simple solution. It comes in a huge box, but is very light weight. On the order form, it suggests you minus 1/2" from the dimensions for wiggle room. Well, our space is not quite square, with one end being 1/4" smaller than the other, so I only minus 1/4" off the smallest dimension. When we dry fitted it, it didn't fit in the back corner and I had to remove some furring strips to make room. No big deal, I reinstalled them after the shower base was in. So take the 1/2" wiggle room to heart. The base basically gets glued down using the same modified thin-set used to adhere the tiles. The drain was replaced first, we ordered a new one with the pan. It's three pieces, quite clever. Lots of thin-set, gobs of 100% silicone around the rim of the drain flange, and try to place the pan level without dropping it. Ugh. Once it was in, I stepped into the base to force it down, squishing out any excess mortar. It was pretty level when I checked it so we didn't have to do anything there. My paranoia about the drain led to a 20# weight being positioned over it for 3 days, until I was sure it was set. The modified thin-set is designed to stick to plywood but we chose the extra protection of using cement backerboard over the plywood on the entire floor. We put in some screws about 1/2" from the top of the flange to secure the base to the wall studs.
So the base was in and we continued to install the walls. Heres where the drama happened.
My feeling on this shower base is that it's a little delicate until the tile is installed. I was concerned with something puncturing the surface, negating it's waterproofing. I'm always dropping tools, screws, tape measures, and I thought something might happen. Well, when we were putting the walls in the shower stall up, we needed a step ladder for the top piece. I told Wino, "get the rug pads and some wood to spread out the weight of the ladder feet so they don't puncture the base" (see picture).
Guess what happened. He didn't want to go look in the garage for scrap wood and thought I was over-reacting so he just used the bunched up rug pads and ended up puncturing the base, not once but twice! Now I'm picturing water
penetrating the grout, running down the base towards the weep holes in the drain but being diverted into these potholes, seeping into the foam and collapsing the whole base. I have an active imagination. Wino was banished from the bathroom and I finished the walls myself (we were mostly done). To fix the pothole problem, I filled them with high grade silicone caulk, and decided to look for a waterproofing product to apply to the whole base as a precaution. More on that in the "shower wall and waterproofing" post.
To sum up, I would use this base again, at this point. I'm procrastinating tiling it but so far, it's performed as advertised. Installation was straight forward, and if you can mix mortar (but no lumps!) it's really easy. In the future, if I used this product again, I would be more cautious about the surface until the tile is in. Stepping on it with shoes or bare feet is fine, but ladder feet, not so much.