How to Install Mortar Shower Pan Membrane Liner

Hi, I’m Mark Donovan from HomeAdditionPlus.com and today I'm going to show you how to install a mortar shower pan for a ceramic tile shower. The first thing you need to think about when building a mortar shower pan is the framing structure of the shower and as you can see here, basically we have our 2 x 4’s on 16-inch centers around the frame of the shower. You’ll notice that in the corners we have blocking material so we can allow tile backerboard to firmly stood up against the 2x 4’s or 2 x 16 if you use them.

If you look over here, what we have is block and we put in for the shower fixture and if you noticed near the edges here, we’ve got some additional blocking in so that when the door that gets installed on the shower’s tile has a surface area that mount to. You need a base of the shower, you’ll notice that without it’s 2 x 2 blocking along the perimeter of the shower and this is to add after some of the form but also to hold the shower membrane liner material that we’re going to attach to it shortly.

Second of all, we’ve added three quarter inch plus another half inch of plywood on top of the three cornered sub-floor to really get a nice firm solid base. You really want to make sure there’s no flexing going on. I’ll see you find your tile on the cracking over time.

We’ve also put in equivalent three2 x 4’s, the use of 4 x 4 plus one 2 x 3 for the curve and this is then liquid nailed and glued as well as screwed to the floor into floor joists so this is nice and ragged. Finally, you’ll see we have adjustable shower drain assembly here. The first step is to remove the adjustable drain barrel and the drain clamping mechanism from the base drain system.

And then I’m just going to apply some duct tape here in the base of the drain assembly just to make sure we don’t get any type of mortar and other texture material into the drain while we do our work.

So, what I’ve just done is like put in 15-pound felt paper on the base of the flooring up against the sides an inch and two. The felt paper access is a slope sheet between the mortar and between the tile in the base sub-floor. Second of all the felt paper helps to avoid the moisture from the felt or on from mortar waking into the wood as it cares. So the nest thing I’ve done is that middle out in the base of the shower pan to access the reinforcement for the mortar mix.

I’m just using a staple gun to hold it in a place or in the floor. You want to make sure it’s flush so it doesn’t penetrate up and out of the pre-slope mortar. So what we’ve done now is to take a pencil in a straight edge and I draw a line along the primer of the shower wall area approximately one-inch above the base of the sub-floor and this is such that it’ll create gentle about a quarter inch per foot slope toward the drain.

The drain itself is approximately half inch above the base of the sub-floor so when we go out and put a mortar in one and half in slope upwards, again in approximately one inch of the base of the floor in this particular case.

So, what I’ve done now is I mixed up a bag of mortar, cement mixing quickly mortar with three quarts of water. This is 60-pound bag and I troweled it in to the shower pan area such that it slopes up from the drain to the lines that I put on the perimeter of the shower wall. You let to set it up over night and then tomorrow I’ll return and put in the shower membrane liner itself then backerboard in one final liner reinforcement mortar on top of it.

So prior to putting the mesh with membrane liner down and bring felt material on the framing walls and then we’ll put the cement board on top of that at least to on half way down then I’ll put the membrane liner on and then finish up with the cement board. Now I'm actually installing the cement backerboard to the walls at least for the first upper five feet of the new membrane liner. To pour one install in the backerboard and using a handset mortar, you put the rough side facing outwards. In addition, you want to use the rock on screw specifically designed for door.

I began to install the shower membrane liner basically unfolding on over the corners and tucking in with roofing nails approximately six inches off the base on the floor. Once I got two quarter in, I’m now going to move toward actually cutting up of the hole for the drain. So now that I have fold in a cup corners of the shower membrane liner basically trying to expose the bolts by drawing an x over each of the bolts and then pushing the bolt through. Now, I can cut out the center of the drain assembly to expose the drain. So now I’m going to run it and be cursorily can cut around the perimeter outside the edge of the base drain assembly such that we form the tight seal with the underside of the shower membrane liner.

I cut out four notches for the weep hole areas. They’re associated with the clamping bracket. Now, I just lay to clean blocking and I’ll turn kind of clockwise, lock it in place, and I’m going to take it up for the wrench. And so now, I’m putting the barrel drain head in to the clamp, just screwing it down to approximately the depth of the mortar that we’re going to put in for the final reinforcement layer. But however with the mortar level and by a quarter inch to take on account the finish tile that will set up flush with it.

So, I’m just wrapping up the folds over the curve now and tucking it in on the outside edge. You don’t want to put any nails weeping else on the top or the inside edge or else you have a leaking problem. Now that we’ve completed installing shower membrane liner I’m going to go back and put the main backerboard along the base to within one inch of the base of the shower pan itself. All right, so I completed installing the backerboard. A couple points I wanted to make was that you want to make sure you have a grout fault and some cardboard down to protect the membrane as you’re standing around and putting in the screws.

Second, I want to make sure your screws don’t go any lower than six inches in base of the shower pan so don’t mix.

And then finally what is the silicon caulk and all this seems to prevent any water sipping around the sinks. So now, we’re going to set the height on the drain barrel to approximately 1 ¼ inch so that one by one each of material of mortar here lead us to quarter just base of the tile. We’re going to slope this up against slightly to about 1 3/8 at the edge of these walls to get the right slope and then finally just before you put the mortar in around this weep hole areas. I’m going to put a few pebbles in to make sure that the mortar doesn’t clog any where near the weep holes. This is so that anywhere of the dust work its way down through the mortar and hits the membrane liner will go out to the weep holes into the drain.

So now I’m going to process and actually trowelling out some mortar. Once I get enough in the bag of the pan, I’ll then pour it with the different mortar trowel but as you can see it working from the drain area outwards. So now all I’m doing is flooding water smoothing out nice and I’m more nearly done. All right two more of the curve, I put metal at over the curve and nail it on just the very outside. Well, then add mortar now to complete the job.

All right so now I’m trowelling out the curve basically floating it on all three sides. You can just see we’re start to get a nice square shape. We’ll just do this a little bit more and we’ll be done. So that’s it for installing a mortar shower pan and let this set up for about 24 to 48 hours and get ready to install this ceramic tile. If you want more specific instructions and detailed pictures and diagrams visit HomeAdditionPlus.com and order our shower pan membrane liner in E-book. Again, if you have other home improvement questions visit us in HomeAdditionPlus.com today.