How to Make a Sunken Shower With Heated Tiles




Introduction: How to Make a Sunken Shower With Heated Tiles

About: I've been attempting to build a house mostly by myself for the last five years... I finally more or less finished it before the bunker project and after recovering from cr...

I looked at handicap accessible showers when I first began building the house because I knew my wife's arthritis was going to get worse as time went by. I wanted to be able to roll a wheel chair into it without getting bumped by a lip or edge and shower curtains have always just bugged me so I thought and thought and decided I could build one specifically to my tastes from tile for the same or less as a prefab one would be. I asked a few people and was told the way they used to do it was with a shower pan, which is basically a thick sheet of rubber like a pool liner that you use to seal the floor and then cement over and finish with tiles. They make a special drain that secures around the hole you need to cut in the rubber water tight and then a second drain screws into it to allow for about an inch or two of cement and tile putting the finished drain flush with the surface.

The house took me seven years to build so by the time I was ready to actually tile the room they had come out with some heated floor systems for warming tile floors and I splurged and went with a single ribbon system instead of the mat system since my floor was oddly shaped.

I got it on EBay and can't remember what I paid but I think it was around $600 for the entire kit including a thermostat that keeps the floor just a few degrees above the room air temp. You can get bigger systems to actually heat the floor but that seemed to expensive and unnecessary in Florida.

Step 1: Getting Started

Since I designed this house I had a lot of leeway as far as moving a wall and inch or two if something wasn't gonna fit very well but that's a last resort kind of thing. If you're going to use standard sized tubs or showers you need to remember to set your wall back far enough so the finished dimension is what you need. By this I mean don't make the mistake of framing in for a 60 inch tub then finding only 59 inches after you sheet-rocked the room kind of thing and remember if you use half inch backer board and tile you also need to allow for the width of the tile and mortar.

I went as far as making the exact finished dimensions in a manner that minimized the amount of tiles I would need to cut. This might not be that big a deal if you're just doing one room but I did all my bathrooms, hallways, entranceways and the kitchen floor in tile so I had to put down about 1700 square feet of it. A little planning ahead goes a long way if you're just in the designing phase...

I used backer board for the walls of the masterbath and the heated part of the floor but in the rest of the house I did mudpans which if I remember I'll do another Instructable on and link HERE. ( )

I chose not to heat the base of the shower itself because I didn't see anyway a low current system could keep up with water flowing over it's surface and I had to line the subfloor with a sheet of shower pan and didn't want to pierce it with the cable guides and I was also worried about running the heating coils up against the rubber. I didn't see much point in heating the floor under the vanity either so I chose the size of the heating strip accordingly, which was about 45 square feet.

Step 2: Sinking the Floor

Basically to sink the shower and not need a lip around it I cut a wedge out of the floor joists sloping to the back of the shower and dropping 3 inches, about 5 feet long stopping where I built the shower bench. I wanted this to be a gradual slope since I didn't want anyone to slip.

I then framed in the seat and I plywooded all the walls of the bathroom since I did that to the entire house for hurricane protection. The shower pan / sheet of rubber, you basically just spread out on the floor and up about 6 inches on the walls and staple along the edges only. You don't want to pierce the floor itself with a staple and you need to tuck the corners in like your making a bed. The idea is to end up with basically a 6 inch deep bowl that would hold water. I put the drain at the rear of the shower close to the base of the bench since I didn't want a low spot for someone to walk over. This was just a personal choice you don't need much of a slope for the floor to drain across the tile and it worked out that I had plenty of room below that spot of floor to run my drain lines.

Since there was no wall between the main bathroom floor and where it began to slope to the drain I staple the mud pan to the floor again only at the edge and used backer board on the rest of the bathroom floor and over lapped it onto the rubber by about 2 feet. They make a glue I believe for making tight corners but I'm pretty handy and got a snug fit without it. I then used backer board on the shower walls and again overlapped it on top of the rubber but not much more than about 2 inches. Again this was a personal choice cause I know backer board is supposed to be water proof but I just didn't like the idea of having a cut edge resting right on the floor where it might wick up moisture so I dunno, use your best judgement.

I intentionally sloped the floor down much deeper than the final inch and a half drop I ended up with over five feet because I wanted to be sure the rubber was well below the level of the backer board on the main floor. The drain for this is actually a double drain and the first part seals the rubber to the subfloor and allows any water making it through the tiles and mortar to go down the drain instead of causing the subfloor to get wet.

Step 3: Installing the Heated Areas

This step is pretty self explanatory and will vary with whatever product you use but basically this system uses a series of plastic strips space with slits to push the wire into. You screw them down parallel to each other and just zigzag the wires back and forth like on a loom. There is a thermostat on a lead that needs wired to the floor as well.

They also make mats in various sizes if your fortunate enough to have a rectangle you want to heat which would probobly save some time on the installation.

This wire needs embedded in the mortor and although I believe it said you could use thinset but don't quote me, since I have a mortor mixer and sand is plentiful in Florida I used a sand and portland cement mixture with fiberglass that I got from the concrete plant up the road. It's supposed to be one bag of the fiberglass to a yard of concrete but I used about twice that much. I forget precisely how I arrived at that but with my mixer it was a bag of portland cement, half a bag of fiberglass and about 40 shovels of sand. I know this is an odd mix but it sets up very firm and so far in that past year I haven't had any failures in the 14 by 26 foot kitchen floor using the same formoula but over roofing felt over 3/4 tongue and groove plywood but it also stays soft enough for a day or two that you can sand it with a brick the next day without very much effort and get a smooth surface to lay your tile on.

I started at the far back of the shower and worked my way out of the room putting about an inch and a half over the shower pan at the bottom then smoothed it so it buried the wires by about 1/8 of an inch. I ripped some strips of treated wood 5/8 of an inch thick and ran a border of it around the walls I would be cementing to leaving about a 1/4 inch gap for expansion between the strip and the wall. I used this as a form to float the cement mixture and used treated wood so I could leave them in place. I had cut some extra strips and when I did a big room like the kitchen I would use them to temporarily float out the floor then I would go back and pick the strip out of the cement and finish it with a hand trowel as best I could.

This is where the sand it with the brick the next day comes in handy, you don't need to be a perfect finsher but don't get so far ahead of yourself you let it sit for longer than a day before you take a brick to it.

Step 4: Putting Down the Tile

At this point its a simple matter of tiling the floor and walls and for some reason I cannot recall right now you need to use unsanded grout when you get that far.

I chose to use a tile that was in 2 by 2 inch squares to make it easier to do the curvy floors since I could vary the gap a tad and make subtle curves where bigger tiles would be a problem around the drain but I suppose it would still be doable.

I made sure that it dried almost a week to be safe before I wired in the thermostat and tested it. I ran a dedicated 20 amp circuit to a box in the wall about light switch high. The ends of the loop are insulated to go inside the wall up to the box and it's a simple matter of wiring it up as instructed. There is also a lead for the thermostat that gets mounted in the floor and basically the wall thermostat keeps the floor just a few degrees above whatever the room air temp is with an adjustment so you can make it very low power consuming and simply not feel cold when you walk on it with bare feet, or warm enough it's enough to have the dog want to sleep on it in the winter...

It also comes with timer so you can cycle it but since it is low heat you need to plan a few hours ahead.



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    25 Discussions

    Absolutely beautiful. Your wife is a very lucky lady to have such a considerate hubby!
    I've been wrangling with mine just to get heated floors in the bathroom, he seems to thinks it's dangerous!

    Great instructable! Unless you have a floor sensor though, and depending on where the floor heat thermostat is mounted, I would suggest setting the floor temp one or two degrees lower than the standard furnace stat as the floor stat will try to heat the room, which then is called "space heating" instead of "floor warming". The heat given off by the floor can cause the standard room stat to lose it's call for heat, thus overworking the floor heating. Though not homeowner install friendly, I recommend hydronic (water) radiant floors because of their efficiency and reliability. Also, anyone else that is considering electric radiant floors and if you have no other way, the electric radiant mat that comes in rolls 12" wide is more reliable than the strand wire method. The leads are much heavier and are much less prone to breaking during installation or after due to structure settling/movement. I'd love to do an instructable on how to install a hydronic radiant system sometime, but the documentation alone would fill volumes of books. And, if done wrong...BOOM.

    1 reply

    Its got both a floor and wall sensor and keeps it just a few degrees above room temp automatically and you can control how much warmer you want it.

    Your wonderful work could not have been more timely. I had just talked with my husband about handrails and our unfinished bathroom .Could this be done in a concrete slab floor house? The drain issue and  nocrawlspace>>>could a heating unit of water or the electric band be used around a fiberglass pre-fab shower/bath tub arrangement? Our gas heated water is so close to this un-finished bathroom.Maybe dig into the concrete slab to heat the bathroom floor .Followed by the possible fiberglass unit at the end of this bathroom floor.  (I have never tiled before, but read a lot about it.)

    Senseless,I too have been given many of life's hard hits .You inspire me to get all my Dad's shop tools up and running.That's why I gutted the garage! I thank you.

    Respectfully, quilter2

    1 reply

    The elextric strips just need like 7/16th of an inch of sand mix over them then tiled which would end up raising the floor almost an inch I bet.

    As far as the shower is concerned the easiest thing to do would be to build a stall but then that is defeating the purose of being able to get a wheel chair in there.

    You could spend some time and chip away enough to fit a trap in the floor but you'd also need a way to tie into a drain line and it might easily turn into one of those weekend projects that last for months LOL.

    The strips can be just a few inches from fiber glass unless you are trying to completely heat the room with a bigger strip than I used but the kit will tell you what kind of clearances you need.

    Tiling is fun just measure it all out before you start and try and keep your cuts on the exterior walls in case you have a wall thats not quite straight you can hide it with mouldings.

    You must be a wonderful guy to be so considerate of your spouse's needs. In the intro, it says "handicap accusable", did you mean "handicap accessible"?

    1 reply

    LOL Yes Accessible would be a better word... I hit the left side of my head a while back and make that kind of mistake a lot.

    Well, all I can say is have something there to inspire others. You did an awesome job, just love that shower!!!!

    Outstanding! Your creativity and forethought brought together something to be proud of. You must love your wife very much to perfectly meet her needs with style, beauty, and dignity. I admire your work and hope your memory continues to improve. Jerry

    1 reply

    Nice job Senseless, all your Instructables are very nice. I love them all, they have so much thought put into them. Great pictures and details by the way.

    6 replies

    Hey Thanks that means a lot. I was in pretty bad accident a while back and crushed the left side of my head so writing and remembering takes a bit of effort. I'm very fortunate I was in the habit of taking so many photos as I went because if I see it I remember. Eventually I'll make one for every step of building a house.

    Well, this is pretty amazing that you can do stuff with a damaged head, I hope you get better. Do you take the pictures yourself?

    I'm not gonna get much better it's been three years. I take pictures as a habit and in this case it was fortunate because if I see a photo from a year or three ago I can remember, so it's not like all the memories are gone they just are misplaced and I need a reminder sometimes. It's my lack of attention span that causes me the biggest problem but really I am so lucky to be here I seldom dwell on it. Of course it might be the lack of an attention span that causes me not to dwell on it.. I'll ponder that one at length if I ever think of it again.

    I tell everyone I know that writing their ideas down is important, that's kind of true even if you're not in a situation that makes it difficult to remember things -- Just having a few notes is enough to put your mind at ease that you won't forget it, and to remind you of what you were thinking in the first place. :)

    Senseless, great job. As an architect I appreciate you taking the ADA accessibility into consideration. You thought ahead about your wife's condition, even some architects fail to do that, and need the code to keep them on track. Thanks. Oh btw, we also call this type of floor, "radiant heat floor".

    wow... amazing.. time to tear up my junk shower... you are the modern day Albert Einstein, except u make sweet kick butt showers.