Electric radiant floor heat for bathroom
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I have a customer who wants electric radiant heat in her new bathroom, anyone have any experience with this? It’s going under ceramic tile or tumbled marble with 1/2″ tile backer and 3/4″ plywood subfloor under it.
Replies
It's easy, I prefer to run the wire, test them, and then put a skim coat over them so that theydon,t get in the way/cut durning the tilling. The product should come with installation instruction. I've dealt with two types of thermo control, one of which uses a sensor placed over the tile to sense the floor heat, the other that uses the room temp as a guide. The floor model is more responsive, but the wiring is more complicated, and make sure you can access the transformer ( if there is one) 'cause transformers always blow eventually. Actually I jsut fixed one last week, and the installer had tucked the trans under a cabinet where the heated floor contributed to it's short life. Make sure you install a gfci and make sure you put it somewhere where they can get to it easily, on that same install whenever the floor got wet the gfci tripped.
I'm considering this type of heating in my bathroom as well... Any suggestions on products or manufactures?
-Steve
aAround here we use Thermoflex.
I'm thinking of the same thing too. (of course this is AFTER I put my new bathroom in and discovered how cold the tiles are--I didn't know they had ELECTRIC systems that were that "mesh" type so that's why I didn't bother)
Anyway, I'm assuming I can simply tap into a 20-amp "supply"? Or does it have to be dedicated? (ie, like a jacuzzi tub motor has to be a dedicated 15-amp line)
--Kevin
If we assume that anything that is made by man will break, then a separate circuit is a good idea. It is not necessary but when something goes wrong and the heat tape shorts out, it will not take anything else out with it. It also depends on the size of your heated area and the load on the circuit. I did a large bathroom floor that required a remote contactor, several loops of heat cable, and two 20 amp circuits.
Depending on your local codes, a gfic circuit (either gfi outlet or breaker) may be required. Regardless, it is a good idea - especially if you are heating a wet shower floor. I don't like this idea - water eventually will find its way through the tile/grout and I have seen a number of shower pans replaced without replacing the whole bathroom tile floor. This would of course, kill the warm floor unless the shower floor were a separate heating circuit
I have installed several. I like the Easy heat warm floor system. It consists of a roll of wire, the thermostat, etc. I've seen the mats type - and they are faster and easier to use if you have a regular (rectangular) area to heat. Some mats allow you to cut the backer to vary the shape, but the baths I wire always seem to be irregular or curved. The E-H wire is stapled down in a back and forth 'search' pattern. You have to lay it out beforehand. It takes a little thought but gives more even coverage of the floor and is easiest to customize. It is also a stocked product here and unlike one mat system that is custom made available instantly.
One tip. Do not install the heat wires within 12 inches of the wax seal under the toilet.
NCCR:
I recently installed an electric radiant floor in my bathroom @ home and it is truly awesome! I researched a number of different products and ended up choosing the one carried by my local home center, which was "warm tiles" by easy heat. It consists of clear plastic coated eighth inch heat cables which are designed to clip into provided strapping which gets fastened to subfloor (which I chose not to use) Instead, after figuring the length which closely matched my square footage, and marking a cable layout on my floor with a sharpie, I started taping down cable with blue masking tape following my layout. You cannot cut cable so lenght must work out, so I ended up re-adjusting layout at the end of the run. When this was tacked down, and I positioned the floor sensor location, I cut shallow quarter inch slots in the existing tile floor to accomodate the thickness of the factory splice in the heat cable to terminal leads and the floor sensor so they wouldn't be sticking up (they're quarter inch) After clean up i chose to hot glue cable down to my existing tile floor which was a bit slow and tedious, but allowed me to secure cable tight to floor all over. This complete, I skim coate the entire floor with a good quality polymer fortified thinset, using the cables as screeds. I did this in a series of steps so I could use a previouly completed area as a screed for the next area. I let this dry for a few days before laying tile. Everything ended up flat and perfect. I followed the manufacturers recommendation of doing a continuity test on the cable after tack down and skim coat just to make sure no damage occured. I also resisted the temptation of turning on my system right away and allowing the thinset and grout to cure. But after hook-up to a GFIC circuit, and wired into the up-graded set-back thermostat, it heated. I could provide you with more info if you want it, as to spacing, cost, time, competitive products, etc.
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Thanks for the info. I've never seen "Easy Heat" before I have only seen the mesh types. I'll have to research it further.
I find this thread very interesting as I am also planning on using electric radiant in several areas of my new home being built! This brings up a question, is it possible to only heat certain small areas of a floor? i.e. In front of the toilet, lavs, kitchen sink and table areas, any areas where your feet will be in one place for a while. This would save a lot of electricity?
I, too, am still in the learning process with this but it sounds like it should be pretty flexible as far as areas that are heated. There is a website called warmlyyours.com that shows how to install the mesh type system. I'm going to research the Easy Heat single cable system today. I would imagine that it would take some time for the floor to feel warm because of the thermal mass of the tile but once it warms up it should stay warm for a pretty long time.
Edited 2/10/2003 11:48:18 AM ET by NCCR
To Ken also;
The floor warming systems - either mat type or cable type (the mat type is a cable woven into a backing material for ease of installation) all use a thermostat. In my experience it takes two hours or so for the floor to get up to temp (plywood subfloor, 1" plus of a mud bed or lightweight concrete self leveling goop, tile) and then the t-stat keeps it at that temperature. Of course you can heat as large or small an area as you want (within the constraints of the system you use - the mats come in several sizes and easy heat has a minimum length of cable that cannot be cut).
I would suggest that you turn the system on and leave it on for relatively long periods of time (controlled by the t-stat) rather than turn it on for a short use then turn it off. Every time the floor heats and cools it will expand and contract. I do not know what effect cycling the system from cold to warm many times would have on the floor, but I suspect that this usage might shorten the life of the grout or the bond between the tiles and the subfloor/mud bed/whatever.
Easy Heat warm tiles floor heating system. Try http://www.easyheat.com or 800 537-4732 or, 31977 US 20 East, New Carlisle, IN 46552. Good luck!
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