Sarah!

Just a heads up, the 40sf (2' x 20') heat mat is $519 while a spool of wire that is 35sf at 2" oc spacing is $193... You'll spend an additional $150 for a good 7 day programmable thermostat and with the wire probably $10 for the straps.

SS @ The Tile Shop

Thanks for the heads up and suggestions!!

--I did realize that the mat was more...but thought it might be worth it in a DIY install...might be just too much more to consider when trying to cut costs.
--We have all the time in the world to get this done since we've been living in this house only using one bathroom for five years...so it's nothing new. We could certainly thinset the cable or mat and then wait to cure...no problem.
--We don't need the radiant heat to heat the bathroom--it's actually the toastiest room in the house, having a nice big window with southern exposure and a big beast of a cast-iron radiator (another one of my reasons to maybe nix the idea of radiant heat).
--The exterior of the house has blown-in insulation and we do have storm windows (although the windows themselves are original and I plan to keep them that way...I LOVE the wavy glass...much to the chagrin of friends/family who think everyone should get replacement windows! Not me!)
--We have been upgrading the electrical and this bathroom was gutted down to the studs, so it will be all new wiring. Kitchen was down to the studs too, so little by little, we're changing out all the wiring. Walls are all original plaster (except new bath and some that were changed out in the kitchen).
--It's not really a "master bath," per se. The downstairs of this house has one full bath and the upstairs has one full bath--at the back of the house next to the sixth bedroom--actually as far away from the master bedroom as you could be in this big 'ole house! So it kind of has to be an "everyone" bathroom. When indoor plumbing was introduced to this house, they kept it all in the back right corner of the house--for the kitchen and up/down baths. We someday *might* make the designated nursery (a 10'X10' room off the master bedroom & the hallway) into a real master bath...but that would take running plumbing to the front of the house, which my husband thinks would be very difficult and cost-prohibitive.
--I don't think the layout of this bathroom is tricky at all--it's just an 8'X6' rectangle (not counting the tub area). The only "tricky" area is that we will not be tiling under the cast-iron radiator--it's got sort-of a painting piece of wood that it sits on, slightly higher than the adjoinging floor...maybe 2'X1'. That's the only tricky area.

:)
Sarah

One other note, be careful where you locate the edges mat. The heated area will essentially be exactly where the mat is located. The heat really doesn't travel laterally, at least not sufficiently to heat adjacent tiles.

You can literally have a foot on the floor with half of it warm, the other half cold. Not good.

You need to be very careful with the wires in the mat. You don't want to catch them with the edge of a trowel and nick the insulation. Double "not good."

Most sellers have squawk boxes that you connect to the wires while you are thinsetting and tiling. If you ding a wire, the box lets out a squeal so you can do repairs at that time instead of trying to find the ding and make the repair after you've tiled and grouted. The boxes can also be made on the cheap from parts at Radio Shack.

Our radiant heat floors are my singlemost favorite thing in our master bath. It's the sort of thing you could be oblivious to your whole life and once you experience them you never go back. A VERY worthwhile $300 investment for your bathroom. We lost power for 2 days in the ice storms a couple weeks ago, and warm-floor-withdrawal was tough! We loved it so much in our bathroom that we put it in our kitchen as well, and will be putting it in our new sunroom too.

They say it doesn't warm the room, but cold feet make you feel cold and warm feet make you feel warm. And our master bath is noticeably warmer in the mornings than our master bedroom is.

The mats are 3x the cost of the wire. The wire is simple to install...I did an entire kitchen floor myself in 4 hours. We used Warming Systems, which is $4/sq ft, plus $150 or so for the thermostat.

THANK YOU! I'm going to still look into it--I know it's going to be one of those things I regret later on. Now I just need to find somewhere else to scrimp a little...hmmm...

Oh, maybe I could ask for radiant flooring for Valentine's Day. How could he say no to that???

-sarah

You will regret if you do not do it. It is my favorite room in the whole house for that very single reason- my cats love it too. I placed wire as getting mats was too complicated and more expensive- it does require some prep and I did all my preliminary layouts on the floor couple times before I was satisfied. But it is not hard to do at all- little time and patience go a long way for DIY job. My hubby is electrical engineer so we did all wiring by ourselves but again, if you know your way about electrics even a bit, it should not be a problem- instructions are very clear and self explanatory.
Buy the cheapest thermostat On/Off- you will NEVER use any other features anyway- it does not use that much of electricity to bother with programmable.
I got my wire and thermostat from local Menards and total cost was incomparable if I went with pricier mats. I have had my bathroom for more than a year and very very pleased.

A low-cost install is possible.

Since you have the time, you'll get a roll of loose cable and place it yourself. Consider doing this: place lines of cable closer to each other near the outer wall of the bathroom. The effect is to have a heater near the cold wall.

I'd remove the radiator and be ready to try out the following three options:
a. replace it as is
b. replace it and lower its incoming HW flow to a dribble so it is useable as a bench / counter / tabletop surface.
c. not replacing it

Intensifying the heat where your incoming cold is greatest is what all heaters do anyway. This is not meant to open a cold tile / warm tile discussion.

What heat insulation do you currently have in your walls? in your floor? Now is a great time to open it all up to see, and to feel the cold coming in so you will know where to foam leaks closed.

There is no physical reason why not to run heat cables up the wall a bit, into a tile baseboard for example. Why this is not done routinely has a lot to do with numskull-proofing the average person's house during standard construction. Some people will drill holes into floors even if they know there is radiant heat in it: the risk of this happening in walls is several orders of magnitude greater.

With no thermostat, it'll be hot during gentle cold and not hot enough during extreme cold. With a smart thermostat you can oversize it a bit and have gentle heat at any temperature, counteracting the heat loss during winter which can vary by a factor of ten depending on how cold it is and how strong winds are.

Many buildings, well insulated, are heated with electric radiant floor heat only.

HTH
-david

Thanks for more help!! I asked at the local tile shop how much it would be, and they use SunTouch, so they said they'd have to fax the bathroom plan over to them to get an estimate. I asked them if they could ballpark--more or less than $500. He answered quickly, "Oh, WAY more than $500 if you truly do need 40sf of heat."

So that option is out. Warming systems seemed like an economical option. Was there anyone that had a bad experience with them??

Oh, and the radiator is definitely staying. It's one of those fancy old Victorian cast-iron radiators and all of them in the house work beautifully. Love the heat they give off, actually. And we're not doing any tile on the walls--only the thick, original baseboard is going back in on the sides.

Thanks again--just going to have to propose it to DH and print out some info/cost.

:)
Sarah

I am a licensed electrician. Some of the pre-sized mat manufacturers sell ONLY to tile distributors who sell ONLY to tile installers. After being jacked up on price by the extra middlemen, I contacted a seller on eBay of the Elektra brand. He sold me exactly what I needed for two baths - my own new house in 2003- one at 20 square feet and one at 40 square feet, best programmable thermostats, all the supplies for $600.00. My thermostats have the sensor in a conduit that is buried in the floor. Never had a sensor to fail, but replacement would take about 10 minutes if necessary. He does not now list on eBay, but here is a different seller of the same materials. I know nothing about this seller. Prices are probably higher now. These mats require careful planning and imagination for best layout for your area. My installation has been completely satisfactory.

Here is a link that might be useful: eBay