Electric Floor Heating

DEAR TIM: I’ve read about electric floor heating and wonder if it will really do the job. Growing up I lived in a home that had electric coils in the ceilings of the rooms. The house was never really comfortable so I’m skeptical of the claims of the radiant floor mat manufacturers. If they do work, is it an expensive way to heat? Can you control the temperature easily? How is it installed? Donna B., Rochester, NY

DEAR DONNA: Let’s cut to the chase. Do you like to eat toast? Have you ever burned a piece of bread in a toaster? That’s the proof you need to know that electric heating works and can work quite well.

But realize that electric heating systems made to be in a ceiling or a floor do NOT glow red or orange and cause things to catch on fire. The coils in these systems produce a heat that’s more like a warm moist towel a flight attendant gives you just before landing when you sit up near the front of the plane.

The most likely reason your childhood home was uncomfortable was that not enough heating coil was put into the house and there weren’t enough heat BTUs to offset the heat loss that was happening in cold weather. To give you an extreme example, think about how futile it would be to heat a large warehouse with a tiny campfire.

Here’s what you need to know about electric floor heating. I’m writing this column right now in my cozy warm man cave ham radio shack with it a comfortable 72 F inside the room while frost is coating everything outdoors as I look through my large picture window in front of me.

This fabric mat contains a continuous heat coil that uses frugal amounts of electricity to heat a room. © 2013 Tim Carter

There’s a wonderful electric coil floor mat under my handsome rough oak laminate floor. This heating system keeps my room warm even if the temperature outdoors drops below zero.

It works it my situation because the floor heating mat was designed for my heat loss. It can easily produce more heat than is lost through the walls, floor, ceiling and window. The same would be true for your home or your room where you might use this product.

My radiant floor electric mat came with a dandy wall thermostat that contains a tiny computer. You can program the thermostat to turn on and off depending on your schedule of when you want the room to be heated. You can override the computer and just set the temperature to be constant if you desire.

The cost to heat with electricity depends on where you live. There’s a wide range of prices people pay for electricity. The key to keeping your costs low is to invest heavily in insulation so the heat you create with the electricity slowly seeps outdoors. That’s what I did in my man cave. There’s lots and lots of insulation.

Be sure any windows and other openings are sealed well against air infiltration. Air leakage is one of the biggest enemies of any heating system. Tiny vampire air leaks that may seem innocent add up and rob you of both comfort and sweet moola - money.

Each of the electric floor heating systems works the same, but the installation may be different. You need to research exactly what’s required before you start.

In my situation, the manufacturer of the fiberglass mat that contained my heat coils required that the mat be set in wet thinset that’s used to install ceramic tile. This was easy to do.

After that step, I had to cover my mat with an additional one-quarter inch of thinset. My floor looked like a cement slab after I was done. This thinset protects the coils from damage caused by the finished flooring that lays on top of them, but it also spreads out the heat under the entire floor because the mortar conducts the heat. There are no hot or cold spots in the floor if you lay on it. It’s luxurious heat to say the least.

The most critical thing to consider when installing electric radiant floor heating mats, in my opinion, is the soundness of the sub-flooring. You don’t want the floor to flex or bend as over time this could cause the electric coils to break. If you have any doubt about this, have a conversation with the manufacturer of the electric floor mat you decide to install.

I’d read all the instructions that come with the product and do not deviate from them. Don’t assume that you know better and that what’s recommended is overkill. Realize that once this mat is installed, it’s virtually impossible to replace it without great effort and expense.

It’s very wise to read all the instructions even if you intend to have another person install the mat. If you do this, you’ll be able to make sure everything is fine and that you’ll not have issues down the road. The other benefit of doing this is that you can ask pointed questions of the contractors who are bidding your job. Don’t assume for a moment that the contractor, or sub-contractor, will know exactly how to install the electric heating mat!

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