Heated floors

[Anonymous]

I live in a typical 1980s colonial with one zone heating/cooling. I have this idea that if I heat the entire floor of my basement (the finished part) that it will warm it up nicely in the winter. Is this a legit idea? If so, what kind of flooring can go over the electric heating mats in a basement? Thoughts?

[Anonymous]

This is possible, the technology is called "radiant floor heat." Most commonly it's done with tubing that connects to radiator heat, but it can be done with electric mats that go under pretty much any kind of flooring.

People don't usually do the electric version over large areas because it costs a lot to operate, typically about three times as much as other kinds of heating.

In a basement, if the floor wasn't insulated below when it was installed you'll be sending a lot of heat into the ground, which is even less efficient.

[Anonymous]

FYI we were going to install it in our very small bathroom and it was around $1500

[Anonymous]

NP- adding to the above I have always gotten lots of resistance from contractors to do this.

[Anonymous]

If it fails do you have to pull up the whole floor? No way I would put that it.

[Anonymous]

If your basement gets water I wouldn’t do
It.

[Anonymous]

I recently remodeled my primary bathroom and it was around $2,000 for heated floors. I didn’t go for them mainly because my 10 minute shower didn’t really justify the cost (for me).

[Anonymous]

Anonymous wrote:This is possible, the technology is called "radiant floor heat." Most commonly it's done with tubing that connects to radiator heat, but it can be done with electric mats that go under pretty much any kind of flooring.

People don't usually do the electric version over large areas because it costs a lot to operate, typically about three times as much as other kinds of heating.

In a basement, if the floor wasn't insulated below when it was installed you'll be sending a lot of heat into the ground, which is even less efficient.

No. Heat rises, which is why radiant floor heating works in the first place. OP wouldn't be losing heat below if it's not insulated, though colder outside air may be seeping in. But also take into account that the ground temp underneath a basement floor would be warmer than surface air temps in winter.

[Anonymous]

OP here. Sounds like this would be a bit pricey for the whole floor. I maybe could consider it in more smaller sections, like if I know a big rug will be in one area, that doesn't need it. For the person who said the floor would have to be ripped up if it stopped working, I think you would just carry on with it not working until you want a new floor someday. Our basement doesn't get water so that would not be a concern.

[Anonymous]

Anonymous wrote:

Anonymous wrote:This is possible, the technology is called "radiant floor heat." Most commonly it's done with tubing that connects to radiator heat, but it can be done with electric mats that go under pretty much any kind of flooring.

People don't usually do the electric version over large areas because it costs a lot to operate, typically about three times as much as other kinds of heating.

In a basement, if the floor wasn't insulated below when it was installed you'll be sending a lot of heat into the ground, which is even less efficient.

No. Heat rises, which is why radiant floor heating works in the first place. OP wouldn't be losing heat below if it's not insulated, though colder outside air may be seeping in. But also take into account that the ground temp underneath a basement floor would be warmer than surface air temps in winter.

Hot air/liquid and such rise due to lower density. Heat in a solid will conduct in all directions. So if you're heating a thick basement slab with cold soil around it then you're losing heat that way.

Also, ground temp in the winter will be colder than the indoor temperature.


If you have a few inches of height to spare you can put in an inch of foam board with some plywood on top, then the heating mat plus flooring. The foam will reduce your heat loss through the slab.

[Anonymous]

Anonymous wrote:

Anonymous wrote:This is possible, the technology is called "radiant floor heat." Most commonly it's done with tubing that connects to radiator heat, but it can be done with electric mats that go under pretty much any kind of flooring.

People don't usually do the electric version over large areas because it costs a lot to operate, typically about three times as much as other kinds of heating.

In a basement, if the floor wasn't insulated below when it was installed you'll be sending a lot of heat into the ground, which is even less efficient.

No. Heat rises, which is why radiant floor heating works in the first place. OP wouldn't be losing heat below if it's not insulated, though colder outside air may be seeping in. But also take into account that the ground temp underneath a basement floor would be warmer than surface air temps in winter.

Well that's confidently wrong.

Heat moves in all directions. Modern building codes require basement floors to be insulated, and extra insulation if the floor is heated.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:This is possible, the technology is called "radiant floor heat." Most commonly it's done with tubing that connects to radiator heat, but it can be done with electric mats that go under pretty much any kind of flooring.

People don't usually do the electric version over large areas because it costs a lot to operate, typically about three times as much as other kinds of heating.

In a basement, if the floor wasn't insulated below when it was installed you'll be sending a lot of heat into the ground, which is even less efficient.

No. Heat rises, which is why radiant floor heating works in the first place. OP wouldn't be losing heat below if it's not insulated, though colder outside air may be seeping in. But also take into account that the ground temp underneath a basement floor would be warmer than surface air temps in winter.

Hot air/liquid and such rise due to lower density. Heat in a solid will conduct in all directions. So if you're heating a thick basement slab with cold soil around it then you're losing heat that way.

Also, ground temp in the winter will be colder than the indoor temperature.

If you have a few inches of height to spare you can put in an inch of foam board with some plywood on top, then the heating mat plus flooring. The foam will reduce your heat loss through the slab.

You can add a bit of insulating foam, but you're not heating a thick basement slab either way - that's not how the electric radiant floor heating works. The electric mats sit on top of the subfloor, and you are heating the flooring above it, which will in turn heat the air above that. Not much heat is lost through the slab either way, and it won't dramatically effect the temperature or efficiency. A little bit, sure, but the effect won't be noticeable.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:This is possible, the technology is called "radiant floor heat." Most commonly it's done with tubing that connects to radiator heat, but it can be done with electric mats that go under pretty much any kind of flooring.

People don't usually do the electric version over large areas because it costs a lot to operate, typically about three times as much as other kinds of heating.

In a basement, if the floor wasn't insulated below when it was installed you'll be sending a lot of heat into the ground, which is even less efficient.

No. Heat rises, which is why radiant floor heating works in the first place. OP wouldn't be losing heat below if it's not insulated, though colder outside air may be seeping in. But also take into account that the ground temp underneath a basement floor would be warmer than surface air temps in winter.

Well that's confidently wrong.

Heat moves in all directions.

Modern building codes require basement floors to be insulated, and extra insulation if the floor is heated.

I know building codes typically require ground insulation, but please show me where the building codes require additional nsulation for electric heated floors?

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:This is possible, the technology is called "radiant floor heat." Most commonly it's done with tubing that connects to radiator heat, but it can be done with electric mats that go under pretty much any kind of flooring.

People don't usually do the electric version over large areas because it costs a lot to operate, typically about three times as much as other kinds of heating.

In a basement, if the floor wasn't insulated below when it was installed you'll be sending a lot of heat into the ground, which is even less efficient.

No. Heat rises, which is why radiant floor heating works in the first place. OP wouldn't be losing heat below if it's not insulated, though colder outside air may be seeping in. But also take into account that the ground temp underneath a basement floor would be warmer than surface air temps in winter.

Hot air/liquid and such rise due to lower density. Heat in a solid will conduct in all directions. So if you're heating a thick basement slab with cold soil around it then you're losing heat that way.

Also, ground temp in the winter will be colder than the indoor temperature.

If you have a few inches of height to spare you can put in an inch of foam board with some plywood on top, then the heating mat plus flooring. The foam will reduce your heat loss through the slab.

You can add a bit of insulating foam, but you're not heating a thick basement slab either way - that's not how the electric radiant floor heating works. The electric mats sit on top of the subfloor, and you are heating the flooring above it, which will in turn heat the air above that. Not much heat is lost through the slab either way, and it won't dramatically effect the temperature or efficiency. A little bit, sure, but the effect won't be noticeable.

Heat doesn't go where you send it, it goes where it wants to go. And it wants to flow from warm to cold. So long as the floor is warmer than the ground under the house, heat will flow toward it. How much flows will be determined by the level of insulation. If all you have is concrete between the heating element and the soil underneath, you'll be sending as much heat down as up.

"A little bit, sure, but the effect won't be noticeable."

It depends what you mean by "noticeable." Will the floor be colder? Not at all. Will your energy bills be higher? Absolutely. Will you notice? Depends on what kind of person you are.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:This is possible, the technology is called "radiant floor heat." Most commonly it's done with tubing that connects to radiator heat, but it can be done with electric mats that go under pretty much any kind of flooring.

People don't usually do the electric version over large areas because it costs a lot to operate, typically about three times as much as other kinds of heating.

In a basement, if the floor wasn't insulated below when it was installed you'll be sending a lot of heat into the ground, which is even less efficient.

No. Heat rises, which is why radiant floor heating works in the first place. OP wouldn't be losing heat below if it's not insulated, though colder outside air may be seeping in. But also take into account that the ground temp underneath a basement floor would be warmer than surface air temps in winter.

Well that's confidently wrong.

Heat moves in all directions.

Modern building codes require basement floors to be insulated, and extra insulation if the floor is heated.

I know building codes typically require ground insulation, but please show me where the building codes require additional nsulation for electric heated floors?

International Residential code, Chapter 11, table N1102.1.2, note D:

"R-5 insulation shall be provided under the full slab area of a heated slab in addition to the required slab edge insulation R-Value for slabs as indicated in the table."