BASEMENT FINISHING COURSE VIDEO: Basement Infloor Heating & Insulation

In this video, I want to explain what I think is the best way to add radiant in-floor heating to a basement

There are several ways to do this in above-ground situations, but basements pose particular problems

mostly because you really do need to put some sort of insulation underneath the heat source

It's the only way you're going to get your system to operate economically, and it also makes

a big difference for comfort underfoot. So this is the situation. It's kind of an unusual twist

on an electric in-floor heating system that is, in my experience, the best. As far as I know

I've tried all of them. Some of them are quite disappointing, actually, in terms of how

unreliable they are and how they stop working once you have the finished floor installed. That's a big

disappointment. But what we've got going on here is a particular application of something

from a company called Schluter. It's a German company. They make floor tile accessories

ceramic tile accessories. And I'm just going to go through what we've got here. So down here

we have the concrete floor. And up here we have the tiles. And here we've got this gray wire is

actually the heating cable. So this is an electric in-floor system. And it also has some built-in

insulation in a way that I think you're going to find surprising. The insulation is this material here

This is the core of it. And it's called curdie board. A curdie board is a high-density

structural foam product. The core is foam. And then on this side

And on this side, there is a waterproof paper-like covering. And that paper covering is engineered to bond to Thinset Mortar That what you see here and that what you see here and that what you see here

Thinset mortar is the standard in the industry for securing tiles to all kinds of substrates

In this case, it's unmodified thin set. There is such a thing as modified thinset

But here's how it all works. you trowel, assuming you're starting with a flat subfloor

and I deal with that fairly extensively throughout the course, but assuming you're starting with a flat subfloor

you would trowel on a layer of thin set mortar directly on the concrete floor

and then the curdie board would go down, and then there's another layer of thin set

and then on top of that is what's called the DETRA Heat

uncoupling membrane. And this does two things. As an uncoupling membrane, what it allows is a small

amount of side-to-side expansion and contraction of the tiles relative to the substrate. So it provides

full support. The tiles are still fully supported, but they can move a little bit from side to side

And that's important because tiles expand and contract at different rates than the concrete floor

So as an uncoupling membrane, this DETRA product greatly boosts the reliability of the installation

and you can use some version of DTRA with any kind of tiling job

But in this case, it's DETRA heat, which is a particular form of this uncoupling membrane

It is made to accept heating cable that snaps in place. It's just the right size to accommodate it, and the cable snaps in

And you can it comes in on a spool you unroll it and you clip it down in a pattern that gives you complete coverage over the floor And you hook it up and test it make sure it working fine The next layer up is another coating of thin set mortar and this is the coating this is the

layer that allows you to set the tiles. So the tile goes on and everything's nestled down

together, and believe it or not, even with no firm support from wood or other materials, this

system, this situation works very well. It's very reliable. The curdie board foam is dense

enough that it can support all of this without any other help. So you have a very, a very reliable

installation because the side-to-side movement permitted by the uncoupling membrane is at work

you also have some decent insulation here too and you've done it all

in a way that reduces the ceiling height of your basement as little as possible

that's one of several reasons why radiant in floor heating is not always the best option for a basement

because you need some kind of insulation above the floor you also have to have the pipes

which take up more room, and then the tiles and whatever else goes on top

So with this sort of a situation, you've got really the best of all possible worlds

The only drawback to it is the fact that you're heating with electricity

which is the most expensive way to heat. And in the final ysis, it will always be the most expensive way to heat

because there's so many energy, so much energies lost in the generation and transmission of electricity

So it will always be at a disadvantage as far as a common. economy goes But the thing about heating your basement floor is that you really should never rely on this for heating the space just for heating the floor So that means your furnace or whatever system is heating your house now We do the bulk of the heating in the basement These wires here will only be warming up the floor

So they're nice to feel underfoot. And if you want to be even more frugal, you don't necessarily have to do this over your whole basement

You can just do it where heat is necessary. I know someone who has done this arrangement right here

just right in front of the place where they have the basement couch, so they can have warm feet while they watch a movie or in a bathroom

or maybe along the side of where a bed's going to be

or maybe in front of where the kitchen counter is going to be, places where warm feet are especially welcome

But if there's a better way of getting in-floor heating into a basement

than this, I don't know what it is. A couple more quick things before I finish up

First of all, you're going to have to choose a curty board that is of sufficient thickness

It comes in a wide range of thicknesses. I think you'd want at least one inch of curdie board

underneath your tile installation. And you could go with more if you wanted to as well. Another thing is that these wires are controlled

can be controlled by some pretty sophisticated thermostats that the Schluter company offers to go along with this system

They're programmable and there are wireless versions and all kinds of things

So you can program when the floor heat comes on to economize even further

There's just one thing you need to know about, and I don't think it's a really big issue

but with an installation like this, depending on the tile you're using, the floor can have a kind of a hollowish sound to it

It's not a big deal, but it's not going to have the same sound

as if you had applied tiles directly to a concrete floor. Sounds, it sounds hollow, but it's not, and it's secure and it's going to last a long time for you

But I just want you to know, it's pretty much the only drawback that I know of with this approach