# Underfloor Hydronic Radiant Heating



## Loafer (Jan 7, 2004)

We've got electric baseboards in our basement and a ceramic floor and we're starting to feel the cold now the temperature has dropped (we just moved in on Sept 1st)
As it's our childs play area and our own lounge around watching movies drinking beer area we'd like to make it a bit comfortable so we're thinking about ripping up the floor and installing a radiant floor heating (we already have a rad. system in the house so I imagine to tap into that would be relatively easy).

I'm having trouble finding a radiant underfloor heating expert in Toronto though.....ideally I'd like to find a few to cross quote the whole job. As much as I'd love to do it myself I don't have the time nor the expertise to pull off such a job.

Anyone dabbled in this before....like to share your contacts and experiences ?

Thanks!


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## Dr.G. (Aug 4, 2001)

Loafer, we took out the baseboard heater in our bathroom and put in radiant floor heating. It is great, especially in the winter. If we ever redo the kitchen, this is what we are going to put in to this area. It is large, but for $2000 we would get everything needed, plus installation and new flooring.


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## imactheknife (Aug 7, 2003)

As a tile installer I know about radiant heat. You have to do it before the tile is down if you use the standard wire heat availible. THe best solution for me would be a separate hot water tank and water tubes in the floor but you have to do this when the slab is poured. I don't know of any other solutions if your floor is already down. Also the wire tile heat is more costly then baseboard heat so you really only want it on like in a bathroom for a short time. I woiuld suggest a natural gas fireplace with a blower if possible and on a thermostat instead of a ON/ OFF switch. Cheers, MArk


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## Dr.G. (Aug 4, 2001)

Loafer, I misread your posting. We have electric cables that are specifically for heating the floor. They were laid down, a coating put on top of them, and then our tiler came and laid the floor.


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## PenguinBoy (Aug 16, 2005)

I have electric radiant heat under ceramic tiles in my kitchen. It is nice to take the chill off the tiles, but I wouldn't want to use it as a primary heat source. If you have the room temperature where it needs to be from another heat source, you might want to look into an electric system. It won't be cheap for a large area, and you may need to look into some sort of insulation for the floor. Of course the existing tile will need to come up, which could be a significant undertaking in itself.

As others have pointed out, it will be difficult and costly to retrofit hot water in floor heat into a basement - so electric radiant is likely your only reasonable choice here.

Are there other things you can do to make the area more comfortable - such as rugs, cold air returns near the floor, etc?


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## MACSPECTRUM (Oct 31, 2002)

excellent thread and post as I will need to lay a new floor in my house (water damage from fire dept.) and was considering radiant floor

i currently have electric baseboards with 220 volt wiring and have a wood stove for backup / supplemental heat (we get frequent and lengthy power blackouts due to weather)

i think my current heating combo is best for me as i want to avoid another utility (natural gas) for my backup source

does anyone in ontario know if there is a minimum charge for natural gas if it isn't used at all?


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## Beej (Sep 10, 2005)

I don't think there is any special charge when not using gas, but the fixed costs would still occur (admin charge + fixed portion of delivery charge). Check the relevant utility's website (probably Union or Enbridge). Off the top of my head, I'd guess $15-$20/month. 

However, if you do get gas, it is the cheaper heating option, so you should consider a gas furnace if you're going that route anyway. This is based upon gas being available in your area and a line already existing for your road. If not, it probably gets more complicated and expensive.

If you're not implementing your wind/battery idea, and the blackouts are a real hassle, look into backup generator options.


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## MACSPECTRUM (Oct 31, 2002)

i do like the peace and quiet of electric baseboard heating but i will contact the local gas utility and find out what the non-use charges are

the electric battery backup would only be for water pump, fridge, tv, computer, lights

heat would be from wood stove

we have gas on our street but it has to be pulled to the house and that could be a problem this time of year

nonetheless, i have some homework

thanks for the info.


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## imactheknife (Aug 7, 2003)

The other nice thing is that a lot of fireplaces these days (woodburning/ natural gas/ propane) have install kits that will attach to heating ducts in your house and force air through the same ducts as your furnace. I like this idea as another means to heat but only I wood choose the Woodburing to supplement the furnace (less use of natural gas)

But guaranteed I will use tubes in the floor with a hotwater tank as this heats the whole floor evenly (no cold areas) and it heats the floors above as well (as heat rises) I don't know why in Canada that this isn't the norm on new houses. Well, it is more or less in ALberta as most houses are roughed in for floor heat. Then all you have to do is get a plumber to install the water bib and hotwater tank /gas hookup then you turn it on to your level of comfort with a thermostat.


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## kps (May 4, 2003)

As imactheknife pointed out, what you'd ideally want has to go down prior to the concrete slab. The slab would also need to be insulated with styrofoam prior to being poured. The piping is one continuous piece and can not have any splices. The system HAS to be pressure tested for leaks before the concrete is poured. Your existing water heater or boiler is probably not sufficient to handle the additional load.

Retrofitting the space would be a major undertaking and very costly. Look at other options as you'll never get your money back.

The electric (under tile) option is ok, but do not use the 'wired' mats, use the electric cable which can be run in any direction and anywhere you like. The mats can not be cut, so you may end up with areas which are not heated. These products are usually used in small areas such as bathrooms and are quite efficient as they do not draw much power, but keep in mind that you may need a separate circuit(s) at the box. It may even need to be GFI to comply with code.

That may be an option, but you'd need to tear up your existing tile. 

If you have plenty of headroom in the basement, you may consider strapping the slab, insulating, installing a 3/4" subfloor and then consider your options for the finished floor.


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## kps (May 4, 2003)

Decided to search some back issues of my Fine Homebuilding  magazines.

Came across a few interesting products:

Radiantec
Warmboard
Zurn has Canadian presence.

Macspec, consider a solar retrofit. See the Radiantec website.


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## MacDoc (Nov 3, 2001)

Gents - this is a small place - only 700 sq' or so - keep it real.


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## MACSPECTRUM (Oct 31, 2002)

768 to be exact.


from what i have read, radiant electric heating is good for small cold floors
the radiant water based system are better for total heat


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## MacDoc (Nov 3, 2001)

I suspect for that small space there is not enough gain for dollars spent tho I understand it's the comfort factor that is most important.
Then again sheepskin slippers are KISS. 

I mean damn you can heat that space with a couple of robust candles. 
*Let's see 1 rendered raccoon = how many heat calories and lumens *

I suspect windows, doors and hotwater to be the bigger issues.

I solved my cool room problem - both of us leave g5 towers on


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## Loafer (Jan 7, 2004)

some good links there kps.

From what I can tell on the warmboard website it looks like their system can be laid down ontop of an existing floor and have the tubing run through a series of foam pieces, on top of which you lay you new floor. Yes, I'd probably lose an inch or so in ceiling height but if it means a simple retrofit for this then fair enough.

I'll give 'em a call next week to see what the deal is.

Thanks for the links


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## gordguide (Jan 13, 2001)

Although the poured-in-place hot water/concrete floor (which acts as a heat sink) is the most common, you don't absolutely have to do it that way. There are systems that use a lightweight foamed concrete (or other material; there is one system that uses something else but I'm not sure what) that is laid to cover the water pipe. It's very light, despite what most people think when they hear "concrete", and meets loading for building codes.

It's what is used when you want to use water radiant systems to heat the upper floors in a home, and is also recommended for retrofitting. You lose a few inches of room height (typically 1.5"/45mm) when it's a retrofit. Check it out; I'll see if I can dig some links for you. Many are using the on-demand water heaters with radiant heat now, too (instead of a boiler or as a supplement to a boiler when retrofitting).

It's almost the standard heating method out West these days; if you get outside the city I would bet that 50% of rural new homes being built now in SK are radiant, and it's common to have the shop or garage use it if the house itself doesn't.

A guy I work with is finishing up his log home this winter, 2800 square feet, all radiant (hot water/natural gas boiler), on multiple levels.

Some people are using GeoThermal along with radiant in-floor systems as well, again, more common in rural areas out here. Free heat? Free "Air Conditioning" (summer cooling)? Why not?

There are a whole bunch of electric radiant floor systems out now; probably too many to list. Some are panels while others are cable that is laid in place. Expensive, though, and electricity isn't getting cheaper either. Still, it depends on you needs what is best.

There is a good FAQ here that outlines the things you should do to determine whether hot water radiant heating is a good idea for your particular application.


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## Loafer (Jan 7, 2004)

interesting stuff Gordguide.

After reading that I am convinced because I already have a rad. system to tap into that it would be the right solution for our basement and then over time we'd like to remodel the whole house in that way. Now......anyone know how I can get hold of a good contractor for this stuff ????


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## kps (May 4, 2003)

MACSPECTRUM said:


> 768 to be exact.
> 
> 
> from what i have read, radiant electric heating is good for small cold floors
> the radiant water based system are better for total heat


768sq/ft...even better. Perfect candidate for a Zero Energy Home.  

I'm dreaming of a day I could build something like this and give the finger to the utilities. Geo-thermal, wind and solar....


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## Deep Blue (Sep 16, 2005)

Our primary heat source is hydronic radiant heat. I restored a 100 year old heritage, wood frame house in vancouver a few years ago. Ripped out the slab in the basement and put the water pipes under the concrete of the new slab. 

Upstairs I ran the pipes between the joists and nhave had no problems with my oak hardwood strip floor.. It is the most fabulous, invisible source of heat. Simply unbeatable. 

For the few really cold days we get I also put gas fireplaces in the living rooms of the downstairs apartment and our own. That way you can quickly flick a switch and get an instant additional burst of heat. I highly recommend radiant heat - except in the bathroom where the tiles remain cold. They might need a different solution, perhaps an electric heat pad under the tile instead of a hydronic source to ensure they are warm to the touch.


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## Loafer (Jan 7, 2004)

Deep Blue,

Is there any reason you re-poured the concrete slab, would it have been possible to use the Warmboard solution over the top of the existing slab ?


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## SkyHook (Jan 23, 2001)

>


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## Deep Blue (Sep 16, 2005)

Loafer said:


> Deep Blue,
> 
> Is there any reason you re-poured the concrete slab, would it have been possible to use the Warmboard solution over the top of the existing slab ?


It might have been but I totally restored and rebuilt this house. It was an unfinished basement with a pad that looked like a family of elephants had lived on it after being poured by the elephants' one-eyed herder. It had to come out. Not only that, I gutted the entire space, lifted the house up by two feet, cut off the lower walls, reframed and lowered the house back down again. Just like a big meccano set. I then had 1100 square feet to design a two bedroom apartment in.

MacDoc: if you've got a small place why not just have two strategically positioned gas fireplaces (one at the front one at the back so the apartment can fill with heat. A fireplace looks good, belts out heat when you need it, starts quickly and can be as large and ostentatious with mantle or small and unobtrusive as you want. 

For the bathroom and kitchen use the electric pads which are grouted in under the tile for tat nice warm-under-the-toes feeling. Electric mats are ONLY useful for ambient heat - ie. warm your toes, but not the room.

The major drawback of heat pads however, from my experience, is that they are devlishly expensive.


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