Flooring experts? Radiant floor heating Q? | GTAMotorcycle.com

Flooring experts? Radiant floor heating Q?

J

jc100

Well-known member
I’ve nearly settled on a particular product that seems to fit the bill for a bathroom reno. It’s a luxury vinyl tile product called Firmfit. It’s advertised as being more resilient than competitors and with higher heat and sunlight stability and completely waterproof. I’ve just read the installation blurb and it says that the product isn’t warrantied for use over electric radiant floor heating systems (which is what we are also having installed) but it is fine for water heated radiant floor systems. This is odd as nearly all the other luxury vinyl tile products on the market are fine with any heating systems as long as the cables are separated from the tile by thinset or some other barrier. There’s also YouTube videos for this product being heated and cooled compared to others
and

The US site mentions “works well with radiant floor heating” and doesn’t qualify that statement. It’s only on the Canadian installation instructions I see this although I can’t access the US documents for some reason, only the product website.

I’m only planning on using about 80sq ft max of this stuff so it’s not a billion dollar floor by any means but can anyone see why I can’t install it over electric radiant fooor heating?

Cheers.
 
My guess will be related to the temperature variation across the floor. Water heated floors should run at close to equilibrium temperature. Electric heated floors kick on the heater which gets damned hot, then turn it off for a while and the heat spreads and equalizes, then the process repeats. If someone made a variable heating system so it ran constantly at lower output instead of cycling at high output you would have no problems.

If you really like the floor and are planning on installing a heat spreader like thinset and aren't planning on having the floor much warmer than the air, I would say go for it.
 
The controllers have a maximum temperature of 104° F with the sensor embedded in the floor so I don't see why heat would be an issue. The hydronic (Water pipes) need a much thicker bed to cover the large diameter pipes. You also need the heater and pump.
 
GreyGhost said:
My guess will be related to the temperature variation across the floor. Water heated floors should run at close to equilibrium temperature. Electric heated floors kick on the heater which gets damned hot, then turn it off for a while and the heat spreads and equalizes, then the process repeats. If someone made a variable heating system so it ran constantly at lower output instead of cycling at high output you would have no problems.

If you really like the floor and are planning on installing a heat spreader like thinset and aren't planning on having the floor much warmer than the air, I would say go for it.
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The electric floor warming cables only run at about 2 watts per linear foot and when exposed you can barely feel the heat. A 16/2 lamp cord running at 15 amps gives off about the same amount of heat but being larger in diameter will have a higher surface temperature.

PM me. I've been in the heating cable business for 40 years.
 
greyghost answered it, warm water radiant is a fairly constant, the electric has a higher 'swing rate' which will lead to expansion and contraction with a vinyl floor product.

They don't warranty it, not because they are being unfair. Its because its a bad idea and in testing lead to product failure.
 
crankcall said:
greyghost answered it, warm water radiant is a fairly constant, the electric has a higher 'swing rate' which will lead to expansion and contraction with a vinyl floor product.

They don't warranty it, not because they are being unfair. Its because its a bad idea and in testing lead to product failure.
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Understood but the product testing says that it doesn’t expand and contract to the same degree as other competing products and most of the other competing products are fine over electric radiant heating. That’s why I’m confused. I also found that for the heating cables I’m getting there’s a controller setting for vinyl floors. It modulates the max temp but I need to see if it ramps heat up more gradually to avoid shocking the floor.
 
Sent off requests for further info to the manufacturer. More reading indicated the cables don’t really get hotter that 29C and the tolerance for the product with water heating is 27/28 C, not an issue there as I can see. Just speculation again but this tile has a slightly different locking system, and a slightly different core (limestone based), to many other tiles and it is slightly more rigid than some. It is cork backed but so is a competitor product that states right on the box that it’s fine with electric radiant floor heating. I just measured up and I only need just over 60 square feet and the heating cables are only for about half of that area or less. It’s for a small bathroom and a lot of floor area is taken up with the shower base and corner bath already. The heating cables I’m getting put in are the mat kind with already separated and spaced thin cables designed to be set into a bed of self levelling compound about 3/8” thick.

I’ll go with something else if this is no good but it’s the best match we found, the difference between this product and the next one we chose is about $3-4 per sq foot but because of the small quantity needed the cash isn’t that much of an obstacle more than matching the colours.
 
Some years ago I became a certified flooring inspector (because one of the things we manufactured was a wood underlay, and assessing warranty claims was a part of the job.
Almost all claims were bad installation, the ones that weren't were wrong product in wrong application ie; residential product in a commercial traffic area. I don't think we saw a failure in an actual flooring product that wasn't preventable. Most manufacturers , even the Chinese discount stuff is pretty well tested, used within the parameters they give you its just fine
 
jc100 said:
Sent off requests for further info to the manufacturer. More reading indicated the cables don’t really get hotter that 29C and the tolerance for the product with water heating is 27/28 C, not an issue there as I can see. Just speculation again but this tile has a slightly different locking system, and a slightly different core (limestone based), to many other tiles and it is slightly more rigid than some. It is cork backed but so is a competitor product that states right on the box that it’s fine with electric radiant floor heating. I just measured up and I only need just over 60 square feet and the heating cables are only for about half of that area or less. It’s for a small bathroom and a lot of floor area is taken up with the shower base and corner bath already. The heating cables I’m getting put in are the mat kind with already separated and spaced thin cables designed to be set into a bed of self levelling compound about 3/8” thick.

I’ll go with something else if this is no good but it’s the best match we found, the difference between this product and the next one we chose is about $3-4 per sq foot but because of the small quantity needed the cash isn’t that much of an obstacle more than matching the colours.
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Nuheat used to have the closest spacing but that was before they were taken over by a US conglomerate.

Also apparently the product doesn't have this restriction in the USA. Is the Canadian product poorer quality?

A trip across the border for 80 SF solves the problem.
 
a day late and dollar short

but I gotta agree with GG
it's the thermostatic cycling that is the issue with in floor electric heat is the problem
manu may claim to have dimensional stability during temp swings
but we know that's not a valid claim, akin to Boeing's claim that it's the same 737

water based in floor heating will have the same temp swings at the heating element
but the circulated liquid will remain at a much more consistent temp than an electric element that cycles on and off

you guys have this figured out, but I'm gonna state the obvious anyway
 
Ok. Appreciate all the help. Waiting for an off the record response from the rep tomorrow but I have a #2 and #3 choice in mind. #3 is definitely warrantied over electric radiant, #2 not sure as I can’t get warranty info online but it’s a weird product, pretty new...lay down vinyl tile..no click lock, no glue, friction backing and weight keep it in place. It’s not cheap, nearly 2x price of choice #1, nice and thick and super easy to lay (craft knife and straightedge basically). It’s used in commercial and residential settings too and rated for heavy traffic.

Now I just need to buy a shower, base, vanity, faucets.....tomorrow.
 
like couch vs armchair, it's not the length of the couch, it's the ends that cost. Middle is relatively cheap.
 
crankcall said:
how come the smallest room in the house is one of the most expensive to fixup
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Truth. I’d forgotten how much faucets can actually cost for example. The only vanity we could get that fits with our plumbing happens to be a double sink rather than the single sink we’d prefer (lower line combo unit but still $900 and that was the cheapest one), so that changed our mind on what we wanted to pay pretty quickly. I talked the wife out of the $600 that two bling faucets were going to cost us in favour of 2 similar big box store ones that cost less than half as much combined (still ceramic cartridge, lifetime warranty). One guy in a bathroom store seemed a bit miffed that I didn’t want to spend $4k on a custom cabinet.
 
Just an update. Floor is fine for over electric radiant heat IF certain instructions are followed carefully for the first use of heated floor after install. After that it’s fine. Need to increase heat no more than 5C a day for a few days after install, heat must have been off 24h before install. Not warrantied over this type of heated floor as most homeowners don’t follow the install protocols properly. Temp up to 30C is fine. I’m a happy camper.
 
jc100 said:
Just an update. Floor is fine for over electric radiant heat IF certain instructions are followed carefully for the first use of heated floor after install. After that it’s fine. Need to increase heat no more than 5C a day for a few days after install, heat must have been off 24h before install. Not warrantied over this type of heated floor as most homeowners don’t follow the install protocols properly. Temp up to 30C is fine. I’m a happy camper.
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Thats what I expected. We keep our floor at ~66. Just enough so it doesnt feel cold. My parents run their floor hot enough that the bathroom is at least 5 degrees warmer than the rest of the house.
 
GreyGhost said:
Thats what I expected. We keep our floor at ~66. Just enough so it doesnt feel cold. My parents run their floor hot enough that the bathroom is at least 5 degrees warmer than the rest of the house.
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I’m really looking forward to this reno. The bathroom is at the end of the HVAC run and never gets warm enough without an electric radiator in there. Hopefully this floor heating will be enough to get rid of the thing. Also the original shower was put in with natural slate which looked gorgeous......for a few years until the hard water made it look ******. Resealing, scrubbing etc did nothing to it and it just became a constant reminder of a bad initial choice.
 
jc100 said:
I’m really looking forward to this reno. The bathroom is at the end of the HVAC run and never gets warm enough without an electric radiator in there. Hopefully this floor heating will be enough to get rid of the thing. Also the original shower was put in with natural slate which looked gorgeous......for a few years until the hard water made it look ******. Resealing, scrubbing etc did nothing to it and it just became a constant reminder of a bad initial choice.
Click to expand...
My current controller allows you to control either the temperature of the floor or the temperature of the air in the room. A similar controller may be worthwhile for you and should let you ditch the auxiliary heater.
 
JavaFan said:
a day late and dollar short

but I gotta agree with GG
it's the thermostatic cycling that is the issue with in floor electric heat is the problem
manu may claim to have dimensional stability during temp swings
but we know that's not a valid claim, akin to Boeing's claim that it's the same 737

water based in floor heating will have the same temp swings at the heating element
but the circulated liquid will remain at a much more consistent temp than an electric element that cycles on and off

you guys have this figured out, but I'm gonna state the obvious anyway
Click to expand...

All floors have temperature differentials. Asl
GreyGhost said:
Thats what I expected. We keep our floor at ~66. Just enough so it doesnt feel cold. My parents run their floor hot enough that the bathroom is at least 5 degrees warmer than the rest of the house.
Click to expand...

Bare feet on ceramic typically feel the cold at 85°F.
 
GreyGhost said:
My current controller allows you to control either the temperature of the floor or the temperature of the air in the room. A similar controller may be worthwhile for you and should let you ditch the auxiliary heater.
Click to expand...

Be careful on the air stat.
Typically floor warming is done at 10-12 watts per square foot. Space heating is substantially higher and could result in an overly hot floor.

The worst case was the death of an elderly man in Niagara-on-the-Lake through a total screw up.

nationalpost.com

Contractor gets record $537,500 fine after senior burns to death on heated bathroom floor

The senior fell on the floor in the bathroom of his home, where Niagara Falls contractor Pro-Teck Electric had installed an in-floor heating system
nationalpost.com nationalpost.com

The contractor installed a 120 volt cable but hooked it up on 240. Controllers have a maximum setting of 104°F but the sensor was air mounted so didn't detect the floor temperature. To completely bury himself the contractor didn't take out a permit, not that an inspector would have been guaranteed to notice.

For rough guesstimates each watt per square foot give a temperature rise of 2F°. When you double the voltage you quadruple the output so 12 W/SF becomes 48 W/SF and a potential temp rise of 96F° above the ambient. With an ambient of 70° F or higher the floor was well over the scald limits.

I'm not a fan of air stats. If you need to heat a room you need to do heat loss calculations and figure a safe way to do it. Overly hot floors can damage carpets etc.
 
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