ceramic floor tile warming

[Les]

had several hundred foot of ceramic tile installed on an uninsulated concrete slab here in Michigan.  five zones of floor heating electric film under tile.  none of them work.  i had contractor remove several tiles that were over mat/film and he had installed them with a latex mod mortar, notched 3/8" directly on top of mat.  there is no electrical issues (all new and triple checked for continuity).  best gain I can get after 10days of operation is plus five degrees .l any ideas?

 

[BADAIR]

Les, tone generator w/probe & or IR has been my go-to & may be the ticket

tone gens are cheap & easy to use for the above average bear

[Bill Kibbel]

Multiple mats wired in series?

[Chad Fabry]

Turn on the breaker. If that's not it, by-pass the floor sensor.

[Les]

five individual circuits and t-stats.  all will come "on" and all will warm floor slightly.  these are film type and I have never used them before.  thought they would be best for existing old concrete slab installation.  I can clearly identify exact areas where the mats are with surface thermometer - gains 10-15 degrees on cold day after operating for 10 days straight.  the mats almost never shut off via temp probe and operate 99% of time with no significant gain.  

 

main question is what logic is there in a self adhering mat with a textile cover being installed with a 3/8" notch trowel and there by creating a thermal break?  will post couple photos later today.  all instructions followed by the ceramic guy and the electrical guys.  both are old time friends and great tradespeople.  

 

[John Ghent]

What is the name of your electric utility so I can buy some stock?

[Jim Katen]

22 hours ago, Les said:

main question is what logic is there in a self adhering mat with a textile cover being installed with a 3/8" notch trowel and there by creating a thermal break?

Where is the thermal break? Properly installed tiles should have zero air pockets under them, even if the thinset was installed with a 3/8" trowel.

It sounds like the mats are simply not producing enough heat. Are you sure it's not something stupid like using 120-volts on mats designed for 240-volts? Were these mats made for the North American market or the European market? 

I'd be tempted to buy another mat and fire it up without installing it to see how it behaved. 

[Les]

we have run all the mats prior to install and one we dug out from installation.  no problems there.  The photo is the only one i have right now.  it is giving me some clues now that we removed couple of tiles.  note the mortar is not making 100% contact and the fiber film over the heat film mat.  more photos later

[Jim Katen]

I don't know if it has to do with your heating problem, but those trowel marks should not be visible after the tile is installed and removed. After the tile is set, there should be 100% coverage between the tile and the thinset. 

[Marc]

9 minutes ago, Jim Katen said:

I don't know if it has to do with your heating problem, but those trowel marks should not be visible after the tile is installed and removed. After the tile is set, there should be 100% coverage between the tile and the thinset. 

Then what would be the purpose of troweling grout?  I thought troweling was about insuring contact between floor and tile at distances no further apart than the ridges left by the trowel.  The gaps between are about allow space for excess mortar to flow, since the stuff won't compress.

[Jim Katen]

2 hours ago, Marc said:

Then what would be the purpose of troweling grout?  I thought troweling was about insuring contact between floor and tile at distances no further apart than the ridges left by the trowel.  The gaps between are about allow space for excess mortar to flow, since the stuff won't compress.

You use a notched trowel to ensure that you've put down the proper amount of grout. Once you've placed the tile and pressed it in place, you should have 100% coverage with no gaps or air spaces. That's why you trowel only in 1 direction; so that the air between ridges can escape as you set the tile. As you're setting the tiles, you pull one up every so often to check. 

Here's a good video from NTCA: 

 

[Les]

The mystery was mostly solved after removal of a few tiles and seeing the mortar lines.  Jim is absolutely right with his observation about the mortar.  now I have about 1400 more foot of tile to remove.  Sounding the entire floor indicates there may be as much as 60% improperly set in mortar.

 

[Erby]

1400 foot!

That's an area about 10x140 or 20x70.

That's a LOT of tile.

What kind of building is it installed in?

 

[Les]

It is the house we bought few years ago that Concetta is insisting I finish it!  it is on 10acres and has little ponds and great gully areas.  I am in no hurry to finish it. 

 

[Jim Katen]

Will the tile guy be participating in this exercise? 

[Les]

well, he was really onboard until we started removing tiles.  now not so much.  At this time I am trying, in vain, to make him understand he can't remove tile and reset the same tile without clearing the back of tile.  also looks like we will have to replace the heat film.  stay tuned.

 

[Jim Katen]

One thing I've learned about construction mistakes: Get the demo done as fast as possible. Everyone involved prefers re-doing to un-doing. 

[Chad Fabry]

The fact that tile can be removed is proof positive that it wasn't properly installed.  One cannot remove a properly installed tile in one piece. If the tile are 12x12 or larger, the ASTM standard includes back buttering and a 1/2" trowel.

 

[Les]

i am too embarrassed to post the other photos of the removal.  embarrassed for him, not me!  I do lots of legal stuff and my kid is an atty, so you would think i would take that route, but in fact I am letting the guy off the hook a little while he wraps his head around the costs and effort this involves.   maybe I will post more photos.

 

[Jim Katen]

10 hours ago, Les said:

i am too embarrassed to post the other photos of the removal.  embarrassed for him, not me!  I do lots of legal stuff and my kid is an atty, so you would think i would take that route, but in fact I am letting the guy off the hook a little while he wraps his head around the costs and effort this involves.   maybe I will post more photos.

 

I think that anyone who has lots of experience doing legal stuff understands that the legal route is rarely the best course of action.  I've also got to stress that getting the demo done fast is supremely important. As long as the tiles are there, they're not just tiles; they're a physical symbol of a screw-up and they cause an emotional reaction every time anyone involved looks at them. After they're gone, the symbol is gone and you go back to moving forward (and healing).  

[Les]

we often advise homeowners to physically move out of house when a major build or remodel goes bad for just that reason.  They return home every day and see the problem.

 

anecdotally - likely 60% of the actions we win there is no actual money or value recovered.   it cost a lot of money to be right. 

 

[hausdok]

Hi Les,

Remember a while back when they were producing paint mixed with ceramic beads? The big selling thing was that the ceramic was supposed to slow passage of heat down through a roof in summer and slow heat loss in winter.

If that's even a real thing. Could it be dependent on the type of ceramic? Could your tile be glazed with a type of ceramic that resists thermal transfer?

I have no f*****g idea. It's just a wild guess based on some foggy s**t saved in an old file on my organic hard drive.

ONE TEAM - ONE FIGHT!!!

Mike 

[Les]

Hey Mike, the latest is the floor heat mat folks want to blame the electrician and the electrician wants to blame the tile setter.  Fact is it is 99% tile setter, possible wrong mortar and less than good tile back coverage.  the tile is porcelain and great conductor.