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Underfloor heating problem
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As things are quiet in the world at the moment, would anyone be free to advise me on an issue that’s stressed me out with an UFH installation that has failed in my home please?
Please don’t post jokes on here about it as I’m quite down about the whole situation if I’m honest.
Would really appreciate some second opinions and help on the matter if possible please. |
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"As things are quiet in the world at the moment, would anyone be free to advise me on an issue that’s stressed me out with an UFH installation that has failed in my home please?"
is it a new install or not ?
if new was it tested per layout
before fitting, after surface fitting, after tiles went down.
the only thing after that is the heater control.
old install
electric ufh is only garanteed for so long then fails thats the problem with electric compared to water based ufh |
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"As things are quiet in the world at the moment, would anyone be free to advise me on an issue that’s stressed me out with an UFH installation that has failed in my home please?
Please don’t post jokes on here about it as I’m quite down about the whole situation if I’m honest.
Would really appreciate some second opinions and help on the matter if possible please."
What's the symptoms, facts |
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So, in a nutshell the problem is this.
120m2 of my downstairs was levelled using an approved SLC. 20mm polystyrene boards with aluminium tops stuck down. The pipes “slot” into the boards and then it’s had an approved renovation screed over the top. The idea was then to fit LVT (karndean or similar) on top for the final covering.
The fail is that alone all the board joins (1200 x 600mm boards) cracks have appeared and a lot of the you can hear a very faint cracking noise as you walk on them.
Nobody has been able to figure it out until earlier this week we cut out a small section to see what’s happening. It appears that the boards have been sprayed down (with the contact adhesive) but the polystyrene has not taken stuck to the back of the board very much at all. This explains why cracks have appeared in the 5mm SLC as there’s obviously some slight movement between the edges of the boards.
The problem is, I installed the boards and I can’t understand why the contact adhesive has stuck to the floor but not to the boards. I followed the instructions for the adhesive fully. Everything was dry, dust free and at the right temperature. I have a feeling the manufacturer of the boards and glue will just say it’s an installation issue 
Really troubled and concerned about the whole situation so wondered if anyone on here had expertise in these types of boards or experienced anything similar. Long shot I know but appreciate any relevant advice that’s possible. |
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"So the pipes heating etc are all ok. It’s more a board issue "
Exactly. Originally I thought the screen had failed but it looks like it hasn’t, it’s the face that the boards have caused the cracks to appear. |
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"So, in a nutshell the problem is this.
120m2 of my downstairs was levelled using an approved SLC. 20mm polystyrene boards with aluminium tops stuck down. The pipes “slot” into the boards and then it’s had an approved renovation screed over the top. The idea was then to fit LVT (karndean or similar) on top for the final covering.
The fail is that alone all the board joins (1200 x 600mm boards) cracks have appeared and a lot of the you can hear a very faint cracking noise as you walk on them.
Nobody has been able to figure it out until earlier this week we cut out a small section to see what’s happening. It appears that the boards have been sprayed down (with the contact adhesive) but the polystyrene has not taken stuck to the back of the board very much at all. This explains why cracks have appeared in the 5mm SLC as there’s obviously some slight movement between the edges of the boards.
The problem is, I installed the boards and I can’t understand why the contact adhesive has stuck to the floor but not to the boards. I followed the instructions for the adhesive fully. Everything was dry, dust free and at the right temperature. I have a feeling the manufacturer of the boards and glue will just say it’s an installation issue
Really troubled and concerned about the whole situation so wondered if anyone on here had expertise in these types of boards or experienced anything similar. Long shot I know but appreciate any relevant advice that’s possible."
Iv read this a few times
It makes little sense
5mm slc? cracks? Found out contact adhesive but you fitted it thus knew ?
Please clarify the exact construction depths and whether cracks are your problem or lack of adhesion? |
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"So the pipes heating etc are all ok. It’s more a board issue
Exactly. Originally I thought the screen had failed but it looks like it hasn’t, it’s the face that the boards have caused the cracks to appear."
First instinct is only 5mm slc over heat expanding polystyrene? |
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"So the pipes heating etc are all ok. It’s more a board issue
Exactly. Originally I thought the screen had failed but it looks like it hasn’t, it’s the face that the boards have caused the cracks to appear.
First instinct is only 5mm slc over heat expanding polystyrene?"
I mean only 5 mm over polystyrene
And that is subject to temp change 5mm does not sound enough |
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"did you score the back of the boards when fitting them, they normally have a sealed finish on them?  "
Interesting you say that. They don’t advise to score the back of the boards. They advise to spray the floor, leave for 60 seconds to go tacky and then apply the board with firm pressure. Thinking about it now, I’d have rather bought twice the amount of adhesive and sprayed the backs of the boards too but that’s not advised. So, I have no idea why they haven’t stuck properly. |
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"did you score the back of the boards when fitting them, they normally have a sealed finish on them?
Interesting you say that. They don’t advise to score the back of the boards. They advise to spray the floor, leave for 60 seconds to go tacky and then apply the board with firm pressure. Thinking about it now, I’d have rather bought twice the amount of adhesive and sprayed the backs of the boards too but that’s not advised. So, I have no idea why they haven’t stuck properly."
Is it the 5mm slc over the heating pipes that's cracking |
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By (user no longer on site)
over a year ago
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"did you score the back of the boards when fitting them, they normally have a sealed finish on them?
Interesting you say that. They don’t advise to score the back of the boards. They advise to spray the floor, leave for 60 seconds to go tacky and then apply the board with firm pressure. Thinking about it now, I’d have rather bought twice the amount of adhesive and sprayed the backs of the boards too but that’s not advised. So, I have no idea why they haven’t stuck properly."
not enough glue and the glue needs to sink into the board a little i would always score them but having said that i personally haven't seen them glued before normally the floor floats but if i were doing it I'd probably have put a thin ply on first |
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"did you score the back of the boards when fitting them, they normally have a sealed finish on them?
Interesting you say that. They don’t advise to score the back of the boards. They advise to spray the floor, leave for 60 seconds to go tacky and then apply the board with firm pressure. Thinking about it now, I’d have rather bought twice the amount of adhesive and sprayed the backs of the boards too but that’s not advised. So, I have no idea why they haven’t stuck properly.
Is it the 5mm slc over the heating pipes that's cracking "
The self levelling compound has cracked in straight lines along where the boards join. The SLC has to be 5mm of great and poured after priming. This has all been done. The issue seems to be that the cracks have occurred due to the fact that where the boards meet (and the SLC is cracked) the polystyrene board lifts up without much effort. Eg... they haven’t stuck correctly. |
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"did you score the back of the boards when fitting them, they normally have a sealed finish on them?
Interesting you say that. They don’t advise to score the back of the boards. They advise to spray the floor, leave for 60 seconds to go tacky and then apply the board with firm pressure. Thinking about it now, I’d have rather bought twice the amount of adhesive and sprayed the backs of the boards too but that’s not advised. So, I have no idea why they haven’t stuck properly.not enough glue and the glue needs to sink into the board a little i would always score them but having said that i personally haven't seen them glued before normally the floor floats but if i were doing it I'd probably have put a thin ply on first "
Yeah, this system is designed to stick to the sub straight directly. The contact adhesive had stuck to the floor correctly but not to the back of the board. My guess is that faster than 60 seconds the contact adhesive went off and didn’t stick to the back of the board properly. It gave the impression that is was sticking when fitting them though. It’s all really strange and really worrying. |
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"can I ask what your original floor was ?
concrete or wood floor ?"
It’s concrete which was levelled first. I wonder if the adhesive “went off” too quickly on the conference and therefore didn’t stick to the back of the polystyrene boards correctly. |
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