Newly laid porcelain floor tiles over UFH, showing lines,

[Mike the Tiler]

new porcelain floor tiles laid 4 weeks ago over new electric heating matts. Heating only connected a week ago and dark lines showing on most tiles?

possible causes? Any help/ guidance appreciated. Laid by tiler not DIY.
View attachment 114140

We had a similar issue on a job. We were brought in to investigate for insurance purposes.
1.There was no membrane put down onto the new concrete flooring and the moisture came through from the concrete into the grey adhesive and stained the tiles.
2. The tiles weren't fitted correctly many where dot and dabbed there was actually pools of moisture when we lifted the tile.
3. The tiles where laid onto concrete that was new and hadn't been allowed to cure and dry long enough.
Hope this help

 

[Ian gall]

We had a similar issue on a job. We were brought in to investigate for insurance purposes.
1.There was no membrane put down onto the new concrete flooring and the moisture came through from the concrete into the grey adhesive and stained the tiles.
2. The tiles weren't fitted correctly many where dot and dabbed there was actually pools of moisture when we lifted the tile.
3. The tiles where laid onto concrete that was new and hadn't been allowed to cure and dry long enough.
Hope this help

Thanks for that.

the kitchen was extended so part old floor part new, there was a DPM but down on new floor,. New floor was a quick set of about a week, but was left for some 6 weeks before anything went down onto it, however the lines are on tiles on both old and new floor so,fairly sure It’s not the floor. I assume that’s a reasonable assumption?

 

[Dave]

Thanks for that.

the kitchen was extended so part old floor part new, there was a DPM but down on new floor,. New floor was a quick set of about a week, but was left for some 6 weeks before anything went down onto it, however the lines are on tiles on both old and new floor so,fairly sure It’s not the floor. I assume that’s a reasonable assumption?

It’s the adhesive, sorry but simple as that.

 

[Ian gall]

It’s the adhesive, sorry but simple as that.

truth hurts! I now have to decide having new tiles ripped up with all the mess involved even more of an issue with electric UFH mats underneath or live with the lines 😱

 

[Huddersfield Tiling]

new porcelain floor tiles laid 4 weeks ago over new electric heating matts. Heating only connected a week ago and dark lines showing on most tiles?

possible causes? Any help/ guidance appreciated. Laid by tiler not DIY.
View attachment 114140

My guess is that the SLC didn't lose it's required moisture content prior to tiling, and everybody just carried own piling down more stuff and trapping more moisture...
Put a carpet over it,

 

[Ian gall]

My guess is that the SLC didn't lose it's required moisture content prior to tiling, and everybody just carried own piling down more stuff and trapping more moisture...
Put a carpet over it,

Really? Most self levelling screed is ok to cover in 24 hours or less. This was screened one morning and tiling did not start till following day and took a further 4 days to complete yet lines are on all tiles pretty much, certainly all full size tilesz
.

 

[Shaun]

new porcelain floor tiles laid 4 weeks ago over new electric heating matts. Heating only connected a week ago and dark lines showing on most tiles?

possible causes? Any help/ guidance appreciated. Laid by tiler not DIY.
View attachment 114140

Hi, that looks to me like adhesive bleed through the tile. If you look closely enough you can see the lines correspond to the trowel that was used to lay the adhesive. This is due to a couple of reasons.. 1) Grey adhesive used instead of white. 2) No back buttering of the tile prior to laying it onto the adhesive ridges. 3) The adhesive ridges have not been collapsed and that's the lines you can clearly see.

Sadly, this is something you are probably going to have to live with if you don't wish to relay the floor correcrly.

 

[Huddersfield Tiling]

Really? Most self levelling screed is ok to cover in 24 hours or less. This was screened one morning and tiling did not start till following day and took a further 4 days to complete yet lines are on all tiles pretty much, certainly all full size tilesz
.

Yeah, you're probably right, dependant on temp. Are they fully vitrified porcelain tiles?

I've changed my mind to the incorrect installation of the UFH wires and/or waiting times before it was turned on.

It could be excessive heat due to the UFH installer ordering too much mat and overlaying (not allowable) or a rapid heating of the mat/cable which has caused a premature curing of the background.

How much faith do you hold with the tiler you employed?

 

[Ian gall]

Yeah, you're probably right, dependant on temp. Are they fully vitrified porcelain tiles?

I've changed my mind to the incorrect installation of the UFH wires and/or waiting times before it was turned on.

It could be excessive heat due to the UFH installer ordering too much mat and overlaying (not allowable) or a rapid heating of the mat/cable which has caused a premature curing of the background.

How much faith do you hold with the tiler you employed?

Hi
saw the mats down and no overlapping..once UFH turned on was only set at a ro9m temp of 20 degrees, floor temp never much above 14 deg,

he was meticulous with each tile is all I can say , as not had this work done before.
not sure if vitrified as just described as porcelain, was not aware of the term vitrified until recently .

 

[Ian gall]

Hi
saw the mats down and no overlapping..once UFH turned on was only set at a ro9m temp of 20 degrees, floor temp never much above 14 deg,

he was meticulous with each tile is all I can say , as not had this work done before.
not sure if vitrified as just described as porcelain, was not aware of the term vitrified until recently .

They are not cowboys for sure , do a lot of bathrooms especially, and seemed to know what they were doing.

bit of a nightmare as not sure whether to give it some time fade, they are checking with their adhesive suppler as never had this before.