Hairline craks in SLC

[Rookery]

Have you switched the ufh on?

 

[vrytir]

Have you switched the ufh on?

No, I didnt

 

[Gazzer]

Did it crack before or after you walked on it and are the cracks in straight lines or squiggly ?

 

[Stu Lilley]

We supply and use this all the time and over timber Eco Prim Grip must be used,,,i did talk to the tech guys this week and Eco Prim grip gives a chemical and mechanical bond to what ever you apply it to,,,Primer G would not have been man enough to use over WPB

 

[nybor62]

throw a tarpaulin over it you wont see the cracks, :smilewinkgrin::smilewinkgrin:

 

[vrytir]

Did it crack before or after you walked on it and are the cracks in straight lines or squiggly ?

I think it cracked when I walked on it, but I am not 100% sure.
Cracks are squiggly.

 

[vrytir]

and the pictures

 

[big george]

are the cracks starting from the same point on the floor? could be a weakness at that point

 

[Ajax123]

and the pictures
View attachment 51194View attachment 51195View attachment 51196

Those are most definitely drying shrinkage cracks. Possibly the substrate has sucked the moisture out too quick, possibly it has evaporated too quick. You can repair them with a low viscosity epoxy resin but don't other until after you have run the underfloor heating through its heating cycle.

 

[DHTiling]

If it is hollow to tap , then it is goosed..