Micro-cracks to SLC poured on top of Wunda UFH boards

[mp1234]

Hi all,

Was looking for some advice in regards to micro-cracks appearing on the SLC on top of the Wunda rapid response system that was put down. The boards were primed twice with Mapei Eco Grip Plus before Mapei renovation screed 3240 was poured on top. The cracks appeared after 2-3 days of drying and there has been light footfall over the areas.

The subfloor is a mixture of concrete and suspended tongue and groove floorboards and plan to have 10mm porcelain tiles laid on top with either of 2 methods:
1. decoupling membrane and S1 adhesive
2. S2 adhesive only

Are the cracks anything to be worried about and which method would be best to tile on top of the floor?

 

[Guest1]

Hi all,

Was looking for some advice in regards to micro-cracks appearing on the SLC on top of the Wunda rapid response system that was put down. The boards were primed twice with Mapei Eco Grip Plus before Mapei renovation screed 3240 was poured on top. The cracks appeared after 2-3 days of drying and there has been light footfall over the areas.

The subfloor is a mixture of concrete and suspended tongue and groove floorboards and plan to have 10mm porcelain tiles laid on top with either of 2 methods:
1. decoupling membrane and S1 adhesive
2. S2 adhesive only

Are the cracks anything to be worried about and which method would be best to tile on top of the floor?

Hi.
did you resolve this issue? I’ve recently laid the WUNDA UFH , followed instructions for priming, renovation screed but the floor has fine cracks and sounds like walking on bubble wrap in some areas ..

 

[mp1234]

Hi.
did you resolve this issue? I’ve recently laid the WUNDA UFH , followed instructions for priming, renovation screed but the floor has fine cracks and sounds like walking on bubble wrap in some areas ..

Hi,

Ended up having schluter ditra matting down with S1 adhesive and then the tiles laid with S1 adhesive.

I did have a popping sound in one spot over the suspended floor but that has since disappeared since tiling. I did check around the cracks to see if the screed has bonded by tapping around them but all seemed fine.

Tiles have been down 4 weeks with no issues so far, although the underfloor heating hasn't been commissioned yet (plan on getting it sorted in the coming week) so yet to find out it the heat causes any issues. Fingers crossed there aren't any.