Fixing solid wood floor to FLOW SCREED

[Roberto2019]

I have had a new flow screed put down in my extension.

It was a cementitious screed, that went down as a liquid, with a fully tanked membrane underneath. It was a couple of months ago so it is fully dry but obviously I will be checking this before putting flooring down.

The screed has a very smooth self-sealed surface - it is quite shiny, and not dusty at all.

My question, is whether I can glue a solid wood floor to this? Do I need to sand off the shiny layer?

Many thanks

 

[crazydaze]

Any idea of the manufacturer and the product that was used?

 

[Mr Chibs]

Think you will need to rough it up, I did mine the next day with a scrubbing brush. This is the laitence layer.
You might need a wire brush now. I was tiling and gave it a coat (or two) of primer G, but not sure if you need to do the same for wood floor.

Presume it was an anhydrite screed?

 

[Roberto2019]

Thanks, I believe it was Tarmac Topflow Screed C (or equivalent), which is cementitious, not anhydrite.

 

[crazydaze]

Looking at the website, you will need to test the subfloor with a protometer or Hydrometer for moisture (anything that tests with metal prongs is'nt suitable for check measuring a floor for moisture), if this checks out, you'll likely need to primer then finishing screed before installing the new wood.

I would speak to the technical services dept of the manufacturer of the screed that you plan to use (all the major manufacturers have a service) and give them the details of the base floor screed and ask for their product recommendations with which to proceed.

We had a similar issue with a Kitchen that was screeded and installed by a local Kitchen company when it came to us fitting a LVT flooring a few months later. The smooth, glassy finish raised our suspicions and the screed tested high for moisture after 7 months of being down. In short, F-Ball adhesives were able to confirm the particular screed (fast dry finishing screed not subfloor builder) would likely always show a high moisture content but with the correct pre-grit primer and self leveller over the top would be absolutely fine.