bonded screed (pva)

[alex6192]

Hi guys,

I have recently replaced (about three weeks) an indoor concrete slab floor and plan to screed it this weekend.

Due to the layer of the screed (25mm) I plan to bonded it using a slurry of pva, cement and water. For extra strength im using pva as an admixture in the cement (1 part pva/1 part water).

One thing i am unsure on is whether I need to seal the surface before laying screed? Unibonds instructions on this are not very clear.

I have tested the porosity of the slab and i would say it is fairly porous.

Any advise would be great.

Alex

 

[noseall]

why, when replacing the slab, did you only allow for a 25mm screed!?

just thoroughly wet the area first, no need for pva.

don't skimp on the cement.