Concrete floor

[Bahco]

I have dug up my floor in the conservatory and am laying a new level one as the clown who laid it needs a new spirit level!

There is a bit of dust still around but will this matter and can I just wet it and then lay the new sharp sand and cement mix on top?

Thanks

 

[noseall]

There is a bit of dust still around but will this matter and can I just wet it and then lay the new sharp sand and cement mix on top?

Thanks

Of course you can, cement loves water.

 

[Bahco]

Thanks.

Chap next door told me to hoover it up and pva!

Overkill

 

[^woody^]

Dust, and any loose stuff will prevent adhesion of the screed, and should be removed.

The neighbour was probably correct

 

[Bahco]

 

[Nige F]

leave the dust..sprinkle some cement dust...wet and make a slurry.Lay screed. Old School

 

[noseall]

For the most part, water will deal with just about any 'powder' lying on the surface. You can be as diligent as you like with hoovering and stuff, but a fine layer of dust will always settle.

Use water prior to laying the muck and further damp down any areas that may dry up.

F**k the pva.

 

[Bahco]

Thats better thanks.

 

[roughcaster]

sprinkle some cement dust...wet and make a slurry.Lay screed. Old School

Nige,, that's more or less what we used to do before screeding a floor. We would wet the floor area,,, mix up a bucket of cement grout,,, pour it out and spread it around with a brush, and then start screeding. As long as the concrete oversite had a rough enough tamped/keyed surface, the screed would never lift,,,, and not a drop of PVA in sight.

Roughcaster.

 

[Bahco]

Nearly done now and looking good but another 2 questions please............

How long before I can put self levelling compound down and then tile over?

 

[dave1953]

Your new concrete will dry at 1mm per day so you know the depth and you have the drying time,not sure if latex or other self leveling compounds should be laid on un-dried concrete,it may lead to problems with your final floor finish in the future.