Floor screed too wet?

[perky416]

Hi guys.

Did my first ever floor screed today on a small area about 1mx1m and 40-50mm deep.
I read that it has to be fairly dry, if you squeeze a handfull little to no water should come out. I squeezed the mix and no water came out however after trying to trowel it smooth the surface is soaking wet.
I laid it over freshly laid concrete that i i put down this morning.

Should i have let the concrete dry first?
Have i completley ballsed it up?
Should i rip the screed out now whilst its still not set or should it be ok?

Thanks

 

[bobasd]

its no big deal, easily rectified:
lift it, scrape the slab surface free of screed.
if possible, allow the concrete some days to dry.
is there a membrane under the concrete?
what will the final floor covering be?

 

[perky416]

Hey bob,

I have just gone back to it and its drying well now. Managed to get it pretty smooth.

Its the cupboard under the stairs, im putting a shoe rack and coat hanger under there as 2 big drawers. When i knocked the wall through, the gap between the bottom stair step and the wall at the back of the cupboard was never concreted, it was just a hole down to the DPM.

Ill just out down some cheao stick on vinyl tiles to finish off. I just didnt want it to go powdery if it was too wet so the tiles dont dont stick.

Recon itll be ok as its now drying ok or should it still come up?

 

[perky416]

Sorry for typos, holding a wiggling baby lol. At the end i was supposed to say Ill just put down some cheap stick on vinyl tiles

 

[bobasd]

what happened was the concrete flashed excess moisture as it dried - the moisture hit the screed and came through -
the worst possibility is that there wont be any bond between the concrete surface and the screed.
given your not going to have traffic maybe you take a chance - your call?

all the best with the little one.

 

[noseall]

the worst possibility is that there wont be any bond between the concrete surface and the screed.

The bond will actually be better than if the conc had dried.

 

[noseall]

Hi guys.

read above.

 

[bobasd]

not so - read what i said about the mix flashing ie a sheen of water forced up across the whole surface.
screeds are sometimes installed on green concrete but a DIY'er is best doing it in two separate phases.

 

[noseall]

a DIY'er is best doing it in two separate phases.

As are most people - but only for practical reasons. It would be like trying to lay on a mattress.

A screed (most cement based materials) will always adhere better to wet concrete - fact.

 

[bobasd]

the key to what i'm saying is that the concrete pour had probably not flashed before the screed was installed.

semi-dry screeds laid on a sheen of water tend to negate the purpose and meaning of semi-dry - fact.

 

[Nige F]

Sorry for typos, holding a wiggling baby lol. At the end i was supposed to say Ill just put down some cheap stick on vinyl tiles

You need to wait until the flashing is over , and the semi dry screed that has been wetted, has dried thoroughly. Any moisture or sheen will not allow the tiles to stick.

 

[perky416]

The concrete was left for a couple of hours before the screed was placed. There was no signs of any moisture on the surface of the concrete, it was stiffening up at this point. As its not a traffic area ive decided to leave it and see how it turns out, but its a lesson learned for the future.