latex self levelling - not level / slow to go off

[Min]

Help, I think we have messed up. And reading lots of past posts on the subject has not made me optimistic.

Substrate is thermal aquafloor panels then heating mat. Used Febflor latex self levelling compound, mixed as per instructions with an electric whisk, in batches (one bag powder with one 5l liquid). Laid to depth of 5mm - 10mm. Work done by a bricklayer but it is now evident (reading Mattysupra's posts) he didn't really know what he was doing.

Much of the floor is fine but there are three areas for concern.

1 - in the last square metre, in front of the doorway where there will be lots of traffic, the level rises up like a low hill.

Question is - when is the best time to start attacking this. Previous posts suggest using a brick to file it down. Best to wait till it has gone off, or start ASAP?

2 - one area taking ages to go off. Despite mixing instructions the mix was much runnier. Do we just wait and hope? Sprinkle some dry stuff on top?

3 - lino layers arriving on Monday morning. Latex went down Thursday afternoon. Should we be waiting longer?

Please help. I am really bothered. So far the whole conversion (of coalbunker and shed to kitchen extension) has gone really smoothly but this has given me a sleepless night.

Thanks

Mary

 

[mattysupra]

um something is not correct. The floor should of been dry to walk on after about 8 hours max. It should be hard by 24hrs, when you sand!
Who mixed the compound? did any one put extra water to the mix? What is the use by date on the bags + liquid? Has the floor gone white and powder like?

 

[Min]

Compound mixed by hubby (sparks with lots of building experience) and the bricky.

No extra water was added.

Some of the areas are whitish, have been since they were poured. No white powder on surface. In fact whitest area is the one that's still soft and rather rubbery.

No best befere date, but batch number is dated 26th March 2008.

Tried sanding with a brick - now got a very smooth brick so switched to grinding stone which has smoothed out some of the bumps.

Lino layers now coming a week on Monday so we have time to sort things out.

 

[mattysupra]

sounds like water has been added to the mix or to much latex in mix or not mixed correct (lumps left in mix) . Really the compound should be uplifted but i guess that is out of the question with heat matting underneath! Your really going to have to leave it up to the floor fitters to see if they think it will be o.k

 

[Min]

Thanks Mattysupra. You're right. Apparently some of the bags got wet in one corner a few days beforehand. Big lumps were sifted out and smaller ones are now visible in the floor - hence ratio of latex to cement (or whatever it is) was wrong for that bit of the floor.

You must be shaking your head in dismay.

Fortunately the bit that is white and springy is slowly hardening up. Much of the floor is fine.

Guy is going to return to lay a very thin layer to take out the dips.

Do we need to prime?

Many thanks
Mary

 

[mattysupra]

i always advice to prime. PVA watered down will be o.k. It will also give the compound more strength. You need to let the compound dry out before you lay any more otherwise the compound underneath will cause the top to crush when you walk on it. Next time you waant to do your own floor smoothing try to steer away from latex and use acrylic based compound. Its alot stronger.

P.S you will need to use latex again this time tho.

 

[Min]

Thanks Matty. Really appreciate your advice.

Now got to get hubby to agree to prime the floor.