Floor Levelling

[Evan]

(Please ignore the awful pictures, they are all I could find on my phone)

 

Looking for some advice on floor levelling if possible, please excuse my ignorance.

 

We have had an extension built and knocked down a few internal walls to make an large open plan area. The builder laid a concrete screed in the new extension and told us we need to put a latex self levelling compound over it before we lay the floor etc.

 

We now have uneven floors where the old house doesn't match the new house exactly, its about 15mm out in some areas, we plan on relaying the parquet blocks in the whole house so want to get it level.

 

The old house had parquet floor laid on top of concrete, my question is, do we need to install a new concrete screed in the old house and then lay a latex self leveller on top of that or can we just use a latex self leveller over the whole floor including the extension.

 

Hope this makes sense?

 

Edited January 26, 2022 by Evan
spelling

[MJNewton]

Why don't the new and old floors match up? Presumably one of them isn't perfectly flat? (Hopefully the old!)

 

If you do go down the self-levelling route then you it can go straight on the surfaces as-is as long as it's suitable for the maximum depth you required.

[markc]

Often a nightmare between old and new floors, get it right and looks great, sadly too many try butt one up against the other and it shows through the floor finish.

assuming it’s just minor level/s then a liquid compound over the whole floor will sort it.

im assuming and hoping the two slabs are dowelled together to keep them aligned

[PeterW]

Self Levelling compound comes in different flavours - some are better for bulking up areas and some are better at feathering out to nothing. If you are laying parquet then it needs to be broadly level but don’t worry too much as the glue will make up some of the gaps and your sanding will take some of the edges off. 

 

Do you have any heating in the slab or not ..??

 

When you’ve decided what you need to do, then you need to make sure the floor is primed if it’s really dusty and then get it wet through if you want it to flow. It won’t flow if the floor is dry, and you probably want 20% more water in the mix than the bags say as otherwise it barely flows.