Levelling 80m2 Concrete Slab (1 To 30mm)

[EViS]

We have a 80m2 concrete slab which although fairly level, does have low and high spots varying between 1 and 30mm. What's going to be the most cost effective method of levelling the entire slab? I presume a form of SLC, but what brand and type? We'll need ALOT of 20kg bags which will get expensive VERY quick .

 

[J Sid]

Any under floor heating?

 

[cam_low]

I used mapei latex trade for 850m2. I don't know what was paid as I didnt supply!

 

[Dan]

Maybe obvious answer, but it has to be asked because you haven't said, are you tiling it? or just some of it? or what?

 

[EViS]

There is no underfloor heating.

Only around 20% will be tiled, 40% solid wood as floating floor, and the remaining 40% carpeted.

 

[Dan]

Okay so some SLC isn't suitable for wood and carpet. It can't accept traffic directly. Glad I asked that then.

You might need to look at a couple of products that we don't always recommend tiling-wise because we don't need to.

Can anybody confirm this?

 

[EViS]

Oh, I always understood "cannot accept traffic directly" to mean it cannot be used as the final finish and must be covered (i.e. with a floor finish such as tile, wood, carpet, etc)?

 

[Spare Tool]

I'd be using tilemaster levelflex.. if you have the use of a laser level (if not borrow one) set that up then walk around the slab with a staff marking highs n lows on staff and floor as you go. Once you've found all your dips put a straight edge over them and draw the dips on the floor with a marker. Prime n level to a feathered edge.

 

[Dan]

Oh, I always understood "cannot accept traffic directly" to mean it cannot be used as the final finish and must be covered (i.e. with a floor finish such as tile, wood, carpet, etc)?

Afraid not.

Flooring that moves as you walk on it, ie carpet and floating wood floors, wear the surface down quite quick.

Pretty sure I'm not mixing up my technical specification sheets here. I might have to go read a bit to confirm.

 

[EViS]

I'd be using tilemaster levelflex.. if you have the use of a laser level (if not borrow one) set that up then walk around the slab with a staff marking highs n lows on staff and floor as you go. Once you've found all your dips put a straight edge over them and draw the dips on the floor with a marker. Prime n level to a feathered edge.

We've done just this and tbf a majority of the floor is within 10mm. There are only a handful of obvious dips upto 30mm max.

Sounds like a good plan with the straight edge (I was going to hand trowel the SLC about), but I think I'd prefer to 'wash' the whole floor with SLC to get it sweet.

 

[EViS]

Afraid not.

Flooring that moves as you walk on it, ie carpet and floating wood floors, wear the surface down quite quick.

Pretty sure I'm not mixing up my technical specification sheets here. I might have to go read a bit to confirm.

Well every day is a school day!

 

[Dan]

Well every day is a school day!

Double check with manufacturer or supplier or even read the bag see if that covers the subject, because I might not be correct there. Might be mixing up my reading from years ago. It's all a big mix in my mind these days.