Floor repair and levelling - urgent advice

[berty3000]

Hi all,

I'm in a stressful situation. Kitchen is being fitted from Monday. We removed the existing floor tiles to tee up the kitchen fitter to put some self leveller on and then do tiling, fit kitchen, etc. We took all of the tile adhesive off as well as the tiles and it seems this was a mistake as we have removed loads of material that now must be replaced but removing it has also left an area of devastation that needs sorting out. Highly cratered screed surface. Kitchen fitter looked shocked when he saw it.

Plan is to:

- fill the worst craters with sand and cement mix. Paint SBR into the bottom and sides of said craters then put the mortar mix in to surrounding level. This will raise the worst areas and reduce the amount of self leveller needed. Does this sound reasonable and is it likely to provide the stable surface required?

- kitchen fitter will return to do the self levelling tomorrow. It will need to be a type of screed that can go up to 50mm because of the state of the floor. He is proposing to put PVA down as a primer, is this a good idea or should I get something else? Also, does it matter whether we use latex or cement-type screed? Any advice?

Thanks

 

[berty3000]

Would this be good enough?

No Nonsense Cement-Based Levelling Screed 20kg - Screwfix

Order online at Screwfix.com. Easy-to-use levelling screed. Apply up to a bed depth of 50mm (3-50mm in one application). Simply add water and mix. Can be used internally on various substrates to either level or raise the height of an existing floor. Walkable in 4-6 hours. Ideal for creating a...

www.screwfix.com

Or

Setcrete Deep Base Floor Levelling Compound - 20kg | Wickes.co.uk

Setcrete Deep Base Floor Levelling Compound - 20kg

www.wickes.co.uk

 

[Deluks]

Either or, whichever one you can get hold of the quickest. Cutting it a bit fine aren't you!

 

[berty3000]

What primer would you use for the self leveller on this cement surface?

Also, would you paint SBR into the holes that the mortar would go in or mix SBR into the mortar?

 

[mikeey84]

I'd use an acrylic primer rather than SBR.

If you check out the flooring sub forum there is a sticky that talks about levelling a floor.

You may struggle to get the brands mentioned, but you can normally find versions at screwfix etc

 

[berty3000]

I'd use an acrylic primer rather than SBR.

If you check out the flooring sub forum there is a sticky that talks about levelling a floor.

You may struggle to get the brands mentioned, but you can normally find versions at screwfix etc

I've bought the stuff Mapei make - Primer G - since I've got their levelling compound. I notice that they say mix 1:1 - 1:3 with water depending on absorption of the substrate. Substrate in my case is cementy screed stuff. So how much water should I add? Doesn't give specifics on the can.

Also, it says on the instructions that the substrate has to be dry before applying the primer. Is this a must? The mortar I've put down to iron out bad craters will likely take some time to dry. Also, if they're saying you can mix water with it what difference does it make if the floor is not dry?

 

[mikeey84]

I'd say your floor is going to be pretty absorbant, so I'd mix 3-1.

I imagine it needs to be dry so it actually soaks in, and doesn't sit on the surface

 

[berty3000]

Thanks mate.

Could the priming be done the night before the self leveller goes on or is it best for them to be closer together (like drying time of the primer?)

 

[mikeey84]

As long as the primer is dry, I don't think it matters.

It may take longer than you think, so I'd do it the night before