Max thickness self levelling- multiple pours

[Lower]

We've had a problem with subsidence in the floors of our offices. Trees have sucked the water out of the clay under the floor and over 15 years or so in one office the floor has dropped by around 60mm one end compared to the other.

We've have an insurance contractor in who wants to use self levelling compound, but my understanding is that the compound he wants to use can only go to 50mm thick. He's claiming it can go thicker if he pours multiple layers over a 2 week period to allow it to dry in between.

Is he right or are we creating future problems if the self levelling is put down too thickly?

 

[^woody^]

Refer to the manufacturer's guidance for the specific product.

Has the slab been stabilised?

 

[Lower]

Refer to the manufacturer's guidance for the specific product.

Has the slab been stabilised?

The trees causing the subsidence have been removed and the slab monitored for further movement for 9 months. Its stopped moving.

I can find details of the max thickness per coat, but not whether multiple coats can be layered up to greater thicknesses.

 

[^woody^]

There is normally a maximum total thickness as the compound contains no-fines (stones) so is liable to crack if too thick

 

[Lower]

That's what i'd expect, but the technical data sheets are very specific in that they give a max thickness per coat, but not a total maximum thickness.

I'm looking for clarity to demonstrate whether its ok to build up the thickness in a number of coats, but the TDC's are not helpful.

 

[gonch69]

What's the minimum thickness you need flow screed can be used but the minimum it can go to is 25mm I believe

 

[Lower]

It needs to feather down to around 10mm at the other end of the room.

 

[gonch69]

Ultra Tile Fix ProLevel One Deep Fill Self Levelling Compound 20kg

Ultra Tile Fix ProLevel One Deep Fill Self Levelling Compound 20kg from Pro Tiler Tools, a leading supplier of Self Levelling Compound in the UK. Free UK delivery on most orders over £199 net, order online today.

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[Lower]

I've finally been able to get a look at a bag of the self levelling compound that the contractor has used and, despite him claiming it was good for 50+mm, the data on the bag specifies 20mm

Irrespective of that, he's put the carpet tiles back down and scribed (badly) the skirting board to fit but follow the level of the floor which is still 30mm out of level. He's also patched some large areas of blown plaster with easifil, claiming he's going to skim over the top.

He's been working for the insurance approved loss adjuster, so we had a meeting with the loss adjuster and the contractor on Friday and we've stopped work until they come back to us with a scheme of work that means they'll do a proper job, not the bodge that we've got at the moment.