Concrete floor repair and levelling

[francd1]

Hi,

I have just taken up some floor tiles in my conservatory and it appears the concrete base is pretty poor in places. Basically the concrete has eroded and I'm left with big patches of sand and gravel.

I've dug up the worst bits and left the rest of the base which seems pretty solid. My intention was just to level the floor out using a self levelling compound and then lay engineered wood flooring.

My question is, can I just repair the holes in the floor with cement and then level as originally intended. If so, how clean do the areas for repair need to be? The cement will be going on polystyrene blocks which are already down.

Cheers

Dave

 

[^woody^]

You need to make screed, not just use cement. 3 parts screed sand 1 part cement.

If there is any loose stuff there then it will all eventually break up.

If the existing screed is less than 50mm then you may end up having to replace the whole lot, or it will happen again in the future