Hi,
We are in the process of building an extension to our house.
The builder has just screeded the floor and on the second day there are some areas that are crumbling, quite large and deep defects; one is over 70cm long 15-20cm wide and approx 5cm deep in fact it has reached the concrete foundation in places,there are several smaller bad spots as well.. It is obvious that the wrong mixture was used. Can it be repaired? How and what material must we buy? This area 30 sq meter will be tiled in the future (after suitable time has passed) we want to fix it ourselves as we no longer trust the builder to do it.
Thanks for any input.
S

What does "screeded the floor" mean ?

It sounds as if the screed was either laid too dry or has not been compacted correctly when installed.

There are products available which can be poured onto the screed to fill any voids and will increase the strength of the screed.

Either that or rip the screed up and start again. There are accelerated products like FlexiDry which added to the screed mix will have it dry in 3 days if your are behind on your project timelines.

Forgot to ask if you had walked on the screed on the sceond day as you should not traffic the screed for the first 48 hours and this could be why it is crumbling as you have damaged the integrity of the screed.