Concrete base

[wal1959]

Hi
I am building a lean to extension at the back of my house. There is a concrete base there but I don't know the composition other than it is at least 8" thick.

Builder wants to dig it out and start again. £££££££

Can I just lay a dpc membrane, 150mm of insulation and a new concrete and screed layer on top of the existing concrete. Accept I will need the dpc to come up the walls a bit.

Cheers

 

[freddiemercurystwin]

Sounds like a good builder.

 

[^woody^]

If the base is sound, and you have room for insulation and covering on top, then it can be left in