DIY Doctor UK DIY Forums

I am looking at replacing my suspended timber ground floor for a concrete slab with insulation and screed. the timber floor sounds hollow and has 4" floor boards over it which move. I dont mind the fact that the whole floor will have to come upo and the disruption that goes with it.

what i would like clarrification of is....

our brickwork dpc and blockwork dpc are 150mm above outside ground level, but obviously because of the floor being suspended timber these dpc are 8" below the ffl.

if i take out the floor joists and keep the dpc as they are (not to keen on injection dpc) as long as i lay a membrane along the fllor and up the walls is this adequate to stop any damp getting in.

the slab is surrounded by a membrane and both skins of wall have a horizontal dpc 150mm above the ground level to prevent any damp rising in floods etc. as far as i can see this will be all ok but looking for reassurance.

no damp can get into the concrete slab or upto the ffl with the use of the membrane.

any advice welcome.

i am looking to do exactly the same and have been thinking about the way to do it for a while.

as far as i can see this will be sufficient, like you say the slab is surrounded by a membrane to prevent water/damp getting "in" to the concrete, and all skins have a horizontal dpc 150mm above ground level. i briefly spoke to our building inspector and he agreed with me.

the only thing that will need to be done is to fill in where the floor joists were built into the wall and replace the airbricks on the outside of the house with solid bricks.

if you have already done this please let me know how it went.