DPC question

hexosan

I have a raft foundation externally tanked in under the base with a waterproof membrane which is also acting as my radon barrier. I was speaking with the block layer last night and he suggested using a DPC under the first course of blocks coming off the raft. Is this still necessary considering the slab is wrapped in a membrane.

Should mention this is a basement construction.

Thanks in advance.

hexosan

Any takers

Mellor

Does the tanking membrane continue up the face of the wall externally? Is the wall below ground?
If so a DPC wouldn't be doing anything so there's not much point putting one in.

hexosan

Mellor wrote: »

Does the tanking membrane continue up the face of the wall externally? Is the wall below ground?
If so a DPC wouldn't be doing anything so there's not much point putting one in.

Thanks for the reply,

Slab membrane is lapped up 250mm on the edge of the raft and the external tanking is brought down the wall and sealed to this.
The walls are all below ground.

BryanF

hexosan wrote: »

I have a raft foundation externally tanked in under the base with a waterproof membrane which is also acting as my radon barrier. I was speaking with the block layer last night and he suggested using a DPC under the first course of blocks coming off the raft. Is this still necessary considering the slab is wrapped in a membrane.

Should mention this is a basement construction.

Thanks in advance.

show us the detail

hexosan

Cleared it with engineer today no DPC needed

prewtna

i am intrigued by this. can you post a sketch of the detail without the dpc?