Do I need dpc for internal foundation wall

[mrbg07546]

We made a opening in a internal foundation wall. Before I floorboard the hole created (see picture) should I put some form of damp proof protection over foundation wall bricks?

 

[KenGMac]

mrbg07546, good evening.

Short answer is Yes.

Because you cannot see below the floor, it is not possible to tell if there is a DPC in place, so best course of action is to install an independent DPC.

Ken.

 

[mrbg07546]

Ok can I just use some membrane and wrap it round and secure it with some fixings? Or even just stick it to the underside of floorboard I plan to put over it?

Or could I even use some liquid damp proof?

 

[^woody^]

Why would you put DPC over it, if you are floor boarding across the gap. What exactly do you think the DPC will do?

 

[John D v2.0]

Depends if you'll rest the timber on the brisks. If so, one might be prudent given the cost, if not then it didn't matter.

 

[John D v2.0]

Although an internal wall will likely be pretty dry anyway - I discovered ours is wetter above the dpc slate than below it, because the air under the floor was keeping it dry, but above it was getting condensation!

 

[^woody^]

That wall has never had a DPC on it at that level, so why should it need one now?