Damp course position

[trevorbayliss]

When doing a cavity wall the outside floor level will determine the damp level.

Will the damp level for the internal block level be different to this external DPC ?

I am soon to install my block work and masonry joist hangers and these will be lower than the external DPC. So do i place my internal DPC below where the masonry hangers sit and so below the joists ?

 

[^woody^]

When doing a cavity wall the outside floor level will determine the damp level.

No. The floor level determines the DPC position, and is normally the same for either leaf.

 

[trevorbayliss]

Ok, is the DPC then 150mm above the internal floor level. I thought it was in reference to the external floor level and you are 150mm above this minimum. My DPC will be a bit higher now. I think it will be 3 or 4 courses above external floor level as opposed to the planned 2 courses above.

 

[^woody^]

The external ground level (it's not a floor) has nothing to do with where the DPC goes.

The DPC goes at finished floor level and the DPM is lapped onto it.

If you've got some odd ground levels, then you may need a tray or two DPCs. With some older timber floors, you may find that the floor boards are slightly higher than the DPC due to joist depths.