Once again- DPC is not the a versatile sealing material. It just prevents the rising of dampness on the first or second layer of blockwork.
On the photos above you can see a timber framed house, where DPC was used beneath the window frames. The course covered the entire horizontal joist of the stud work and caused dampness here. This
happened du to "sweating" of the timber under the non-breathable DPC. Fortunately we had to remove the DPC on the inner side of the window to ensure the proper airtight sealing of the joints