Waterproofing completed.

The lining of the inside of the external walls with the bituminous sheeting has been completed and work started on the inner walls. The following picture shows both these aspects, along with the first stones for the chimney breast :

Note how the bituminous sheeting laps onto the floor to form the DPC for the inner wall (though curiously not under the starter blocks for the chimney).

The wall on the other side, adjacent to the underpinning of the existing house, has made even better progress :

One of the factors that slows progress with this construction is the application of the wall ties. Instead of just lying in the course work as the two skins are built, special ties are used to maintain the waterproof integrity of the bituminous membrane. As this photo shows, they are drilled, plugged and screwed into the outer wall, with the DPC protected with a grommit :

The builder also uses some silicon sealant as an additional safeguard.

I also had a successfull meeting with a new structural engineer this morning. He does not foresee a problem with re-doing the beam calculations and hopes to be able to eMail them to me either tomorrow or Monday.