Phase 1 of this deep retrofit involves completely rebuilding the loft including installing an MVHR. Ground and first floors to follow in phase 2.
There were some very tricky details:
Foamglas pocket including around the padstone to isloate the steel beam from the structure, further complicated by having to maintain the cavity within the wall
Completed detail
The gable end was plastered in Thermactive insulating plaster and timber floor joists were hung off a steel beam to avoid timber bearing into the external masonry wall.
Detail showing the floor josits hung off the steel beam. The steel beams ends will be covered with Spacetherm to avoid condensation risk.
Pitched roof insulated with woodfibre so the whole construction is breathable (water vapour open)
A new steel bressummer beam was installed and made airtight to the celing of the pitched roof over the rear bay
Foamglas isolated the steel beam from the structure
Spacetherm was used to isolate the end of the steel bressummer beam from the abutting cavity walls
The retrurn secetion of the main roof showing floor reinforcement, Thermactive to walls, Intello AVCL over the purlin and woodfibre boards ready for installation