Attention has now turned to the inside rooms of the building now that structural work is complete.
This has involved the wall replastering of the two river-facing rooms on the second and third floors, which had lost most of their original lime plaster finishes in the 1960s to cement and gypsum plasters. We took the opportunity to thermally upgrade the outside walls using fully breathable insulations: Calsitherm Climate Board on the second floor and Diasen Thermal Plaster on the third floor. Both were supplied by Ecological Building Systems and applied by DB Plaster - Natural Building Solutions.
In order to use these products, the cement and gypsum plasters were first removed back to the bare brick (it being particularly incompatible with gypsum). The Calsitherm board is applied using a proprietary three-phase system, with a base coat, board and plaster skim. The Diasen plaster, which is composed of pure NHL 3.5, cork, clay, diatomaceous earth and reinforcing fibres, is spray-applied directly onto the wall in a two-coat system, involving the levelling spray coat and a skim coat which can be applied the next day. Both products provide excellent thermal performance and moisture management through historic masonry walls.
This is the second floor room with Calsitherm insulation being applied. The boards are mounted on a lime-based adhesive screed, butted together, before being finished with a lime skim coat. An optional layer of mesh can be applied to provide additional stability to the top coat.
On completion, a mould was taken from the surviving original cornice profile from the second floor rear room and was used to reinstate the cornice in this room. New architectural joinery was installed, based precisely on original joinery elsewhere in the building, including shutterboxes and skirtings. The ceiling, two-thirds of which is the original lath-and-plaster ceiling, was consolidated using the 'wire-and-washer' method.
The room has now been stitched back to its original 1840s appearance with the added benefit of thermal upgrading.