Barn Conversion, Higham (Derbyshire) – Renovating 18th Century Barn to Residential Standards
Background
This was a classic barn conversion project. The new owners wished to renovate the barn, upgrading it to provide a high standard of residential accommodation.
The barn dates back to the late 18th Century and had previously been used for a number of agricultural purposes, including grain drying / storage and as a milking parlour. The barn was once part of a larger complex of mills, and water used for turning the water-wheels was diverted behind the barn via a man-made stream which remains to this day.
Damp & Salt Contaminated Walls (The Problem)
The walls and floors of the barn suffered from unacceptably high levels of dampness for residential accommodation. This was to be expected in a building that had originally been designed for agricultural use with no damp-proofing measures taken during construction. Furthermore, the rear wall of the barn was partially below ground level and ran close to the man-made stream described above.
The stonework was contaminated with salts (chlorides, nitrates and sulphates). This is a common problem in barn conversion projects, especially where the barn has previously been used to house animals. High levels of salt contamination are undesirable as they can cause damage to plaster or decorative finishes applied to the affected walls. Certain types of salts (known as hygroscopic or deliquescent salts) can also attract dampness from the air into the walls.
Zurich Insurance, who were providing the 10-year insurance cover for the barn conversion project, required a solution to the damp and contamination problems that would carry a GPI insurance-backed guarantee. A further stipulation was that the chosen system should not permanently deface the stonework.
The Solution
Damp-proofing and preservation specialists, Abbott Damp Proofing decided to line the walls and floor of the barn with Oldroyd studded cavity drainage membranes. This system was chosen for a number of reasons:
- Would cause minimal permanent damage to the stonework
- Allows underlying substrate to breathe
- Minimal surface preparation
- Excellent resistance to salts
- BBA-approved
The walls of the barn were lined with Oldroyd Xp Plaster Membrane. A thermal board dry lining system was then fixed to the membrane using a “dot & dab” technique. On the floor, the high profile Oldroyd Xv 20 membrane was used. Both membranes feature a pattern of studs which face the barn floor/wall, creating an air-gap which allows the underlying substrate to breathe. A slight slope to the floor slab ensures that any moisture collecting behind the membranes will be diverted to weep-holes at the front of the building.
The Completed Barn Conversion
David Prince of Abbott Damp-proofing was very pleased with the way the work progressed, commenting that, “although the job was fairly large, installing the membrane system was relatively straightforward and we were able to keep to our schedule”.