Kelmarsh Hall Northamptonshire
Barnwell Castle Northamptonshire
Ancient Monument Consent was required from English Heritage for the proposed work.
Abbotts Hill School near Hemel Hempstead
The Stone House, Thornby, Northamptonshire
This house is constructed from Northamptonshire stone which is quite a soft stone that can erode when in an exposed, aggressive environment.
The areas of the house that were conserved were in and around the ground floor front windows.
Stones used as lintels and window jambs had delaminated due to water ingress below the first floor and ground floor windows. Mortar joints had been washed from between the stones, creating deep voids behind the facing stones.
These deep voids were grouted using a lime based grout. Stones that were delaminating were pinned with 3mm copper dowels and then grouted with lime mortar. Epoxy resins were not used as these can create a barrier to moisture movement.
The mortar joints were quite thin, less than 5mm in places. So re-pointing had to be accurate and a lime rich mortar was used to fill joints that were 200mm deep in places. It was imperative that the joints were filled from the back to face so as to prevent any water movement within the wall.
Any repairs to stones were finished using a matching stone coloured mortar.