Damp Proofing Old Stone Built Houses

We have recently been surveying some older stone built properties for Allendale Estates (Lord Allendale), certain properties have been suffering with ongoing damp issues for a number of years. The properties are typical of rural Northumberland, stone built under a slate roof with cast iron rain water systems, the properties are of a considerable age and at one time would have been heated via solid fuel fires situated in the stone inglenook fireplaces. The properties originally had single glazed timber sash windows and doors, some of which are still in place to this day.

The damp areas we were asked to look at were not your typical everyday damp issues, several areas of dampness were noted up to 2m high with spots of high moisture readings all over the walls in various areas. We agreed that we would need to remove the wall plaster in certain areas to determine what was going on behind these damp patches.

Once the skim coat/ surface plaster was removed we discovered an old remedial damp proofing system had been fitted in the past, a sand and cement render had been applied up to a height of 2m high throughout the ground floors, it was up to 2-3inches thick in places. This was not allowing the walls to breath properly and also providing a cold surface for condensation to form throughout the winter months.

Old stone built properties need to be treated with respect, they do not take too well to modern building techniques, we have recommended a lime based render to be installed once the sand and cement have been removed, this will allow the walls to dry down over time and allow them to ‘breathe’. The inglenook fireplaces will also be opened up which will help with ventilation and reduce the build up of condensation throughout the winter months.