Controlling Rising Dampness
Damp proofing solutions
Rising dampness is the capillary rise of water within a wall’s masonry pores. Brick, stone and mortar are all susceptible and the degree of dampness will vary depending on the size of the pores, wall thickness and the level of the water table. It is actually the hygroscopic salts carried to the wall surface which causes visible internal problems. These nitrate, chloride and sulphate salts absorb atmospheric moisture resulting in the breakdown of decorative finishes and plasters.
A thorough survey is always crucial to establish the source of dampness. Frequently, dampness is the result of condensation or poor maintenance. If however the dampness cannot be controlled by lifestyle changes or building design adaptations, we generally recommend two routes:
- A Dryzone cream damp proof course followed by re-plastering with Stonehouse Premix No. 5 plaster and Pro-proof R additive
- A 3mm cavity drain membrane system which creates a physical barrier. This method is ideal for listed properties where the fabric of the building should not be compromised
Often the most effective treatment of controlling rising dampness is through the correct installation of a damp-proof course. Stonehouse uses the Dryzone system which is a damp proofing cream introduced at intervals into pre-drilled holes in the mortar course. It is not injected under pressure and allows the solution to slowly diffuse into the wall fabric, lining the masonry capillaries and reducing the level of moisture rise.
Rising damp in listed buildings
There are particular considerations when treating historic buildings for rising dampness. It is a priority to preserve the integrity of the building’s fabric and finishes by sympathetic repairs. Secondly any procedure has to be reversible, making it possible to return to the original fabric.
For this purpose, we recommend a flexible polypropylene membrane fixed at intervals with plugs. This provides a barrier between the old surface and the new finish while creating a void which allows the water within the wall to evaporate. It is then possible to apply plaster over the meshed membrane base following the contours of the wall or alternatively the walls can be dry-lined. This technology is also suitable for plinths below the soleplates of timber frame buildings.
The following case studies include examples of projects where we have provided remedies for rising damp. Please contact us to discover how we can help you.
Read our Rising Dampness Case Studies
Browse our case studies to see the full range of Rising Dampness projects we have undertaken for a range of clients.