Damp stone walls

Hi Mandy Render on stone buildings often causes problems . A natural stone building has no cavity as you mentioned and relys on the structure be able to breath . The structure will seasonally absorb moisture in winter months and dry over summer . This is normal and needs the mortar ( usually lime based ) to act in the same way as the stone . Rough cast renders will let moisture in but can not release it fast enough so the water takes its next fastest course - through into your internal plaster . There are two main options 1- remover render and repoint the natural stone with a natural lime pointing . 2 - remover the render and re coat with a lime based or breathable coat . The building would need initial inspection first and the above list is not exhaustive but would be the obvious solution based on your questions. Kind regards Stefan . Seeger masonry

seegar masonary has the right solution either N.H.L. lime render if necessary providing the pointing behind has not been re pointed with cement in which case this will require re pointing in a N.H.L. mortar, stopping where the water is getting in will help, extractors in the bathroom & toilet may also help drying cloths on radiators internally is a no no to name a few other factors that may result in dampness but without looking at the issue its really impossible to say exactly what maybe the best long term solution. good luck alex

As well as the above sound advice it may also be possible to apply an external semi permiable coating externally. An example of which is "Stormdry" by Safeguard. I do also advise you have it surveyed before committing to any particular solution.