Lateral Dampness Through External Brick - to replace internal render or not?

as long as you re point with lime mortar and allow your building to breathe re render with lime render, at the moment all you seen to be doing is the complete apposite of what is required with your age of building. trying to seal the building up will come back and bite you big style. modern materials do not work well on old building, get yourself someone who understands old buildings & how the materials used in the construction of your building all work together to prevent dampness. good luck Alex

Repoint with lime mortar to allow building to breath and the damp to be released. Chop off old render and allow internal wall to dry. Once dried re render with a lime render and re plaster.

Knock off and re render

Sounds like you don’t need to re-point the external or take off plaster backing internally if it’s all for bubbling paint. If this is the case your problem sounds like a lack of ventilation.

You do not have to take the render off apply a coat of SBR Waterproof bonding agent Before you paint and it will be fine I hope this helps

The building was designed and built with lime mortars and plasters. any repointing and rendering should also be lime. usually hotlime but nhl depending on the area in question. re: internal. Whatever internal plaster materials & paint you choose just make sure they are natural, lime/ earth based and they will ensure moisture can move freely through the fabric. dont use anything non permeable, moisture resisting/trapping as it will cause an array of problems. And also check all your vents are not blocked air flow is crucial to old homes to keep them dry. hope that helps. James Wattle it be