Solid wall buildings (stone/mass concrete) can only take so much wetting. It’s vital that you protected them where possible and they will repay you by standing upright and staying healthy.
If you notice blistering or flaking paint at low level wall areas, to the external facades, it may be that there is water impact. Water will get behind the paint through some defect and lodge there, pushing off the paint layers. Depending on the paint the moisture may not dry out but become trapped and may move inward through the building fabric. This may cause damage to interior decorations and in time, the walls and floors of your building may deteriorate.
So, what should you do? Where paint is blistering or flaking, remove it. The paint is already damaged so it’s not doing its job. Trace the water ingress back to where it entered and close this off. This may mean scraping large sections of wall to remove damaged paint layers. Allow the render to dry out and examine it to ensure that it’s not compromised. What has caused the ingress? Was it poor paintwork? Perhaps supersaturation by leaking or poorly aligned rainwater goods caused the issue? Gullies often get blocked with debris and vegetation so a bit of housework might be required here to allow them to function as they were intended.
Perhaps rainwater splashback caused by having too hard a surface abutting the wall, like a concrete driveway or footpath impacted the wall? Regardless of the cause it’s a case of using your observation skills to work out the problem. Then it will be a matter of applying the process of elimination to arrive at remediation. If you cannot work out the reason your wall is suffering water damage, talk to a professional. Help is there… use it.
If you have a solid wall building in need of some tlc and you need professional input call Brigid at Fortress Planning on 062 65566 or 087 2198801.