Damp wall help

[Andy1990]

Hello , I purchase my first house in march I I noticed when we had light rain I would get a damp line running down the wall I had the gutters cleaned and hoped this would cure it .
Since having heavy rain this month the walls have become worst. The house is a 1920 build with solid walls the property is rendered I'm not sure if it was rendered when built or if this was done after.
Just after any help in where to start because I've spoken to multiple builder and I've been told something different every time from needing to be re rendered or remove the render as it needs to breath.
Any help would be appreciated

 

[opps]

Photos of the exterior will help.

You may have cracks in the render allowing the ingress of water. If so those can be filled.

If you have solid 9" walls, they will eventually dry out, but because they can only dry into the house it may take quite some time. It goes without saying that if you have cracks, those need to be dealt with first.

I am a decorator, rather than a plasterer... I would imagine, from a cost point of view that the cheapest option would be to deal with the cracks and purchase a reasonable quality electric dehumidifier.

With photos, someone more knowledgeable than me should be able to help more.

 

[Andy1990]

Thank you I'll post some pictures tomorrow of the out side when it's light the render has definitely been repaired poorly before and painted there lots of hollow paint bubbles and loose render.
I have a electric dehumidifier running ATM and the wall have gone back to normal within hours but as soon as there light rain it starts again.

 

[Andy1990]

This is part of the render that broke off. The render seems to go over the damp course also! I read this could also contribute to the damp

 

[I'm not a robot]

I think more pictures of the outside would help, especially higher up and maybe stand back a bit.

 

[mrrusty]

Picture no1. You can see the damp patches are only where the dabs are, so the first clue is there - what sort of penetrating damp could possibly make the dabs show up like that?

It may well be some penetrating damp, but there is another clue - solid walls, which will be fairly cold. When it rains the air outside is 100% relative humidity. When it's nice and warm inside, your room air will absorb loads of water vapour. If you are drying clothes inside etc, the water vapour in the house will be even more.

It's quite possible those dabs are cold spots on the wall - and they may be cold enough to be below the dew point of the room air, so you will get condensation forming in the plaster. Your paint colour is making it show up.

Not saying there isn't penetrating damp, but could just as easily be partly or wholly condensation.

 

[Andy1990]

If alot of it was condensation what would be the correct fix be? Would removing the plaster and using insulatied plaster board help

 

[Andy1990]

Some better exterior pictures