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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Building Questions >> I can't dry out the walls to decorate. https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1515852819 Message started by Duncan1977 on Jan 13^th, 2018, 2:13pm

Title: I can't dry out the walls to decorate.
Post by Duncan1977 on Jan 13^th, 2018, 2:13pm

I live in a 200 yr old house that has had some bad pointing that has been addressed. We have a damp patch ( 3 lights according to a damp meter) directly under the area of bad pointing.
We have had dehumidifiers going for 3 months and the level of moisture is not reducing. In the upstairs, the previous owners had put vinyl paint on the walls which was bubbling and weeping. I have stripped the walls and found distemper and old adhesive on a pink skimmed wall. What is behind the skimmed plaster, I have no idea. I am aware that the bricks can hold water if not sealed properly. What doesn't help is that we have only just had the heating fixed in the house. The previous oil boiler was 50 ish yrs old and not always working to keep the property warm.
I have had a steamer and sander on to remove the distemper and any residual wallpaper paste to remove any waterproof barriers. It doesn't want to dry out.
The room directly underneath is in a similar situation. We have not get a fully vented chimney from when it was blocked off. We have a louvre vent ready to put in if it needs it. The wall was so wet that the wallpaper was lifting off the walls as if it had just been put on. I am stripping back the paint and have found old patches of adhesive, a layer of skimmed pink plaster. Above the skirting board, the wall covering sounds hollow if you tap it and it looks to be bulging and is crumbly in texture. I am not sure if it is a powdered lime mortar or if it was just patched whilst something was still wet. It comes off in chunks with little force.
Am I looking at a strip back and replaster?

Title: Re: I can't dry out the walls to decorate.
Post by woodsmith on Jan 13^th, 2018, 4:37pm

Sounds like you need to strip back and then reassess the situation. If the wall stays damp then the moisture is coming from somewhere but finding the true source can often be difficult. If it's an outside wall then gutters are always the first thing to look at if the wall is very damp.

Title: Re: I can't dry out the walls to decorate.
Post by thescruff on Jan 13^th, 2018, 10:21pm

We're not talking about a cob house by any chance?

Title: Re: I can't dry out the walls to decorate.
Post by Duncan1977 on Jan 15^th, 2018, 9:56am

Thanks for the feedback - it is not a cob house. It used to be a cobblers back in the day.

woodsmith, we have done the gutters and cleaned them out since. We have not had much rain since trying to dry it out. I have uploaded a picture to show what the property looks like.

Title: Re: I can't dry out the walls to decorate.
Post by CWatters on Jan 15^th, 2018, 5:40pm

I think you need someone with experience to look at the outside again to try and confirm the problem.

Could still be some pointing issues. Did they replace lime mortar with cement mortar?

Single skin walls can be a problem as some bricks are remarkable porus. Solutions I've seen involve either rendering the outside or lining the walls inside with a membrane, battens and plasterboard.

Important to identify the cause before you spend any money on repairing and redecorating the inside.

Title: Re: I can't dry out the walls to decorate.
Post by londonman on Jan 15^th, 2018, 9:44pm

It's your water table or skew (depending on location..different terms). They need replacing, rotten laths replaced, tiles reset and proper lead sealing done. Your wall has been saturated for years and that is why it is so wet.

And never, never, ever put any sort of cement - either in pointing or in render - on a period property like yours. They need to breathe.

This is what you will find

https://c1.staticflickr.com/3/2889/34128965521_bec21c239f_k.jpg

Title: Re: I can't dry out the walls to decorate.
Post by Duncan1977 on Jan 16^th, 2018, 8:14am

Thank you all again for you time to look at this. I am in agreement that it is going to take some TLC and going back to basics. I will find an experienced builder to come and look at the property to try and sort out the pointing.

Without stopping the source, there is not much I can do to remove excess water - any advice so I can get my son back into his room or get a sensible head start to reduce costs for when we get a builder in.

Title: Re: I can't dry out the walls to decorate.
Post by londonman on Jan 16^th, 2018, 8:59am

Looks like I wasted my time replying and telling you what was wrong ?

But hey...you can waste your money pointlessly repointing if you want to.

Title: Re: I can't dry out the walls to decorate.
Post by woodsmith on Jan 16^th, 2018, 9:41am

I went to look at a house yesterday with what sounds like similar problems. From what I could see with binoculars, they have a few broken tiles at the end of a valley and this is letting water come through the roof onto the top of the wall. This is soaking down the wall which is very wet inside. Poor pointing can cause damp but if the wall is very wet it's normally coming off the roof.

From looking at your photo, is the damp on the right hand side of the house? If you look at the gutter it is a long way down from the tiles. When it rains I suspect rain is missing the gutter and running down the wall.

Title: Re: I can't dry out the walls to decorate.
Post by londonman on Jan 16^th, 2018, 12:08pm

woodsmith wrote on Jan 16^th, 2018, 9:41am:

.... Poor pointing can cause damp but if the wall is very wet it's normally coming off the roof.

....

Bang on the money.