Isolated DAMP issue on front elevation 1875 mid terrace (Yorkshire)

[mordzy]

Just remove the strap pointing in problem area. It may not be the cause but your need to investigate it, you could always temporary repoint to match prior to pointing correctly.

Regards the floor, even if it’s level it can cause issues especially if the outside is paved. Water can run off that surface towards the building. Ideally it should be lower. Installing a French drain/soak a way will help. If it is the same height.

Re the internals. I would add a stud wall with insulation and Vapor barrier before boarding. But that’s in addition to what you have. Old houses were just directly lime skimmed onto the wall.

What’s behind your plasterboard? If it’s doing it during the cold snap, when the external wall cools, and your heating goes on, windows shut, usual drying clothes inside etc, it could be that that water vapour is penetrating somewhere and condensing at the dew point on the cold external wall and collecting at the bottom.

If it’s dot dab plasterboard, it could be where there’s a few blobs of adhesive that’s bridging the wall and board and the water is collecting there.

 

[migmags]

Just remove the strap pointing in problem area. It may not be the cause but your need to investigate it, you could always temporary repoint to match prior to pointing correctly.

Regards the floor, even if it’s level it can cause issues especially if the outside is paved. Water can run off that surface towards the building. Ideally it should be lower. Installing a French drain/soak a way will help. If it is the same height.

Re the internals. I would add a stud wall with insulation and Vapor barrier before boarding. But that’s in addition to what you have. Old houses were just directly lime skimmed onto the wall.

What’s behind your plasterboard? If it’s doing it during the cold snap, when the external wall cools, and your heating goes on, windows shut, usual drying clothes inside etc, it could be that that water vapour is penetrating somewhere and condensing at the dew point on the cold external wall and collecting at the bottom.

If it’s dot dab plasterboard, it could be where there’s a few blobs of adhesive that’s bridging the wall and board and the water is collecting there.

"Just remove the strap pointing in problem area."
did you happen to read the rest of the thread? Does anyone have 7k to repoint and entire house?

Re the internals. I would add a stud wall with insulation and Vapor barrier before boarding. But that’s in addition to what you have. Old houses were just directly lime skimmed onto the wall.
Really? a stud wall? did you happen to look at the images and where the issue is? you want me to reduce my internal space for a bit of damp.

I agree with the final part of your response in that there may be a gap between plasterboard and external wall causing condensation in the wall - this has already been floated in previous responses.

 

[George_engineer]

You could DIY a bit of repointing to see if it improves things. Strap pointing looks poor on stonework, especially with grey portland cement.

Certainly I'd do a trial area with a plug chisel to see what condition the original lime mortar is in. If that is saturated then you will certainly need to redo the bottom 1-2m of pointing. Yes a mix of lime and cement strap pointing would look bad, but at least you'll be toward solving some of the issues.

 

[mordzy]

"Just remove the strap pointing in problem area."
did you happen to read the rest of the thread? Does anyone have 7k to repoint and entire house?

Re the internals. I would add a stud wall with insulation and Vapor barrier before boarding. But that’s in addition to what you have. Old houses were just directly lime skimmed onto the wall.
Really? a stud wall? did you happen to look at the images and where the issue is? you want me to reduce my internal space for a bit of damp.

I agree with the final part of your response in that there may be a gap between plasterboard and external wall causing condensation in the wall - this has already been floated in previous responses.

No that’s why I/George said remove in problem area only, you can always repoint back the small amount until you plan to do the full house. You ts an easy enough diy job once you’ve had a look. Might only need to be a ft squad or maybe just one stone. It does look like a very strong mix.

Yup. Vapour barrier and stud wall would eliminate a dew point for any condensation with the added bonus of insulating your house. No one wants to externally insulate an old house. That or leave a window on vent all the time. Or the old fashioned way and make some gaps between the mullions and window frame. 99% of damp issues (if that’s what it turns out to be) in old houses are from modern materials and our need to plug event draft. Added to that radiators with wet clothes on, tumble driers, showers etc etc. the water doesn’t magically disappear. It turns to vapour and condenses back to water on a cold surface.

What is the darker thick pointing on the lower stones on the wall? Runs parallel to where your virgin tv/internet goes in. Has the outside been lowered at some point? The stones below look in worse condition and wetter. Is that above or below the inside wall? Virgin gable should also go down the wall to allow for drips. It’s not a major thing but it could be channeling rain water inside.

My suggestions are there to help you find the cause of the issue. You may or may not get to the bottom of it without thorough investigations.

Hope that helps.

 

[migmags]

No that’s why I/George said remove in problem area only, you can always repoint back the small amount until you plan to do the full house. You ts an easy enough diy job once you’ve had a look. Might only need to be a ft squad or maybe just one stone. It does look like a very strong mix.

Yup. Vapour barrier and stud wall would eliminate a dew point for any condensation with the added bonus of insulating your house. No one wants to externally insulate an old house. That or leave a window on vent all the time. Or the old fashioned way and make some gaps between the mullions and window frame. 99% of damp issues (if that’s what it turns out to be) in old houses are from modern materials and our need to plug event draft. Added to that radiators with wet clothes on, tumble driers, showers etc etc. the water doesn’t magically disappear. It turns to vapour and condenses back to water on a cold surface.

What is the darker thick pointing on the lower stones on the wall? Runs parallel to where your virgin tv/internet goes in. Has the outside been lowered at some point? The stones below look in worse condition and wetter. Is that above or below the inside wall? Virgin gable should also go down the wall to allow for drips. It’s not a major thing but it could be channeling rain water inside.

My suggestions are there to help you find the cause of the issue. You may or may not get to the bottom of it without thorough investigations.

Hope that helps.

It's an EXTREMELEY strong mix - this was even remarked upon by the heritage-experienced pointing company that came to quote for repointing. Nevertheless - repointing is needed at some point, but will start with perhaps putting a dehumidifier in the nearby area to see what happens as the temp drops and then later remove the internal plaster and see what's cooking behind.

The darker pointing is a slap dashing of cement for some reason; unkown but suspected to do with when the flue was put in it may have been a patching of some kind for some reason.

But as previously mentioned; despite heavy rains the dark internal wall patch never appears - it only does so when the temp drops.

 

[mordzy]

How are you getting on?

Perhaps, if its only when its cold, there is some sort of cold bride between the external wall and the plaster. Warm humid air is condensing on or behind the plaster because of the colder wall and this is what you can see. You should be able to tell more if you remove the plaster to check its construction.

 

[migmags]

How are you getting on?

Perhaps, if its only when its cold, there is some sort of cold bride between the external wall and the plaster. Warm humid air is condensing on or behind the plaster because of the colder wall and this is what you can see. You should be able to tell more if you remove the plaster to check its construction.

Hi!
Yep it's back again - as usual and just as the weather dropped. Will be removing plaster in the new year once we're done with another section of work in the house atm.