Hi I think I have rising damp

[stock709]

Hi all,


I’ve recently bought a property with solid sandstone walls (400–500 mm thick). The previous owner had timber studwork and plasterboard on the inside. I’ve removed these and found that the sandstone is damp at the bottom (looks like rising damp).

• The walls are bare sandstone now.
• There’s no modern damp-proof course (as expected in old stone houses).
• Neighbours tell me this house has always had some damp issues.

My questions are:

1. Would you leave the sandstone exposed or apply lime plaster for breathability?
2. Any tips for drying out the walls properly before finishing?
3. Should I do anything special at the bottom where the damp was worst?

I’m avoiding cement render or dot-and-dab because I know they can trap moisture. Just want the most breathable, long-term solution that looks good.





Thanks for any advice from those experienced with old stone buildings!

 

[Cubist]

You don't mention anything about the exterior. Is the house rendered externally of bare stone faced? Is there any evidence of a DPC and are surface ground levels below this and any internal floors? You have what appear to be suspended wooden floors internally, are there any air bricks visible outdoors?

 

[stock709]

You don't mention anything about the exterior. Is the house rendered externally of bare stone faced? Is there any evidence of a DPC and are surface ground levels below this and any internal floors? You have what appear to be suspended wooden floors internally, are there any air bricks visible outdoors?

No air bricks
Exterior bare sandstone
Can see holes drilled for chemical doc but don’t think this works on this type building
Concrete floors with 4x2 sat on visqueenwith osb board on top with kingspn
Internal floor higher than external

 

[stock709]

Also do I have to put the timber floor back down because if not il pull all of it up

 

[stock709]

Front of house outside ground is 200mm lower had to dig side

 

[stock709]

The door on the side of the house was added at a later date I have problems wit that as well there is no cavity tray but il post that later

 

[stock709]

This is the that’s been added at a later date internally also a tiled bathroom above no leaks from bathroom

 

[Cubist]

Thanks for the comprehensive feedback all of which seems to suggest that any rising damp would be limited to the first couple of courses of stonework above ground level. Are. you seeing any evidence of damp above that height?

Also, the photo of the frontage reveals what appear to be two drain exits on either side of the front door. Can you confirm what these are please but I've seen similar associated with run-off from guttering systems? Also, at ground level approximately 1-1.5 metres from the right corner the photo appears to include the top couple of inches of what may be an aperture in the stonework - can you confirm what that is please?

 

[Robola]

The recesses either side of the front door are for boot scrapers I think. The other opening would be more of a concern. Particularly as the lower wall looks like it gets road spray splashed against it, not much you can do about that other than make sure the pointing is all in good condition.

Those coping stones on the gable end don't look in very good condition. We have small parapet walls with coping stones and that wall is always a bit damp. Seems a very common problem with neighbouring properties too. Our local sandstone is very porous, I don't really know how capping a wall in an exposed location with a porous material is supposed to keep a wall dry. I did some emergency chimney repairs last winter and the adjacent coping stone was completely saturated, useless. Eventually once people have tried everything else multiple times they end up capped in lead.

 

[stock709]

Thanks for the comprehensive feedback all of which seems to suggest that any rising damp would be limited to the first couple of courses of stonework above ground level. Are. you seeing any evidence of damp above that height?

Also, the photo of the frontage reveals what appear to be two drain exits on either side of the front door. Can you confirm what these are please but I've seen similar associated with run-off from guttering systems? Also, at ground level approximately 1-1.5 metres from the right corner the photo appears to include the top couple of inches of what may be an aperture in the stonework - can you confirm what that is please?

The whole house is plasterboard so can’t see if damp else wher yet
Boot scrapers
And looks like old ventilation that is a lot lower than internal floor

 

[stock709]

Thanks for the comprehensive feedback all of which seems to suggest that any rising damp would be limited to the first couple of courses of stonework above ground level. Are. you seeing any evidence of damp above that height?

Also, the photo of the frontage reveals what appear to be two drain exits on either side of the front door. Can you confirm what these are please but I've seen similar associated with run-off from guttering systems? Also, at ground level approximately 1-1.5 metres from the right corner the photo appears to include the top couple of inches of what may be an aperture in the stonework - can you confirm what that is please?

No it’s just damp at the bottom but it has been dry for about 5 weeks

 

[Robola]

I should add regarding the coping stones that the original use of the upper floor of our local buildings was often used for drying fishing nets. They probably didn't care if the the wall was a bit damp. Now they have all been converted into modern living spaces it becomes an issue.

 

[Cubist]

It's clear that the pavement height has been increased over the years and that a sloping and busy road may have contributed to water accumulating and resting against the walls. Are those boot scrapers - thanks for the clarification, it's unusual to see two associated with just one entrance - in good order and doe water run-off from the road accumulate in them at all? That vent is rather puzzling - was there a cellar or is there any evidence of suspended wooden floors having been replaced at some point?

It's not unusual for the footings/foundations of these old places to be a trifle foot-wet and, where there is no DPC, therefore to see damp rising to a few courses above ground level. We've all been treated to quite a few weeks of very dry weather and local water tables are appreciably lower than normal which may explain your observation of less evident damp over the last few weeks.

 

[stock709]

I

It's clear that the pavement height has been increased over the years and that a sloping and busy road may have contributed to water accumulating and resting against the walls. Are those boot scrapers - thanks for the clarification, it's unusual to see two associated with just one entrance - in good order and doe water run-off from the road accumulate in them at all? That vent is rather puzzling - was there a cellar or is there any evidence of suspended wooden floors having been replaced at some point?

It's not unusual for the footings/foundations of these old places to be a trifle foot-wet and, where there is no DPC, therefore to see damp rising to a few courses above ground level. We've all been treated to quite a few weeks of very dry weather and local water tables are appreciably lower than normal which may explain your observation of less evident damp over the last few weeks.

t used to be timber floors when it was a pub
There are no modern footing think it’s just a pile of stone
I’m waiting for heavy rain cos no doubt it will get worse
Also the drain outside the front door is blocked (been reported)
I want to leave the stone on show could this be a problem
Also do I have to put the timber floor back down or lay on the concrete

 

[stock709]

This was 1983

 

[Cubist]

An old pub. Well that may explain a few things. Least of which being why there are two boot-scrapers. Theres a good chance there would have been a cellar and that all or most of the ground floors would have been wooden planking. That would also explain the vent to the front of the property and perhaps a similar vent or perhaps window at ground level on the side of the building shown in this latest picture. It's likely therefore that at some point the cellar was filled in and concrete used as a final cap and to create the then new ground floors. Depending on when that work was done a DPM may have been laid under the concrete and if so theres a possibility that damp rising through the cellar fill materials and soil below the concrete is being pushed into the walls. If a DPM was installed there may be traces of it around the perimeter of the walls. That drain needs to be dealt with - theres a good chance that the cellar, assuming there was one, would have had some provision for water drainage that would most likely empty into that drain - a blockage of that drain externally could be causing much higher water levels in the cellar infill materials which then transfers to the walls.

So long as the external faces of the stones have not been damaged through spalling or direct water erosion there should be no need to do much with them other that repairs to any failed pointing. You don't have to but re-establishing wooden floors should be readily doable but you would be wise to lay the new boards over a dedicated membrane installed directly over the concrete floors.

 

[stock709]

Won’t the newly installed dpc sweat on top of the concrete

 

[Itchinfilth]

Another typical thing for those holes next to the door in this area are holes to pour urine out of. Called "lant holes". A bucket would be placed outside and collected to be used in the processing of raw fabrics.

You could point internally in lime and see how it gets on left bare and see how you like the finished look and observe how the damp is progressing. Can always lime plaster in the future.

 

[stock709]

Another typical thing for those holes next to the door in this area are holes to pour urine out of. Called "lant holes". A bucket would be placed outside and collected to be used in the processing of raw fabrics.

You could point internally in lime and see how it gets on left bare and see how you like the finished look and observe how the damp is progressing. Can always lime plaster in the future.

Yeah but is there a way to stop the damp

 

[Cubist]

Won’t the newly installed dpc sweat on top of the concrete

Yes, but the intent is to stop that damp penetrating into the new wooden floor thus causing it to swell and buckle. In my home we have concrete floors that were installed with a DPM beneath about 40 years ago. In my view it was, and still is, ecomical and ecological madness to consider ripping it all up to install a limecrete solution - I can hear some members sucking air through their teeth over that one - and laid a secondary membrane to protect the floating hardwood floor in installed above it. Its worked really well now for the last 15 years.

Yeah but is there a way to stop the damp

That, sadly is just not possible. You can do a lot to reduce and mitigate damp but essentially its unavoidable... except through desertification of your part of the world perhaps and even that is unlikely to be an absolute solution.