Hi there I live in a 1880 sandstone house in Cumbria. We have had prolonged rain and strong winds now for weeks. The trouble is that our pvc windows on the south east side of the house are letting in water from above. The house was repointed in lime approx 10years ago. I am not sure if it is actually the sandstone that's letting the water in rather than the windows? I re sealed all the windows this spring. And I can't see any problems there at all. Has anyone else had problems with sandstone absorbing like a sponge?
- Thread starter Rowan13
- Start date
Cubist
Member
- Messages
- 3,335
- Location
- Shropshire/Herefordshire Border
Sandstone is one of the more porous stones but it should not be that bad. What did you use to seal the perimeter boundary of the doors and windows and how was this installed? Also, have you examined and verified the mortar pointing the stonework above the frames?
Cubist
Member
- Messages
- 3,335
- Location
- Shropshire/Herefordshire Border
When were the UPVC windows installed? Was the interface between the window frame and the masonry simply packed with lime mortar?
Also, are you seeing discolouration of the sandstone on the internal faces of those walls?
Also, are you seeing discolouration of the sandstone on the internal faces of those walls?
Windows approx 10 years ago. The windows have large lengths of sandstone around all 4 edges. See photo this is an AI of my house that I done for paint colour. Around the lengths of sandstone lime pointing. Under the top floor 2 windows are discoloured now. I am literally at my wits end.
Cubist
Member
- Messages
- 3,335
- Location
- Shropshire/Herefordshire Border
Just so I'm clear on this. You are seeing rainwater inside the house and around/near the upvc sash frames. The grey panels around the windows are themselves sandstone and have been fixed to the original sandstone block walls with lime mortar. The seam/interface between the upvc frames and the panels are also filled with lime mortar. And the discolouration you are seeing is of the cills (the lowest part of the sandstone panels|) of the first floor windows. Is that correct?
Is the water you are seeing indoors appearing on the cill, the head or the sides of the windows upvc frame?
Is the water you are seeing indoors appearing on the cill, the head or the sides of the windows upvc frame?
Cubist
Member
- Messages
- 3,335
- Location
- Shropshire/Herefordshire Border
It would be wise then to check the seal around the top edge of the uppermost panels where they meet the stone block-work if you can to make sure that driven rainwater cannot get behind it there. Any such can track over considerable distances.
Silicon sealants can dry out and pull away from either or both the masonry and/or the upvc components. UPVC, like most materials can expand and contract with temperature changes - originating both outdoors and indoors. This can induce what is called differential movement at the joint lines due to the different rates of expansion and contraction of, in this case, the plastic and the stone. Such movement can be enough to break the bonds of the sealants used.
Silicon sealants can dry out and pull away from either or both the masonry and/or the upvc components. UPVC, like most materials can expand and contract with temperature changes - originating both outdoors and indoors. This can induce what is called differential movement at the joint lines due to the different rates of expansion and contraction of, in this case, the plastic and the stone. Such movement can be enough to break the bonds of the sealants used.
Jahouli
Member
- Messages
- 28
- Location
- Lincolnshire
The external stone will be less thick immediately infront of the lintels, above the window. It could be possible that constant soaking of the stone through driving rain is making it through that thinner skin of stone, and is then travelling down and around the windows. My house is limestone and west facing. When I removed failing plaster around the doors and windows I was amazed to see how far into the wall rain soaked over a wet winter, similar to the one we are having now.
This picture illustrates the structural build up I'm referring to:
I'm not sure what the solution would be if this is the issue, and I wouldn't advocate non-breathable solutions, but in my part of the country external stone was traditionally limewashed to help keep houses dry. Current fashion is to have exposed stone.
This picture illustrates the structural build up I'm referring to:
I'm not sure what the solution would be if this is the issue, and I wouldn't advocate non-breathable solutions, but in my part of the country external stone was traditionally limewashed to help keep houses dry. Current fashion is to have exposed stone.
That makes total sense. I never thought about the wall being thinner in front of the lintel. It totally goes against what I have been trying to do in that maintaining a breathable house. But I am going to apply storm dry above the windows to see if this solves it. Thanks so much for your help.
Cubist
Member
- Messages
- 3,335
- Location
- Shropshire/Herefordshire Border
Applying a sealant such as Stormseal or any other such to a sandstone wall risks trapping water in the block-work that, during the freeze-thaw cycle, produces spalling - effectively the exposed surface of the stone is effectively blown off to potentially significant depths.
Please check with other authorities here and elsewhere, you could be about to do severe harm to your home.
Please check with other authorities here and elsewhere, you could be about to do severe harm to your home.
Cubist
Member
- Messages
- 3,335
- Location
- Shropshire/Herefordshire Border
Typically I would advise packing the joint lines between window frames and the exterior masonry with either oakum or caulking cotton before applying a closing cover of lime mortar or filler. This is not an easy job or quick job though and best done in the Spring or Summer.
If you are comfortable working on a ladder though there is an emergency temporary fix you could try that is both cheap and effective. This uses a product called Plumbers Mait, available from any hardware store. This is a putty typically used to seal the joints of sanitary ware and has the advantage of never setting, remains flexible, and can be pressed into even small gaps at the joints between any type of frame and the masonry. Whilst messy to use it can be removed later when more permanent repairs can be implemented.
If you are comfortable working on a ladder though there is an emergency temporary fix you could try that is both cheap and effective. This uses a product called Plumbers Mait, available from any hardware store. This is a putty typically used to seal the joints of sanitary ware and has the advantage of never setting, remains flexible, and can be pressed into even small gaps at the joints between any type of frame and the masonry. Whilst messy to use it can be removed later when more permanent repairs can be implemented.