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

[migmags]

I'll try keep it as brief as possible as I could go on on..

I'm having an internal damp issue on the front internal wall (north facing). See pictures of internal and external. House built in 1875. Yorkshire stone build.

Damp ONLY occurs in winter, coincidentally when turning the heating on twice a day - the tide line and wall up to it appears "wetter" and darker but not wet.

Initially I suspected the flue (which passes through the affect wall), this was checked and no issues found. We have a sub-level tanked out living room below ground.
I also suspected the condensate pipe was just stuck into the ground with no soakaway, this is still a possibility BUT I placed the condensate pipe in a bucket for week to check, the damp was still there.

I've now had 7 damp people, and a plumber come round, all with meters and all citing rising damp, penetrating damp, ripping plaster off, injecting a DPC course etc.. I've deleted all their numbers. I'm still none the wiser.

 

[Notch7]

I presume its a solid wall, not cavity?

so the damp are is between the door and the window -have you checked they are getting ingress through the sides. Do they have vertical dpcs? -I think this is unlikely as usually damp ingress would be adjacent to the opening bottom 2/3rds

the stone step would appear to be higher than the wall DPC -could rain water be pooling on the step and running back?


the plaster is now stained so you will have to rip it off anyway as you will never stop the stain even if the damp issue is resolved, in which case you can fit a tanking barrier of some sort before replastering -modern bonding plaster soaks up moisture like a sponge, so it needs keeping away from damp at all times

it might be worth speaking to safeguard for advice -they are damp specialist suppliers. They might suggest drybase or similar

Drybase Damp-Proof Coating Range

When it is not possible to protect building materials and interior surfaces from the sources of dampness, like rain penetration or rising damp, it is often beneficial to use a damp-proof membrane or covering to halt its progress. This can protect other vulnerable building materials and create a...

www.safeguardeurope.com

 

[migmags]

I presume its a solid wall, not cavity?

so the damp are is between the door and the window -have you checked they are getting ingress through the sides. Do they have vertical dpcs? -I think this is unlikely as usually damp ingress would be adjacent to the opening bottom 2/3rds

the stone step would appear to be higher than the wall DPC -could rain water be pooling on the step and running back?


the plaster is now stained so you will have to rip it off anyway as you will never stop the stain even if the damp issue is resolved, in which case you can fit a tanking barrier of some sort before replastering -modern bonding plaster soaks up moisture like a sponge, so it needs keeping away from damp at all times

it might be worth speaking to safeguard for advice -they are damp specialist suppliers. They might suggest drybase or similar

Drybase Damp-Proof Coating Range

When it is not possible to protect building materials and interior surfaces from the sources of dampness, like rain penetration or rising damp, it is often beneficial to use a damp-proof membrane or covering to halt its progress. This can protect other vulnerable building materials and create a...

www.safeguardeurope.com

Hi and thanks for your reply.

It's a solid wall, but I believe from what I've been told it may be a rubble filled "cavity".

As mentioned - this only seems to aggravate in the winter - it can rain for days and there's no sign of damp - which leads me to conclude that it's something to do with condensation - perhaps interstitial or other.

I agree with ripping plaster off, and it will also give us further clues once it's off.

I am vehemently against any company who simply want to "inject" rubbish into my walls, this is not the house for - I appreciate there's a time and place for DPC injections but for the most part it's a con; and without annoying anyone who is for it, there's not amount of convincing that will change my mind. This requires a thorough pinpointing of where it's coming, and I've recently been suggested to use an independent damp surveyor to avoid being ripped off (again) - however, they don't come cheap.

 

[Deleted member 174758]

It's a solid wall, but I believe from what I've been told it may be a rubble filled "cavity".

If it's a terraced house it's unlikely to be rubble infill - by 1875 that was normally only used on bigger buildings like banks with a wall thickness of 1m or more (not mills, which being taller generally required solid masonry for strength). If your window boards are 200mm to 300mm deep your walls are just as likely or to be either solid stone or cavity (generally stone outside skin with brick inside skin from about the time your building was erected). So if your inner skin is brick, you more than likely have a cavity wall, although the cavity will probably be a lot narrower than that in a modern cavity wall. I live just over the border, in a stone terraced house with a brick inner skin built in 1881, and this was a stone quarrying area (the stone in our house came about 300 yards from the quarry entrance), hence some familiarity with this type of building

I am vehemently against any company who simply want to "inject" rubbish into my walls, this is not the house for - I appreciate there's a time and place for DPC injections but for the most part it's a con; and without annoying anyone who is for it, there's not amount of convincing that will change my mind.

I've looked at your wall, but I don't see signs of a DPC. If there were one, at the age of your building it would be something like a double layer of slate, but from what I've seen slate DPCs are not that common in older stone terraces in Lancashire and West Yorkshire, and if you don't have a DPC with a sandstone wall you'll get damp at the bottoms of the walls - just like you have. With narrow cavities there is also the chance that mortar has fallen down the cavity and that also brings the possibility of moisture from the outer skin bridging to the inner skin, which is another reason you might have damp in the plaster at the bottom of the wall. Obviously you also need to look at other issues such as defective or even non-existent soakaways, damaged or missing timber troughings and damaged downpipes.

You have it in your mind that injection isn't the way to go, but the bottoms of your walls are soaking wet through, and that isn't being caused by condensation - it's either water coming through the wall and bridging across a blocked cavity, or it's water getting pushed/sucked up from the ground in masonry which is porous (and some Victorian "colliery brick" I've come across is like a sponge) in a house which lacks a DPC. So first off you need to find out if your wall is cavity wall or solid - and if it is cavity you do need to find out if the cavity is blocked, but please don't be so dismissive of injection DPCs, they do work for a lot of people in stone terraced houses.

 

[opps]

Regarding the condensate pipe and bucket. Would a week have been long enough for the damp to dry out?

Any soakaway should be filled with lime chippings because of the corrosive nature of the condensate. I have seen dripping condensate pipes eat their way through concrete.

 

[JohnD]

looks like a water leak to me, and there is a lot of water.

is it all round the house? higher in certain areas? or just in particular places? please stand back and take some wider pics, inside and out, and especially of the "highest point" of the damp, if there is one.

As you are in a terrace, I presume all the other houses were built with the same materials and techniques, at the same time. Are they all damp? Do they have damp patches, and do those patches coincide with, say, a kitchen, bathroom or downpipe?

does rainwater lie on the paving, or run towards the house wall?

please sketch the position of drains, gutter downpipes, gullies and manhole covers

and water pipes, sinks and taps, and especially the incoming supply pipe. Does it run under the hall floor? is the floor solid or wood with a ventilated void beneath? Is the floor wet?

have you got a water meter?

do you know where the outside and the inside stopcocks are?

do you have access to sharp young ears?

p.s.
why doesn't the condensate run into a drain?

 

[George_engineer]

Agree a leak and exacerbated by condensation is most likely.

Caveat with I don't think this is the primary cause - but I would remove of some of the cement strap pointing and investigate the condition of the original lime mortar behind. Potentially water is getting trapped by the cement not allowing the wall to dry, thus making condensation more likely.

 

[Deleted member 174758]

and water pipes, sinks and taps, and especially the incoming supply pipe. Does it run under the hall floor? is the floor solid or wood with a ventilated void beneath? Is the floor wet?

Drawing shows a cellar. Typically there will be a keeping (coal) cellar at the bottom of the steps which is the most common point of entry for incomers, although not always. Pre-1900 a lot of stone built terraces had stone flag floors, at least above the cellar. I have to admit that before posting I assumed thay the OP would have thoroughly investigated potential waste and water pipe leaks, including the condensate pipe, and stuff like downpipes, troughing, etc

p.s.
why doesn't the condensate run into a drain?

 

[Deleted member 174758]

Potentially water is getting trapped by the cement not allowing the wall to dry, thus making condensation more likely.

But condensation is most often associated with black/grey mould in areas of low airflow (e.g. backs of wardrobes) and near the tops of walls where moisture laden air is more likely to cool. The OPs photograph clearly shows damp at the bottom of the wall above the skirting, which I'd associate more with leaks, mortar-filled cavities, etc

 

[JohnD]

I wonder if it really does have a cavity? I'd have thought too old, but am not familiar with this type of build.

it's possible for water to get into a cavity, and then soak into the builder's waste invariably found in it. it's a hard but rewarding job to clean out a cavity.

 

[Deleted member 174758]

@JohnD - ours is 1881 and cavity. The first house on this street was 1875 and was cavity, too. Cavity walls started to come in a lot earlier than many people think in the Pennines, at least. Probably down to the availability of cheap "colliery brick" to form the inner skin.

"Colliery brick" was often made by coliery companies, or firms adjacent to pit heads, using clay extracted from pit workings, combined with coal "pickings" (small, otherwise unsaleable coal, sometimes almost dust). These bricks were used to line pit shafts and shore-up underground roadways and were made in vast quantities very cheaply, far cheaper than dressed stone, but they were often mis-shapen, could be porous, and weren't really of the quality you could use on the outside of a building - but on the inside, where they would be plastered over, who would ever see them? Commonly used in colliery districts from the early part of the 19th century (and a lot of Lancashire and West/South Yorkshire was colliery country - the Pennines were also stone country)

Incidentally, the cavities in this type of wall are so narrow that cleaning them out can often require chopping back the plasterwork, knocking out individual bricks, clearing out, and rebricking, before moving further down the wall and repeating the exercise (over and over). I've done this and it makes injection DPCs seem a lot more attractive as an option, especially if you go belt and braces and render to waist height afterwards

 

[RandomGrinch]

ours is 1881 and cavity. The first house on this street was 1875 and was cavity, too. Cavity walls started to come in a lot earlier than many people think in the Pennines, at least. Probably down to the availability of cheap "colliery brick" to form the inner skin.

If it's a terraced house it's unlikely to be rubble infill - by 1875 that was normally only used on bigger buildings like banks with a wall thickness of 1m or more

I'm afraid I would have to disagree
Stone inner and outer, and most definitely rubble infill on our 1890's South Wales stone terrace

 

[Deleted member 174758]

I'm afraid I would have to disagree
Stone inner and outer, and most definitely rubble infill on our 1890's South Wales stone terrace

That's South Wales. Different geology, different stone, different building vernacular. I live on the Lancs/Yorks border area, in the Pennines, and I have worked in Lancashire and Yorkshire stone districts for long enough to know that rubble infill disappeared as a construction methodin a lot of houses in this area well before 1900. Many of the residential buildings which had rubble infill in this part of the world were condemned as uninhabitable (because of damp) in the 1960s under the slum clearance program of the day, compulsorily purchased and demolished. There are exceptions, though (e.g. the many under dwellings in Hebden Bridge) which is why I stated that the OP needs to ascertain the method of wall construction. BTW, how deep are your window boards and how thick are your walls?

 

[RandomGrinch]

BTW, how deep are your window boards and how thick are your walls?

Thanks, your insights are always valued
Walls are 16" and window boards are around 9-10".

 

[migmags]

looks like a water leak to me, and there is a lot of water.

is it all round the house? higher in certain areas? or just in particular places? please stand back and take some wider pics, inside and out, and especially of the "highest point" of the damp, if there is one.

As you are in a terrace, I presume all the other houses were built with the same materials and techniques, at the same time. Are they all damp? Do they have damp patches, and do those patches coincide with, say, a kitchen, bathroom or downpipe?

does rainwater lie on the paving, or run towards the house wall?

please sketch the position of drains, gutter downpipes, gullies and manhole covers

and water pipes, sinks and taps, and especially the incoming supply pipe. Does it run under the hall floor? is the floor solid or wood with a ventilated void beneath? Is the floor wet?

have you got a water meter?

do you know where the outside and the inside stopcocks are?

do you have access to sharp young ears?

p.s.
why doesn't the condensate run into a drain?

As you are in a terrace, I presume all the other houses were built with the same materials and techniques, at the same time. Are they all damp? Do they have damp patches, and do those patches coincide with, say, a kitchen, bathroom or downpipe?

no damp anywhere else in the house
please sketch the position of drains, gutter downpipes, gullies and manhole covers

There are non on the front elevation
do you know where the outside and the inside stopcocks are?

Yes - not the issue.

why doesn't the condensate run into a drain?
I assume a soakaway beneath the the front patio - there's no way of knowing without digging.