Why is this wall damp?

[GeX]

House was built around 1900.
This wall is the gable end of the house.
Floor is timber, suspended.
DPC is around 6 years old.
It is a cavity wall.
No cavity insulation.
Has cavity ties.
House was repointed approx 9 months ago.
Sofits and fascias were replaced around the same time.

House was damp when we bought it, and it had a lot of the ground floor knocked back to brick around 1m up and then replastered in lime plaster. This wall was not done.

The damp spots on these walls predates any recent work that was done on the house. I wanted the pointing done before reviewing them as there's little point re-plastering if there's water getting in through the exterior bricks.

Can see in the hallway there is a large patch that spams from the window. A second, smaller patch futher down, and theres another near the front door.
In the foreground - you can see there's a damp patch in the corner of the dining room. This one is most visible when the weather is humid. I had some people look at this a couple of years ago, and they couldn't see any reasson for it. Suspected it might be a cold spot caused by cavity wall ties.

In the corner, the wall gets damp. There are water marks on the wall further up and near the radiator.

Exterior, looking towards the back of the house.

and then looking at the edge of the window, where the big damp area is in the hallway

Chatting with the guys who did the pointing, they couldn't see any issues where previously letting water in.

I realise I'm going to have to get people in to look at this, and likely replaster the entire wall as once it's wet.. it's wet - but just wondering if there's anything glaring going on that I've missed.

 

[dlockers]

House looks way newer than 1900, it looks like you have a cavity wall (vents + brick layout). Have you checked gutters/roof?

 

[Glanza]

Have you checked if it's still sealed above the window? on your pictures looks like there is a gap.

 

[GeX]

House looks way newer than 1900, it looks like you have a cavity wall (vents + brick layout). Have you checked gutters/roof?

It isn't, there's a date plate on the house and I have a copy of the original deed.

Yep, there's a cavity as I said - there are no gutters on the gable end but the front and rear are all new when the roof work was done.

 

[GeX]

Have you checked if it's still sealed above the window? on your pictures looks like there is a gap.

Yep, it's sealed. I checked when the scaffolding was up for the pointing and it was sealed up. It wouldn't explain the other damage tho even if it was leaking there.

 

[-Ad-]

Strange as a 1900 house will be solid wall, but you clearly have a cavity outer wall there looking at the bricks.

My worry is it's a solid internal wall with an extra wall put up on the outside. Is there any DPC on the older internal wall, or just on the outside one?

I'd still be checking around that window as there's clearly something to have caused the damp patch there.

The patch around the bottom of the radiator is low and looks to be where the outside downpipe or Openreach box is on the outside. Have you checked around those for any penetrations or mortar that's a possible ingress point? Or is that a different room further along?

 

[GeX]

Strange as a 1900 house will be solid wall, but you clearly have a cavity outer wall there looking at the bricks.

The patch around the bottom of the radiator is low and looks to be where the outside downpipe or Openreach box is on the outside. Have you checked around those for any penetrations or mortar that's a possible ingress point? Or is that a different room further along?

Yep, it is odd that it has a cavity wall - it's why I mentioned it. There is def a cavity there, I ran the cables through for the fibre and they go into the cavity and then out under the floor.

There is no DPC I'm aware of on the internal wall. It was not part of the works done when we bought the house. Other internal walls were treated but this one was deemed to not need it at the time.

The downpipe isn't near enough to the radiator, the Open Reach box was fitted after the damp was already present. The main damp bit in the corner of the dining room is the other end of the room - the where the side gate is.

 

[dlockers]

What heating system is it? F&E tank in the attic maybe leaking through cavity?

 

[GeX]

It’s combi, so no tanks. The boiler is on that wall but up in the loft, it was moved and replaced about 5 years ago too.

The bathroom is above that part of the hall but I can’t see anything under the bath leaking, it doesn’t align with where any pipes run.

Whilst the hall looks the worst, I’m more concerned about the patch in corner of the dining room. The hall looks bad because the paint has a sheen that’s missing at that angle / lighting

 

[GeX]

Wonder if the cavity is just full of 100 years of debris

 

[b0rn2sk8]

You said it was repointed 9 months ago, was that with lime or cement?

 

[GeX]

Lime, I’m not an idiot

 

[koolpc]

Looks like the window is the culprit to me. Just look how the damp has spread out from it...

 

[GeX]

Counterpoint, it’s cold near the window so condensation forms there. The window is in the outer course of bricks, the damp on the inner.

There’s more damp than the window, that’s just the most noticeable.

 

[dlockers]

I had a wooden door with a similar arch above it and it was sodden. Cavity being full of junk seems likely. The fact there is a cavity and no dpc is super odd imho.

 

[gingergundog]

Rotten/missing cavity tray above the window? Might need a new cavity tray and some weep vents.

If getting any low down damp, it maybe needs some dryrods fitted internally. You make a good point about debris, had the same problem.

 

[Mason-]

There is no DPC I'm aware of on the internal wall. It was not part of the works done when we bought the house. Other internal walls were treated but this one was deemed to not need it at the time.

Do you know for sure there isn’t one on the internal wall, because if there isn’t that could likely be (one of) the issue(s).

As there is a cavity it’s unlikely to be damp driving in from the external wall, unless like you say there is some debris acting as a bridge in the cavity.

 

[GeX]

When I say there is no DPC, I mean there is nothing I have done or seen - therefore I don't know if it exists. I'd assume it was built with one of some sort.

Other internal walls were treated with

DPC Injection Cream – 1 Litre – PAM Ties Limited | Basement Waterproofing And Damp Proofing

pamties.co.uk

Looking back at photos when this was done tho.. that corner looks watermarked

I missed that at the time, and that wall wasn't treated.

How does one clear out the cavity, remove some bricks and make a mess?

 

[JRJ]

Not to insult your intelligence @GeX but are your sure there's a vertical cavity in the wall? The external vents look more like suspended floor vents, would be interesting to know your internal floor level compared to the external wall, I can see where your fibre cable enters through the vent? and would come out under the floor as described.

Negating that option if there is a cavity, as has already been mentioned by @gingergundog I'd be looking at the window and the cavity tray, I had issues in an older house with no cavity trays whereby the window fitter went crazy with expanding foam and bridged the cavities the wrong way leading to similar damp issue which manifested around the window and diagonally out from the window about 12feet into another room.

 

[GeX]

I'm not at that house at the moment, so can't grab any photos - but I distinctly remember reaching up from under the floor in to the cavity to to grab the pull wires for the fibre. You can see the thickness of the wall by looking at the window in the hall, and there are also cavity wall ties installed by previous owners - and all the surveys came back saying it had cavity walls.

Can I easily tell if there's a cavity tray, or a faulty one above that window - or does it mean making holes through the plaster above it?