rising damp, penetrating damp, percolating damp, who else wants to get creative?

[TofuSpaceship]

As you can see from this first picture, we are having a massive infiltration problem around the chimney breast.

To give some general information, we are at the ground floor of a two storey Victorian house. To the right of the picture there is the external wall. We have been living in the property for 2.5 years and the problem has surely worsened.
To be precise, the damp/humidity problem affects the chimney breast and adjoining wall on the right side, as it can be seen from pictures below. Plus there is some mould-like patch on the following wall, which is external. When ripping up the floor in this area, a forest-musty smell came up. There is a bay window in this external wall, it has a couple of air bricks at the bottom which are free on the outside, haven't checked yet the situation on the inside.

This picture is the external wall, in the alcove. It looks more mould than anything else

This picture is the alcove on the opposite side, as you can see this side is perfect.

Now we are having a look under the floor level, where the biggest infiltration problem is. As you can see in the picture, on the right I see a DPC, I don't see any DPC continuing towards the front of the chimney breast. Evidently that joist is quite damp.

A view under that very same joist

Here is a view of that very same joist on the left and the DPC on the adjoining wall.

These two pictures are taken in the corner of the external wall, where there is that mouldy patch at mid-height. As you can see the chipboard that sits directly under the wall has turned into a friable sponge. It is dry to the touch, but it also hasn't rained heavily for quite some time.

This is a view of the sub-floor area under the front of the chimney breast, funnily enough it looks in pretty good conditions!

A couple of (potential cowboys) dampmen have been around. I am not really amused with their quick and dirty "rising damp" explanations.

To be remarked also, last year on that external wall we had the fascia/soffit and guttering re-done, as some rainwater was coming down the fascia onto the wall. So maybe that could have been the cause of the mouldy patch, but I am again dubious as it is just a patch mid-height on a wall on the ground floor, the rest of the house in that area looks fine (we do have wallpaper upstairs though).

I personally fear there is actually a couple of problems going on: the plaster in the chimney breast is bubbly, meanwhile the external wall is more mould-like, surely that has to do with two different causes? Also, chimney breast no DPC, maybe that is really rising damp, but the other walls have DPC, so probably it shouldn't be rising damp?
Anyway, I really am not sure how to fix this problem and who to turn for advice, hence I hope some of you guys can point me in the right direction or has maybe a tip on how to find a good damp specialist!

thanks

 

[bobasd]

There's no easy way to repair what you've revealed - if you as a DIY'er do the work then it's simple to do but will take time.

Why not stand back, and Post pics of the whole room for context,
and pics of the internal and external sides of the room's RH outside wall - the bay area?

In pic one remove all the skirting along that back wall and chimney breast. Is the back wall a party wall or an outside wall?
Hack off plaster to a height of 1m. all along above where the skirting was.
Mini hack saw off the external angle beads at 1m - use plastic angle beads when making good.
Remove proud nails from joists and lift the carpet gripper strips.
Remove all debris to outside the house.

You will have to cut out some of the joisting and do further works but for now, do the above and when its done pic it and come back here.
Is the chipboard going under a partition?

Previous attempts at repairs have been unsuccessfully attempted.

Does the CO alarm work.
While doing this work you could wire in DSS outlets in both recess alcoves - at 18" high on the back wall.

 

[JohnD]

what is on the other side of the walls in that corner where all the water is? Is there, for example, a room that contains water pipes?

Have you got a water meter?

 

[TofuSpaceship]

bobasd, we can do the repair work ourselves and will do.
However, my main source of concern is understanding where all this damp/wetness is coming from. I don't want to make everything nice, and then find myself a square one in 10 years because we haven't tackled the root cause.
Alarm CO works, thanks for the concern!
I will take some more pictures once the rolled carpet is out of the way and I removed the skirtings, maybe I will draw a diagram too.
You are saying previous attempts of repairs have been unsuccessful; you should see the whole floor and how it is supported, it is out of this world. 4 by 2 used as joists, propped up by a mix of either other 4 by 2 stuck into the ground (and rotting at the bottom) or some breeze block pillars!

JohnD, on the other side of the wall there is the neighbour, she should not have anything water-y in that area, I will definitely knock at hers and have another look.

 

[H2Gizmo]

Well... It depends... New dpc. For sure as for below the doc . There is a school of thought that with old places you should open it all up, let the air flow around. Air brick.. Lower the ground on the level on the outside.. Or cut back vegetable.. Let it all breath. Or you can go down the tank it method. Doc and tank the inside of the brick wall the re plaster over the top... Rising damp for sure.

 

[JohnD]

Rising damp for sure.

Or a leak.

For sure.

 

[TofuSpaceship]

Here is the long awaited diagram.

Also here is a view of the outside, with 2 of the 3 airbricks and the gutter in the corner.

JohnD a leak has not been ruled out, still need to go round the neighbour's house to check what's happening at her end, but she is not home

H2Gizmo I am starting to think it is more penetrating damp than rising damp. We have these three air bricks outside, retrofitted. They are quite in line with the floor level inside , rather then being below. It doesn't feel like air is free to circulate.
Further, the gutter at the corner looks like it is a bit undone on the elbow, so it could be that it leaks slightly when it rains, making the whole front garden damper than it should.
Finally, upon ripping up of the whole floor, the situation all along the external perimeter is not great and the soil is damper than you would think.

Our next steps are therefore knocking at the neighbours to inspect for leaks at her end, making sure the gutter elbow is not leaking and building a french drain all along the external wall.

 

[bobasd]

thanks for the new info.
still waiting for the other pics mentioned above and could you post pics showing the front elevation?

1. air bricks above the floor line are useless. sub-area through ventilation from front to the rear of the property is necessary. best practice has air bricks set between the joist tails bays and at min of 150mm above ground level. the 150mm is not always possible.
2. your external render should not be in ground contact, esp as you might have solid walls.
3. the garden wall butting up to the house could be causing penetrating damp in that area.
4. your new pic shows a down pipe and a drainage piece presumably taking rainwater to either a sump or simply spreading it in the garden.
5. all RWP connections must be firmly fixed and leak proof.
6. your neighbour will have a mirror image chimney breast to yours, and possibly similar damp issues as well.
7. hold off on digging a French drain.


8. pic one shows what looks like a 15mm cu pipe on the left of the c/breast - is that a redundant gas pipe?
9. do any of your neighbour's have a gulley at their front elevations?

 

[JohnD]

The rank undergrowth shows the ground in that corner to be very wet. Stand back please and show us a wider view of the walls, gutter, roof, and especially of the gulley (or pond) that the downpipes gushes into.

No doubt the gulley will be cracked, leaking or blocked.

The downpipe may be as well, since the damp is quite high.

 

[TofuSpaceship]

1. Will keep that in mind. Is it a silly idea to remove soil from the front garden so that it is then much lower than the airbricks as required - but it would also be below sidewalk level
2. Copy that, see above
3. You mean the garden party wall between ourselves and neighbours I believe? Why would they be? Surely when that wall gets wet, it'll dry out naturally not being rendered, rather than transferring damp to the house?
4. It's actually taking rainwater onto the sidewalk and then he water runoff onto the street, pretty common setup on the whole street for every house
5. We believed that the bottom bend was perhaps leaking but it looks to be sealed
6. Neighbours don't have chimney breast, they have their chimney breast adjoining the next neighbour, if that makes sense
7. Ok, reason being? Not being arrogant (I hope I don't pass as such) , I'm really eager to understand it all
8. Redundant
9. Some neighbours that we know of have a French drainage. Or you mean a bottle gullet thing ? Then the answer is no, every house on the street discharges rainwater onto the street ( see point 4)
Thanks again for your help on this.

I've attached more pictures, in order:
A. Showing the opposite corner of the external wall, not as bad as the corner in object, but it's quite damp here too
B. Overview
C. View of down pipe
D. View of the airbrick / garden from the other angle (just outside picture A.)
E. Picture from above of the party wall with e neighbour ( point 3 above), it is actually detached from the building
F. Another view of the damp corner in object

 

[TofuSpaceship]

The rank undergrowth shows the ground in that corner to be very wet. Stand back please and show us a wider view of the walls, gutter, roof, and especially of the gulley (or pond) that the downpipes gushes into.

No doubt the gulley will be cracked, leaking or blocked.

The downpipe may be as well, since the damp is quite high.

Hi JohnD, as mentioned the downpipe is offloading onto pavement / street.
The gutter / down pipe has been replaced last year, damp was already present before that and damp is still there, so probably it is not gutter / downpipe related.

 

[bobasd]

why not pic the internal side of the bay showing the underfloor area?
have you discovered a DPC in any material?
the garden level looks pretty low compared with the front threshold.
the gap at the end of the garden wall needs cleaning out.
the render could be allowing moisture to penetrate the front elevation? you will have to remove he plaster high up inside where theres damp smudges.
do you have access to under the hallway floor?
do you know if it has adequate ventilation?
if the down pipe and "gutter" were replaced, why two different materials round and square?

 

[JohnD]

I wonder why the garden and the wall are so wet next to the downpipe.

Coincidence?

 

[TofuSpaceship]

I wonder why the garden and the wall are so wet next to the downpipe.

Coincidence?

Hi JohnD, most likely not a coincidence, however the whole external wall of the living room is damp, albeit it is showing different level of dampness.
Hence, the downpipe could be a cause of dampness (and will make sure to verify in the next few days that it is absolutely sealed), however that doesn't explain why on the opposite corner of the living room there's damp I am afraid!

 

[TofuSpaceship]

why not pic the internal side of the bay showing the underfloor area?
have you discovered a DPC in any material?
the garden level looks pretty low compared with the front threshold.
the gap at the end of the garden wall needs cleaning out.
the render could be allowing moisture to penetrate the front elevation? you will have to remove he plaster high up inside where theres damp smudges.
do you have access to under the hallway floor?
do you know if it has adequate ventilation?
if the down pipe and "gutter" were replaced, why two different materials round and square?

There's DPC made of slate in the external skin of the wall, I can picture tomorrow in the sunlight
If you are referring to the actual door threshold, that is misleading as the uPVS frame is quite thick and it is not flush neither to the outside tile nor to the inside floor. Tomorrow I can measure accurately garden level vs internal floor level in the living room
I will try to clear out the gap with a spade
Are you suggesting that it could be a good idea to remove a strip of render, say where the air bricks are?
I did access the hallway floor last year, are you interested in anything specifically? I hadn't witnessed any damp down there, but to be fair I only lifted a floorboard and inspected with a torchlight.
If you are asking about ventilation under the hallway, I don't think it has any.
Well, that is a very good question! The black round gutter is the new one, builder wanted to complete the job but we told him not to, as it was in our plans to re-do the front garden at some point and we were potentially going to do a little trench to accommodate the final bit of the guttering. We haven't come round to do that.

May I ask why you were suggesting me to hold off with a french drain? In the meantime, I am quite tempted tomorrow to excavate some soil at the feet of the front elevation, say a foot or so, with the hope that the house could start breathing better + removing all the rubble and a bit of soil along the inside perimeter.