Victorian house - damp kitchen wall

[Fuzzer]

Hello everyone,

We just bought with my partner a house a few months ago that we knew had some damp issue.
The patio on the back of the house was laid too high and on top of the dpc. As well, the stones were just sitting next to the wall without any gravel channel or anything.
So you can imagine that during the years, a lot of water was pushed into the bricks. On top of that, there is a concrete render covering all the back of the house, stopping maybe 2 bricks higher than the dpc.

The damp issue that we had is now mostly fixed. We had a damp wall in the dining room, but after the plaster was removed and let to dry we haven't see any issue come back. Same with the kitchen that is sharing part of the same wall with the dining room.

The only issue that is not resolved is the small retaining wall between the outside door of the kitchen and the window.
I removed the plaster and render in September, and left it to dry since then. We have the dehumidifier running every night and installed an extraction fan for cooking just after we moved in.
Yet the bottom of the wall is still damp, up to about a meter.

I started to dig outside to check if the dpc was damaged, or if we any in that part of the house. It seems like a bituminous layer was added as a dpc at the bottom of the wall, I could sort of smell it when I was cleaning the wall.
You can also see that on the phots, there is some gaps at the bottom of the wall, some missing bricks.
Inside the kitchen, you can see that the bottom of the wall is damp, there is even soil or gravel directly in contact of the wall.

I don't know if the damp problem is just that the wall is saturated with humidity after years of neglect. Or if we have more of an issue with humidity coming from the ground into the wall that is directly in contact.
We are just a bit lost as of now, so if you have any suggestion that will be greatly appreciated.

Thanks!

 

[Cubist]

Hello Fuzzer and Welcome,

I notice the kitchen sink and washing machine are sited immediately beside the problem area. Is there any evidence of current or old leaks from these? Does the washer include a tumble dryer and where is that vented to?

 

[Fuzzer]

Hi Cubist,

Thank you for the reply.
We noticed that we we moved in, the condensation under the kitchen sink was really bad. The humidity level in the house was really high mostly due to the bad ventilation and high ground level.

We didn't noticed any leak from the sink or the washing machine. The drain from the sink is going straight into the ground, the waste pipe was open in the kitchen and is going outside of the house.
I don't know if the leak could be coming from the waste pipe and sipping into the wall?

I have attached some more photos after cleaning up a bit the bottom of the wall.

 

[Cubist]

I think the prime suspect has to be the cavity(ies?) you've unearthed outside the rear door and these need to be dealt with sooner rather than later. Is there any evidence that a waste pipe was carried through one of these at some time in the past?

Nevertheless, clean them out as best you can and fill them all with a mortar mix pushed firmly into the holes and repair any failed pointing in the immediate area. Let this dry out and monitor the internal damp to see if any improvement after heavy rain of if tested with a hose pipe (not a pressure washer in this case). May also be worthwhile checking whether the DPC has been bridged by the newish mortar pointing that can be seen in the pics.

Would also be worthwhile keeping an eye on the water feeds and waste exits (including steam vented from tumble dryer) as it goes through a cycle. I'm not sure if you meant that a flexible hose from the washer is simply inserted into a upvc waste pipe behind the cabinet - it's a common approach. That UPVC pipe may have a blockage (kids socks, forgotten tissues, all sorts of rubbish) and/or pump pressure on the drain cycle may be sufficient for the drain to overflow indoors. there is also a possibility any joints in the waste pipe have failed and water is escaping inside the wall. Another thought is that steam venting from a tumble dryer could be condensing in cold air immediately behind the cabinet and the wall and that too could be the cause of excessive damp.

 

[MatthewC]

You say

The patio on the back of the house was laid too high and on top of the dpc. As well, the stones were just sitting next to the wall without any gravel channel or anything.
So you can imagine that during the years, a lot of water was pushed into the bricks. On top of that, there is a concrete render covering all the back of the house, stopping maybe 2 bricks higher than the dpc.
The damp issue that we had is now mostly fixed.

but it's not clear to me if you have one anything about the lack of a gravel channel (or better, a French drain) outside? Also, have you checked the cement render? If water gets behind it then it can't get out, and it looks as though your bricks really are damp which must be coming from somewhere, even quite high up. From one of the photos the wall opposite the door (presumably your neighbour) has cracks and things, and if your wall is worse then I'd be looking at that. You also need to check all the rainwater goods.

 

[Fuzzer]

Thanks for the answers.
We removed all the stones and will be installing some French drain all around the back of the house.
There was damp on the other back walls but after removing the render inside and digging the ground outside fixed the issue, the bricks are now completely dry.

The only damp present is that small wall in-between the kitchen door and the window. You can see the damp is rising up to 1 meter or slightly more. After cleaning you can even see that the bricks under the floor are also.

We don't have a dryer, it is just the washing machine next to that wall. But I haven't seen any leak coming from it. I really looks like the damp is coming from the foundation and traveling up the wall.
I will explore that issue with the cavities, we might have some water traveling under the wall are rising inside the kitchen wall.

The back of the house was rendered a few years ago before we bought it, haven't seen any crack yet. Just don't know how bad it was before that and how much water got inside the wall before it got fixed.

 

[Fuzzer]

Hi again,

So a bit of an update for today.

I did dig a bit more to have a look at the cavities around the door like suggested.
It seems that when the kitchen door was modified, some bricks were removed and not replaced. The ground in the gap was just directly in contact with the bricks, you can see that the dpc is also missing.

There is a gap as well in the foundation underneath the door. I don't know exactly why but you can see a layer of brick, clay, then another layer of brick and the dpc on top.

The cavity on the right looks like the gas main, if anyone can confirm? I think that one is alright, just going under the dpc and is enclosed in mortar at the back.

 

[Cubist]

I think you've found the source of your problem. Ground water will have been getting into the wall through those cavities and perhaps over a very long time. They all need to be closed and the DPC repaired as far as possible. The lead pipe is almost certainly gas but you can easily verify that by checking where it exits behind the cabinets.

 

[Fuzzer]

Hi Cubist,

Yes it really looks like the root of the problem. Time to find a good stonemason to have that sorted, and leave the wall dry inside again for a few months I guess.
Thanks again for the advice, I'll try to update the post when I have that sorted.

PS: Bonus pic of some old pottery found at the bottom of the foundation

 

[Cubist]

Hi Fuzzer,
This old place has been occupied for approx 500 years. Hate to think how much pottery, glass and metals I've dug up but the most interesting finds, beyond a few medicine and alcohol bottles was a tin of old buttons. Sadly, no real treasure but one lives in hope of a trove. Ho hum.