Tracing a suspect pipe path and finding a leak

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Doggit

If the house was built in the 30's then I don't think there's an issue with the foundations, and most of london is built on clay, and it expands when wet, and shrinks back when dry. That's the reason that most houses built on clay, have a raft design for the foundations. If there is no evidence of any cracks in the walls, then everything is fine. The DPC will be about 6" to a foot above the ground level, and can be seen by a blackish line, or a thicker mortar bed. This stops timber etc getting wet, and keeps the house dry.

But in you case, if I remember the start of this thread, you've got issues with damp under the floorboards, so some concrete with a waterproofer added and poured under the floorboards to provide a seal, might work best; it wouldn't stick to the clay, but set above it, and keep the water out.
 
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Thanks John and Doggit.

I totally agree with you both. So for safety my aim now should be to quickly close up the Trench. But I would be grateful if you could tell me before I close it up, what do I do on the outside? Do I concrete the foundations or something else or do I leave them as is and simply put the clay back?

Also what about the water in the Trench? Do I leave that and just fill it back up with soil?

I think you're getting mixed up with floorboards because that in a room upstairs. Down in the basement it's just a concrete floor.

Also there is zero dpc.

What waterproofer shall I use?
 
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if you prefer not to put the soil back, don't use anything like strong concrete as it might stop the footings moving in time with the rest of the house. I'd be happy enough with a good hardcore mix including dust compacted down, but you'd be better waiting for some of the more experienced members to advise.

If you really want a definitive answer/peace of mind then pay an SE for advice.
 
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To be honest, since you've told me there is a risk of movement of foundation stones due to no support from surrounding soil, I want to now close it off ASAP.

Does this mean I shouldn't concrete the foundation stones at all? If not, how else can I protect them?

I am eager to get this done within the next few days, so any advice to protect the outside foundations in any way would be greatly appreciated.
 
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John, sorry I forgot to ask, whom are you referring to as "more experienced members" ???

Also I thought I'd update you a little. I spoke to the tech guys at http://www.kabuildingproducts.co.uk/

These guys are extremely helpful. The person has had a look at the photos of the cellar and the water problems and has advised that I plug any large holes on the outside wall with WATER STOP/HYDRAULIC CEMENT and then paint the KA Tanking Slurry on all the wall, including the foundation stone. He then said that I put a 4-5inches of concrete down next to the foundation stone. The concrete must be mixed with a waterproofing additive such as the KA SBR Bond. He said that these are not the only products on the market and I was free to purchase similar ones elsewhere, but he was just giving them as examples.

What do you think? Would this work?
 
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John, sorry I forgot to ask, whom are you referring to as "more experienced members" ???
No one particular, but I've had a few incidents with know it alls on the plumbing forum getting abusive when I've tried to help people, so when I'm not 100% I tend to leave that in as a disclaimer.
 
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What do you think? Would this work?
I don't know, it all sounds implausible to me, but houses are more resilient than you think.
Old houses are generally in some kind of balance, so whatever you change will affect that.
Even if dumping a load of concrete in would somehow block the water, it would build up outside and put pressure on the wall until it found another way though. If you put a continuous DPM around your house the clay might dry out so you can't win that way!
If you can drain the water away on the outside that would be good, but good luck whatever you do.
 
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Doggit

Okay, without reading through everything again, what are we trying to achieve here. You've got water coming down the hill, and the concrete in the basement is wet, so you need to plug the holes up that you've dug out, and putting an additive in the concrete wouldn't hurt, but the water will still come though the other sections, so yes, use the tanking slurry in the basement, and as they've suggested, you'll need to then screed the floor etc after it's tanked.
 
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John - I agree, water will always be there, that's why since I can't drain it away, at least I can try to reduce the amount coming through.

Doggit - Thanks. My goal is to seal the house as best as I can to reduce or stop the amount coming through. You've recommended the slurry and concrete on the inside of the basement, but what about the outside? Is concreting on outside foundations not worth it?
 
D

Doggit

Think about it Ripper. A, it's been there for 80 years and is fine, and B, you could dig down all around the house and tank it, but you can't get underneath it, so it'd still be getting wet from the bottom upwards.
 
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The problem is doggit that I don't really know how long this issue has been on-going. It could have been only a few years or longer. What I do know is that water standing against clay which is supporting the foundation can't be good for the property....especially if the clay has gone so soft that you can poke your fingers under the foundation stones....surely that can't be right, can it???

Have a look at this concreting idea mate and give me your honest opinion of what you think:

View media item 100656
 
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I think you should search out a decent structural engineer and/or groundworker to get a proper diagnosis of this issue... it’s not really a Plumbing and Heating issue. Where are you located again?
 
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I did get a ground worker and they said there's most likely a hole/gap somewhere along the footing stones that's letting the water in and all I need to do is what's been said before - concrete and seal with some form of damp-proof membrane.
 
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D

Doggit

Dilalio has a good point, because we're not on site, and they may spot something pertinent, but what I will say, is that if you decide to go for the tanking slurry route, then there's no point in doing the cement as well, and there's no point whatsoever in doing the clay, as the water will be seeping down under the cement, and back up again.
 
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Doggit, you're right in saying that water may still be able to bypass the concrete getting under it, then behind and above it, but surely by having concrete I am protecting the clay from getting washed away from fast water coming down the hill?

I'm also thinking what John said earlier that without the support of the surrounding soil the footing stone can move, so won't the concrete be extra support for it?

Lastly you said that I should concrete internally, but if you're saying water can get past concrete, then how would this help?

Sorry for so many questions. It's just that I'm trying to understand what you're trying to say.
 
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