cracked sewer pipe - home made video and pics taken

[bloxy123]

Hi there,

I was hoping to get some advice on my DIY drain surveillance after suspecting our sewer pipe is the cause of some damp issues we're having (damp wall adjacent to downpipe).

I bought a cheap inspection camera so excuse the bad camera angles but think I caught the problem? - the video/images are of where the downpipe meets the sewer pipe and what looks like a plant root with tissue on it? or could it just be the joint for the 90 degree bend and some tissues stuck? the gap looks a bit big for the joint though..

Video:

Images:

https://*********/9qUDhGO

https://*********/9WgzjWD

https://*********/fQAQWYk

https://*********/kehsalQ

https://*********/avnqswc

https://*********/fmSfQvd

https://*********/VZuJ1x0

Any advice most appreciated.

Thank you,
Stuart

 

[Timmy D]

Very hard to see, ideally you want to get all the tissue off. Put a hose pipe up there?

Saying that, something doesn’t look right.

 

[bloxy123]

Very hard to see, ideally you want to get all the tissue off. Put a hose pipe up there?

Saying that, something doesn’t look right.

Good shout.. I’ll give it a go after work tomorrow and report back with another video.
Thanks

 

[Chuck]

the video/images are of where the downpipe meets the sewer pipe and what looks like a plant root with tissue on it? or could it just be the joint for the 90 degree bend and some tissues stuck? the gap looks a bit big for the joint though..

IME, leaks due to movement are common at the foot of a downpipe. Once there's a small crack, roots will find there way in and start causing blockages by trapping paper and 'stuff'.

It's possible that what you've found is the cause of your 'damp wall' issues but it could be unrelated. Have you checked the gutter above the area for leaks? Are there any overflow or pressure relief outlets in the vicinity?

 

[bloxy123]

IME, leaks due to movement are common at the foot of a downpipe. Once there's a small crack, roots will find there way in and start causing blockages by trapping paper and 'stuff'.

It's possible that what you've found is the cause of your 'damp wall' issues but it could be unrelated. Have you checked the gutter above the area for leaks? Are there any overflow or pressure relief outlets in the vicinity?

Ok thanks.. so I cleared the drain with a hose I have found a small crack, but no root (pipe is is under concrete slabs and a concrete base (perhaps the cause of the crack?)

I checked the gutter this evening and all seems fine - I will need to get up some ladders to make sure over the weekend. And we have a soil vent pipe but it hasn't got a cap on top so will need to check it's not blocked as our toilet does gurgle when it's flushed - could this have caused the crack?

I've attached an image of the crack.. do you think it is large enough to cause damp issues in the house though? The walls are pretty damp..
maybe I need to get a drain survey to detect any bigger issues I haven't found.


thanks again!

 

[ShaunCorbs]

That drains dropped / moved as there’s a lip which is causing a slightly blockage needs digging up and mending

 

[bloxy123]

That drains dropped / moved as there’s a lip which is causing a slightly blockage needs digging up and mending

Ok thanks. We’re not having any blockages but assume this is a cause for the damp/leakage? No waste smells coming from the ground / walls though - just the usual damp smell.

I’ll get the Hilti dusted off

 

[Chuck]

I checked the gutter this evening and all seems fine - I will need to get up some ladders to make sure over the weekend.

Don't risk falling off a ladder. I'd wait until it's raining and have a look with some binoculars.

And we have a soil vent pipe but it hasn't got a cap on top so will need to check it's not blocked as our toilet does gurgle when it's flushed - could this have caused the crack?

Gurgling may be blocked vent, e.g. by a birds nest. Won't have caused the crack you've found. That's be due to some sort of movement in ground, e.g. settlement or shrinkage (if it's a clay soil).

I suppose that if the down pipe is blocked and can fill with water, when this happens a leaky joint could spray water onto the wall. This is a bit of a stretch, however.

The walls are pretty damp. maybe I need to get a drain survey to detect any bigger issues I haven't found.

Can you provide a picture of the damp wall? IME, the source of the damp is not likely to be higher than about half way up the damp patch. Although 'rising damp' gets a lot of publicity, it's actually very rare; I don't think I've ever come across a real example.

 

[bloxy123]

Don't risk falling off a ladder. I'd wait until it's raining and have a look with some binoculars.


Gurgling may be blocked vent, e.g. by a birds nest. Won't have caused the crack you've found. That's be due to some sort of movement in ground, e.g. settlement or shrinkage (if it's a clay soil).

I suppose that if the down pipe is blocked and can fill with water, when this happens a leaky joint could spray water onto the wall. This is a bit of a stretch, however.


Can you provide a picture of the damp wall? IME, the source of the damp is not likely to be higher than about half way up the damp patch. Although 'rising damp' gets a lot of publicity, it's actually very rare; I don't think I've ever come across a real example.

OK thanks.. I'll wait for the rain.

So I've attached some images of the wall and have added one image with some arrows where the damp is running - It rises about 1m and is dampest on that wall (damp meter reading hitting near the maximum) so assuming this is the source.

The wall on the left is our neighbour's (semi detached victorian)

Excuse the mess - we dug up the old floor for obvious reasons.. hence why I'm trying to find the damp cause before laying the new flooring!

 

[Chuck]

I assume that your 'damp meter' is a 'surface resistance' meter, with a couple of metal probes and and a meter that essential measures the electrical resistance between them. If so, this is a terrible way to investigate the moisture content of masonry / plaster walls. (In my opinion, this method is only useful as a rough method for checking the moisture levels in samples of timber.)

(FYI, the correct method is to drill a small core, crush then weigh it accurately, bake in a low temperature oven and measure the weight loss.)

From the information given, I'd say that the most likely cause of the damp surface, which is all you've detected, in the green highlight is going to be condensation. There appears to be a kitchen/utility area in the room next to the damp wall, which someone has removed the door from. Water vapour from the kitchen/utility will move into the 'office' and condense on the first cold surface, i.e. the section of external wall circled in green.

That said, the outside shots do seem to have a lot of moss, e.g. around the gulley that serves the kitchen and the waste pipes don't look correctly positioned to me. They need to discharged into the drain not spray water around the edges because this will, obviously, soak into the ground and eventually saturate it.

You can see that the waste pipes exit the wall with several cm of stand-off but someone has clipped them tight against the wall at the discharge end so a significant fraction of the discharged water is probably soaking into the ground. Another possibility is that the gulley is blocked and overflows when used.

 

[bloxy123]

I assume that your 'damp meter' is a 'surface resistance' meter, with a couple of metal probes and and a meter that essential measures the electrical resistance between them. If so, this is a terrible way to investigate the moisture content of masonry / plaster walls. (In my opinion, this method is only useful as a rough method for checking the moisture levels in samples of timber.)

(FYI, the correct method is to drill a small core, crush then weigh it accurately, bake in a low temperature oven and measure the weight loss.)

From the information given, I'd say that the most likely cause of the damp surface, which is all you've detected, in the green highlight is going to be condensation. There appears to be a kitchen/utility area in the room next to the damp wall, which someone has removed the door from. Water vapour from the kitchen/utility will move into the 'office' and condense on the first cold surface, i.e. the section of external wall circled in green.

That said, the outside shots do seem to have a lot of moss, e.g. around the gulley that serves the kitchen and the waste pipes don't look correctly positioned to me. They need to discharged into the drain not spray water around the edges because this will, obviously, soak into the ground and eventually saturate it.

You can see that the waste pipes exit the wall with several cm of stand-off but someone has clipped them tight against the wall at the discharge end so a significant fraction of the discharged water is probably soaking into the ground. Another possibility is that the gulley is blocked and overflows when used.

Thank you so much - all your advice is greatly appreciated. You are correct - I am using a meter reader with 2 metal probes, however, the wall is actually wet to the touch and the masonry below the plaster is very wet too. Obviously, the DPC isn't doing its job so will sort this once I've found the cause.

You're also right on the drain - I've just taken a photo of the drain with the tap running and the water doesn't go directly into the gulley. You can see concrete surrounding the drain is broken so the water must be seeping through at a fair volume right?.. think we might have found the cause? don't worry I won't hold my breath!

The mains water doesn't come in close vicinity to this area (comes through the other side of the house and up to the second floor where it returns back down to our kitchen). I have followed the water pipes through the house.

We have only just bought the property so the damp problems have all been a great surprise. Any advice to anyone reading this is to get a full building survey.. We've learned the hard way with all the asbestos we are also having to remove.

 

[Chuck]

however, the wall is actually wet to the touch and the masonry below the plaster is very wet too. Obviously, the DPC isn't doing its job so will sort this once I've found the cause.

A couple of comments:

Firstly, don't jump to conclusions, it is never 'obvious' whether an in situ DPC is working or not. Secondly, condensation will make the wall feel 'wet to the touch'.

If, for example, the previous occupant was in the habit of drying washing inside the house and did so over a period of months or years the walls and plaster could have absorbed a lot of water that could will a lot of time, warmth and ventillation to fix. A dehumifier can work wonders in such cases.

Another thing I'd check is the 10cm channel topped with stones along the foot of the exterior walls. The key point is it's there for a reason and you need to figure out what that reason is. It may be a gutter filled with shingle or a French drain that ends up in a soakaway. If it's become blocked and not stopped working that may be a factor.

Be careful about employing a 'damp proofing' company out of the phone book. There is a lot of snake oil on the market and a lot of cowboys selling it. You can spot the con artists because when they do their 'survey' they use a meter like yours to prove you need them to install a new DPC. Then, when the problem doesn't go away, and you want your money back they start drilling core samples and baking them to prove the masonry isn't wet.

I think you should consider employing a chartered surveyor with an interest in 'damp problems' to help you to diagnose and sort out this problem. Not to put too fine a point on it, you're missing basic things and are going to end up wasting a lot of time and money unless you get help (or do a lot of self-study).

 

[bloxy123]

A couple of comments:

Firstly, don't jump to conclusions, it is never 'obvious' whether an in situ DPC is working or not. Secondly, condensation will make the wall feel 'wet to the touch'.

If, for example, the previous occupant was in the habit of drying washing inside the house and did so over a period of months or years the walls and plaster could have absorbed a lot of water that could will a lot of time, warmth and ventillation to fix. A dehumifier can work wonders in such cases.

Another thing I'd check is the 10cm channel topped with stones along the foot of the exterior walls. The key point is it's there for a reason and you need to figure out what that reason is. It may be a gutter filled with shingle or a French drain that ends up in a soakaway. If it's become blocked and not stopped working that may be a factor.

Be careful about employing a 'damp proofing' company out of the phone book. There is a lot of snake oil on the market and a lot of cowboys selling it. You can spot the con artists because when they do their 'survey' they use a meter like yours to prove you need them to install a new DPC. Then, when the problem doesn't go away, and you want your money back they start drilling core samples and baking them to prove the masonry isn't wet.

I think you should consider employing a chartered surveyor with an interest in 'damp problems' to help you to diagnose and sort out this problem. Not to put too fine a point on it, you're missing basic things and are going to end up wasting a lot of time and money unless you get help (or do a lot of self-study).

Thanks Chuck,

All great advice. I've created a make-shift fix to the drain using a rubble bag and I fortunately have a dehumidifier which I'll leave on for a week+.

I added the stones myself for the french drain - previously it was filled with mud and 10mm shingle so I cleared it 30cm deep and added 20mm shingle with a non-woven geotextile at the bottom. so it's a soakaway currently.

Once I get more time I'll find a more permanent solution and if all is still failing I'll get a drain survey done and look into getting a surveyor round. I'll report back with any news.

 

[Ayamk1]

Thanks nice idea share sewer pipe line. I'm doing Sewer repair in Burnaby