Broken and cracked sewerage pipe in the garden - options?

[cammy0102]

Hi ladies/gents, I'm new to the forum. I'm after a bit of advice regarding my situation. I'm trying to pick the best option for repairing a damaged sewage pipe.


I have a ground floor garden flat in West London (period conversion) which I have been living for about year now. There 2 man holes in my garden - main one in the side return and the other manhole/interceptor at the back of the garden. These have been blocked a few times this year (tenant in the upstairs flat said they've been blocked multiple times in the last few years and that there's a structural problem) so I got a CCTV drain survey done using Dyno Rod. This highlighted a number of issues in the sewage pipe between the 2 manholes - couple of broken joints, root intrusion and crack in one place. According to the survey, the damage was most likely caused by ground movement and recommend silica lining to create a new path inside the pipe (pretty expensive quote provided).


We made a claim against our joint building insurance and this has been approved. The Insurance Loss Adjuster wanted a 2nd quote so I arranged arranged a company called Diamond Drains (also in West London) to inspect the drain problem and give me another quote, which came in a bit cheaper. He gave me 2 options - One to reline the pipe like with Dyno Rod quote and the other to replace the defective section (about 8m) of the pipe. I believe the replacement pipe material is plastic and this work will carry a one year guarantee whereas the reline option would come with a 10 year guarantee. Relining option is slightly more expensive but it's not a problem as the Loss adjuster reckons it's up to me who I choose for the repairs and how I get it done (obviously within the allowed limit plus I have to show invoice). I am new to all this stuff but to me, a replacement plastic pipe sounds like the better long term option.


I should mention that part of the pipe (about 5m) between the 2 manholes is under a newly laid patio and this section according to the drain survey is fine. The problems start about 7m from the main manhole. So if I go for the replacement option, part of the clay pipe between the 2 manholes will stay (the 5m section) and this will be connected to a plastic pipe that runs toward the interceptor manhole.


Since there is nothing in the garden at the moment (my Landscape gardner cleared it and prepared for the new lawn) digging is not an issue.


Here's an image of the layout to make more sense of what I'm talking about.


What option would you go for if you were in my situation?


PS: apparently I also have a problem with the interceptor manhole. The reason this one keeps getting blocked is due to the old design (U bend), I've been told. To rectify it, I'll have get it redesigned to have a straight pipe which will cost about 1300. I don't have the money at the moment but what are your thoughts on this? When I get the above work done, I'm going to ask the guys to pressure jet it and also have a look in the interceptor to see if there's anything in there that might be blocking it.


Thanks in advance for any input.

 

[cammy0102]

Well it wouldn't let me post the link to the image.

Basically there's an extension at the back and patio around it. Main manhole under this patio in the side return. The interceptor manhole about 13m away from it in the garden (back of it).

 

[joni os]

Biggest problem with interceptor is bung in rodding eye goes missing and then syphon fails to self clean. With syphon flushed clean and new bung to seal rodding eye manhole should perform as intended, without additional works.
Depth of manholes is not given but for depth not exceeding 1.5 metres my personal choice would be excavate and replace. Provided plastic pipe has 6" pea shingle surround laid in accordance with Building Regs. There is no reason not to expect 50 yrs plus of service life.
Other services, gas, water, BT etc. need locating prior to any machine excavation. Back in the late 60s, a couple of men from Cricklewood would have hand dug in a day, thinking £6 a shift was good money.

 

[Best]

Plastic sewer is best if done right and inexpensive, even allowing for new manholes.
Replace all clay sewer pipes you can, particularily any that could be later below concrete, etc areas.

 

[cammy0102]

Plastic sewer is best if done right and inexpensive, even allowing for new manholes.
Replace all clay sewer pipes you can, particularily any that could be later below concrete, etc areas.

I really don't want to break the new patio so I'm going to have to leave that bit of clay pipe intact and only replace the damaged section with plastic pipe.

Have you guys had any experience with relined sewage pipes? Do they last long?

Will having multiple joints in the new pipe (if I go for replacement) cause problems - there will be joints between clay-plastic, plastic-plastic, etc.

 

[cammy0102]

Biggest problem with interceptor is bung in rodding eye goes missing and then syphon fails to self clean. With syphon flushed clean and new bung to seal rodding eye manhole should perform as intended, without additional works.
Depth of manholes is not given but for depth not exceeding 1.5 metres my personal choice would be excavate and replace. Provided plastic pipe has 6" pea shingle surround laid in accordance with Building Regs. There is no reason not to expect 50 yrs plus of service life.
Other services, gas, water, BT etc. need locating prior to any machine excavation. Back in the late 60s, a couple of men from Cricklewood would have hand dug in a day, thinking £6 a shift was good money.

I think the depth is less than 1m.

I am not sure about the gravel around the plastic pipe (this wasn't specified) but I could ask the guy.

So everyone recommending replacement of the damaged section with a plastic pipe instead of relining option?

 

[joni os]

Relining for street works or deep pipelines, but for pipes in back yard, not exceeding 1 metre depth, excavate and relay is cheapest and best option.
Shingle surround necessary for proper support of plastic pipe. If your builder is unaware, use another builder/groundworker.
Special collars, Clay to plastic pipe, easily available.
This work should be notified to building control and inspected by them. This will involve a fee which should be recovered from insurance.

 

[snowhead]

Don't go the relining route.
I've seen about half a dozen done on commercial properties and I can't remember 1 that hasn't failed.

As above if it's accessible replace the pipe.

 

[Radioman]

Replacement every time if possible, joints are not an issue if done to building control spec. As said above, works are notifiable to building control who will inspect before the trench is backfilled. If your chosen contractor is unaware or reluctant get another contractor as BC cert will be needed if you sell the property or experience further issues. Also get hard copy of Public Liability insurance and phone insurers to make sure it is current just like the old bill do with car insurance. Also FYI contractor is liable for claims against his work for 6 years not 12 months. You might want to check https://www.businesscompanion.info/en/quick-guides/consumer-contracts/mixed-contracts

 

[oz-plumber]

Find out if the re-lining company is going to do the entire drain or just the damages sections.
Seen a few misconceptions about this over the years.

As for replacing the drain and leaving an old section under the patio, that would be asking for trouble in the future.
If the existing pipe has cracks and tree roots, then over time the section of pipe under the patio will have as well.

 

[gmartine]

Although painful to rip up a newish patio should also come up easily enabling the paviers to be relaid at significantly less than the original cost of installation, replace as much pipe as possible.

 

[cammy0102]

Thanks a lot for your replies guys.
You've convinced me to go for the replacement option.


As I said before, I'm reulctant to break about 5m of newly laid sandstone patio. When the drain survey done last week, they said this section of the pipe was fine.
So we are going to keep this section and join it up a new plastic pipe which will run to the Inerceptor manhole.
Anyway the contractor said he'll stick the camera down to see if it's fine before carrying on with the work.


I've already emailed him and asked about building regs and pea shingles to support plastic pipe. I've also asked for the material of the pipe.


thanks.

 

[cammy0102]

I just spoke to the contractor. He said as this is not a new drain (only a replacement pipe for a damaged section), I don't need a building control certificate. But he said he didn't have any problems me arranging it and he'll be doing the work according to building regulations and yes he will have pea shingles to support the pipe. I am not going to bother as this is going to delay things and it's going to cost a couple of hundred pounds.

 

[Best]

I just spoke to the contractor. He said as this is not a new drain (only a replacement pipe for a damaged section), I don't need a building control certificate. But he said he didn't have any problems me arranging it and he'll be doing the work according to building regulations and yes he will have pea shingles to support the pipe. I am not going to bother as this is going to delay things and it's going to cost a couple of hundred pounds.

I could believe if you were just replacing a straight length of sewer, that no need to notify building control, but you said there are bends to be done entirely different and other things. So I would say building control would need to inspect it all. Remember you need it to new regs where possible - rodding points for every run and bend, junction.
Simple way to find out for free, - just ring your local building control and ask to speak to building inspectors. I doubt if it would cost £100s for an inspection.

 

[cammy0102]

It's just a straight pipe between the 2 manholes and no bends.

There is a separate issue with the interceptor manhole but I'm not getting that replaced or anything. Contractor going to pressure hose it and said he'll stick his down there to see if he can find any rocks or any other hard stuff. and go from there.

 

[joni os]

If building control are involved cost paid by insurance company. Check with Loss Adjuster.
Building notice submitted online, Inspector on site within 48 Hours, minimal delay.
This is a very straight forward job, although being London, parking, access and disposal will probably double the cost.

 

[Radioman]

Don't be scared of Building Control, they will be on your side and prevent shoddy or incorrect workmanship and materials also,as said cost will be recovered from insurance. A quick call will establish the need or not. Average charge is £150 for 2 inspections and all the application is done on line, site attended within 48 hours, however advice over the phone or face to face is free. Ultimately the decision is yours, £150 versus £5000 fine and a big mess to clear up if it all goes wrong.

 

[cammy0102]

I rang Hounslow council earlier and told them about the repairs to drains. He said it was a grey area and it was up to me whether to apply or not. He said I could apply for a building control notice and then start the work tomorrow then tell them couple of days before they are about to backfill so they can come and inspect.

I was going to apply for the building control notice and I emailed the contractor. He told me he's had lots of delays with building control people in the past and that he'd have to charge a penalty fee if the building control guy doesn't turn up or is delayed.
I can understand that he doesn't want his work being held up.

I am now not sure whether to apply for this or not especially considering it's not really required by law.
If they charge me extra than what's quoted, Insurance might not pay the extra.

What do you guys think?

 

[joni os]

If you haven't already awarded the contract, engage another contractor. Jetting the interceptor is also suspect. Bung in rodding eye, water in manhole, plunge syphon, should leave clear, confirmed with flexible drain rod.(resembles spring). Normal soil water detritus can, if necessary, be removed from syphon, but broken pipe and arising's from intended works could block it solid. Ensure syphon is clear before and after works. I've had my fallout with building inspectors, but this job is so simple there is only one way to do it right. Reluctance for work to be inspected and one year warranty does not encourage confidence.

 

[cammy0102]

If you haven't already awarded the contract, engage another contractor. Jetting the interceptor is also suspect. Bung in rodding eye, water in manhole, plunge syphon, should leave clear, confirmed with flexible drain rod.(resembles spring). Normal soil water detritus can, if necessary, be removed from syphon, but broken pipe and arising's from intended works could block it solid. Ensure syphon is clear before and after works. I've had my fallout with building inspectors, but this job is so simple there is only one way to do it right. Reluctance for work to be inspected and one year warranty does not encourage confidence.

They are starting the work tomorrow so bit late to change now. The chap seemed good when he came around and they have really good reviews on checkatrade. As for the interceptor manhole, he didn't say he was gong to pressure hose it. He said he'd stick his hand in their and see what's in there while they are doing the other work.

 

[cammy0102]

I had a good chat with the guy over the phone before. He said he doesn't have a problem with me applying for building control and he doesn't want the work held up if building control person doesn't turn up as he'll have to pay the 2 guys. He confirmed in an email that he'll be reasonable and only charge extra if their work is delayed by a day.

 

[Radioman]

What if the building control officer turned up and condemned the work as not correct, listed instructions on the rectification meaning that your contractors work was not up to current code? Would your contractor still have your confidence? Have you physically checked his public liability is in order and that his labourers are also covered, bet they are not on PAYE, FYI checkatrade references have proved worthless. Why ask for advice from the guys on here and then not accept it? Building control certificates are a legal requirement not a matter of choice. Sewerage disposal is a serious issue.

 

[cammy0102]

What if the building control officer turned up and condemned the work as not correct, listed instructions on the rectification meaning that your contractors work was not up to current code? Would your contractor still have your confidence? Have you physically checked his public liability is in order and that his labourers are also covered, bet they are not on PAYE, FYI checkatrade references have proved worthless. Why ask for advice from the guys on here and then not accept it? Building control certificates are a legal requirement not a matter of choice. Sewerage disposal is a serious issue.

Of course I take your advice on board. That's why I'm going for the replacement option, rang building control and had a chat with the contractor.

So far what I"ve found is if you repair a drain pipe, you don't need building control certificate but I've applied for it as you guys have recommended it.

If the work is not up to standard, then I can ask him to fix that but if his guys can't carry on with the work if the building control guy doesn't turn up,it's hardly fair that he has to foot the bill.

I am just being pragmatic but I'll have building control certificate.

 

[Radioman]

Of course I take your advice on board. That's why I'm going for the replacement option, rang building control and had a chat with the contractor.

So far what I"ve found is if you repair a drain pipe, you don't need building control certificate but I've applied for it as you guys have recommended it.

If the work is not up to standard, then I can ask him to fix that but if his guys can't carry on with the work if the building control guy doesn't turn up,it's hardly fair that he has to foot the bill.

I am just being pragmatic but I'll have building control certificate.

Your not repairing you are replacing, but thanks for taking our advice.

Don't forget to check PLI. Make this a habit whatever contractor you employ. My PLI was around £400 pa and I really enjoyed giving a copy to any customer who asked for proof. Last year the next door property to us was having major works which involved scaffolding on my land. The owner just assumed I would give permission for the scaffold, I asked for the contractors PLI and scaffolding licence. Guess what, he had neither. So permission was refused. It then transpired that none of the subbies had it either.

 

[oz-plumber]

I, for the life of me, cannot understand why you would not get the whole drain replaced, if the insurance company are offering to pay for it?

You will find it very hard to claim on it again in the future.
I think you are extremely lucky to have the insurance company offer to pay for repairs on the current drain you have.