Help needed regarding blocked drains please!

New Build Inspections

bindu4076

New Member
On 17th December, we noticed that the water was flushing right up to the rim and draining very slowly.

The customer care department said "since we had lived in the property for the last 18 months, then the problem could not be with the drains but most likely due to things that shouldn't be flushed down the drains". I was also advised to get a drain blockage company to take care of the problem.

I called in a CCTV drain survey company. Two inspection chambers were completely blocked. After hosing with garden hose, they found a contractor's measuring tape in one inspection chamber which was creating a blockage in that particular IC. I did not see any reason why the other inspection chamber was also blocked but had my suspicions.

The survey report raised more questions than it answered as I do not know the implications of some of the findings.

After jetting, most of the drains had 5% residual water on 100m pipes. Is this normal?

Drainage flowing downstream to next door neighbouring property No.11 in diagram below has residual water of 40% of water height on a 100mm pipe. Is this what is called a backfall that is preventing the flow from our property to next door.

Attached is a copy of the survey. I think the gradients between IC1, IC2 and IC3 may also be wrong!!

DSC00028.jpg


Any guidance would be much appreciated!!
 
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NewHomeExpert

Well-Known Member
First of all, it is totally ridiculous to suggest that after a certain time, any issues with new home drainage is because the owners are the cause of the blocked the drains. Any problems could be due to subsidence, cracked pipes, collapsed pipework.
It is even more stupid to suggest this for your blocked STORM drain! (SW)
It really does show how little BELLWAY HOMES and most other major house builders care about their own customers and helping to put things right, even within the two year warranty period. It is easier to fob you off than to help!

For a start, the gradient or fall between SW IC1 and SW IC2 is just 40mm in 12.6metres.
It should be at least 1:100 meaning a fall of 126mm. As it is, it is virtually level.
This means that any deviation or variation in the pipework between the two manholes will cause water to be left behind in the pipe - residual water.

As you have now found the CAUSE was due to Bellway's contractor, Bellway Homes are liable for the cost to clear the blockage, the cost of the CCTV survey and a reasonable amount for yourself for your time spent managing the rectification of Bellway's defect on Bellway's behalf as Bellway had suggested!

You should now write a formal letter to Ted Ayers CEO of Bellway:
Bellway Homes Plc, Seaton Burn House. Dudley Lane, Seaton Burn, Newcastle upon Tyne, Tyne & Wear. NE13 6BE
enclosing a copy of the CCTV survey and invoices, photographs etc demanding that you be reinbursed and that Bellway return to your property and ensure your drainage complies with NHBC standards. Please also send a copy of the letter to the NHBC. Drainage is covered for the full ten years, so they will be interested in learning of this.

From what you have said, your neighbour has a bigger issue with half the pipe not draining away. With such shallow falls, I suspect that this pipe is indeed backfalling, due possibly to settlement.

The gradients to FW IC3 - FW IC2 is 440mm in 1400mm is OK.
The fall between FW IC1 - FW IC2 is 440mm in 4300mm around 1:100, so this should be fine too. Not sure the bend in the pipe is very good though, perhaps it is schematic!
 
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bindu4076

New Member
NHE

Thank you for the advice. I am in the process of contacting NHBC about the drains as well. I just need to clarify some more points.


FW = Fowl Water Drains – Run in back garden from our property No.13 to No.11 (left on the schematic diagram)

FW IC1 - (small bin IC)….was blocked…the contractor’s measuring tape was found in this.
FW IC2 - (large IC)…………not blocked but had a little residual water
FW IC3 - (small bin IC)….was blocked
FW IC4 - Is in the back garden of property No.11.

I am still not sure about the fall/gradient on the FW system.

I may be wrong but my calculations for a fall of 1 : 100 are as follows:-

FW IC3 – FW IC2 ….should this not be 12mm in 1200mm (440mm in 1200mm is too steep)
FW IC1 – FW IC2 ….should this not be 43mm in 4300mm (440mm in 4300mm is too steep)
FW IC2 – FW IC4 …..residual water of between 10% - 40% after jetting which indicates a backfall.

If the falls/gradients are too steep, then the water would clear a lot faster than the sludge leaving the sludge behind. This would explain why IC1 and IC3 were both blocked at the same time.

SW = Surface Water Drains – Run in the front from our property No.13 to No.15 (right on the schematic diagram)

SW IC1 – SW IC2 ….not blocked….not yet! I hadn’t even noticed the lack of fall until you pointed it out in your post below!

SW IC1 to an "unknown" inspection chamber in the left side alley…..is "blocked". This IC looks like it in the next door property. I do not know if "blocked" means it is a buried IC or it is inaccessible because it is over the fence in neighbouring property or if this IC is actually really blocked with leaves etc from the surface water. I have asked the drain survey company for more clarification.
 
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NewHomeExpert

Well-Known Member
Blocked means a blocked drain.
There should be no residual water in Foul drainage (FW)
Minimum FW falls should be 1:100 too.
You cannot really have too steep, although sometimes a back drop is used to save on excavation but not required in this case.
You are right that water could clear quicker than "solids" but they would get cleared anyway with this fall.
 

Rochdalian

New Member
If a drain is too steep then solids can get left behind as the water flows away - I wouldn't recommend any steeper than 1:40 maximum or flatter than 1:80 minimum for foul. The surface water drain is kind of OK-ish provided the gullies are maintained properly, though as it appears to be a shared line you're at the mercy of other users.

The levels on the plan puzzled me for a second - I'm used to invert levels being AOD where the number decreases as the drain falls. To my eyes, the drains running uphill!:rolleyes:

I work on wastewater networks for my sins. :eek:
 

bindu4076

New Member
Just an update on our drains problem!

After confronting Bellway with a copy of dvd survey that I commissioned on my property, the entire foul water drain system on my property as well as certain drains on my neighbour's property has to be replaced. In fact, my neighbour had two buried inspection chambers which were inaccessible and eventually had to be dug up and replaced and situated so that they are easily accessible. One surface water drain in my neighbour's property was not connected to a mains drain and the surface water was being discharged into soil close to the their foundation (about 2 feet from their front kitchen wall). The soil is solid compacted clay and when it rain,s this area remained soggy for days afterwards. This has now been remedied and connected to the main drain which was just one foot away!!

A number of other homeowners also were complaining about smells inside their properties from the foul water drains. I advised them all to get their own camera drain surveys done. When the builder realized that I had been talking to the other homeowners and had bought the drains problem to the attention of the NHBC, Bellway decided to commission their own surveys using the same company that I had privately engaged for my property as they were "so impressed with their service." I think this is just a euphuism for "well we can't say that there is nothing wrong with the drains now...and since NHBC are now aware of the problem...we might as well do the other properties as well." The end shot is that about 10 other properties had their foul water drains remedied!! Now that the other homeowners in the development know that there is a problem with the drains, Bellway has started getting calls from other homeowners who think they may also have a problem with their drains. They are currently carrying out remedial work to the drains on the property of my neighbour on the other side...18 months after they bought and moved into the property!

Our property is on a slight slope downwards and the builder has decided that the surface water drains do not need replacing even though they are not laid at the minimum requirements for surface water drains as they said that "these drains will only be discharging water which will eventually flow away naturally anyway"!!!. I had a suspicion that a surface water drain between my property and my neighbour's property was not connected properly. Bellway said they had reviewed the dvd survey tapes and they did not see anything wrong with drain. However, I asked for copy of the dvd survey and found that this particular surface water drain connecting into an inspection chamber had disconnected and was discharging water into the soil between the two properties. This was eventually dug up and reconnected to the inspection chamber.


All in all...a right **** up job all round. It seems that a number of surface water drains have been left to drain into the soil around the homes. The garden spaces are not big enough to take the amount of surface water from the rainfall that we have our area. No soakways have been built to take the extra water. So...a large number of gardens get soggy and do not drain away quickly. The soil is solid clay and therefore there is constant swelling and contraction of the soil around the foundations of the properties. I just hope the foundations have been built correctly to take this into account!!!

Watch this space!
 

NewHomeExpert

Well-Known Member
It just demonstrates why house builders would be better:
1) Properly supervising the works in the first place.
2) Not using sub contractors who employ idiots to do the work.
3) Not to try and make the problem go away with excuses and incorrect resposnes that everything is alright without proper checking as soon as thier customers make a complaint.

I for one really hope this ends up costing BELLWAY HOMES an absolute fortune, but somehow I suspect the sub contractor will be forced to pick up the bill.
I also hope that others will read the posts on this forum and others and NOT BUY A NEW HOME from Bellway or any other house builder for that matter!

As for your foundations, they should have been designed and constructed (excavated deep enough) so that the ground bearing strata would not move.
In addition the NHBC should have inspected the foundations before the concrete was poured.
Then again, he should have inspected the drainage before it was covered up too!
 

tiffanywelch

New Member
On 17th December, we noticed that the water was flushing right up to the rim and draining very slowly.

The customer care department said "since we had lived in the property for the last 18 months, then the problem could not be with the drains but most likely due to things that shouldn't be flushed down the drains". I was also advised to get a drain blockage company to take care of the problem.

I called in a CCTV drain survey company. Two inspection chambers were completely blocked. After hosing with garden hose, they found a contractor's measuring tape in one inspection chamber which was creating a blockage in that particular IC. I did not see any reason why the other inspection chamber was also blocked but had my suspicions.

The survey report raised more questions than it answered as I do not know the implications of some of the findings.

After jetting, most of the drains had 5% residual water on 100m pipes. Is this normal?

Drainage flowing downstream to next door neighbouring property No.11 in diagram below has residual water of 40% of water height on a 100mm pipe. Is this what is called a Blocked drains bromley backfall that is preventing the flow from our property to next door.

Attached is a copy of the survey. I think the gradients between IC1, IC2 and IC3 may also be wrong!!

View attachment 105


Any guidance would be much appreciated!!
Hi every time I use sink in bathroom it makes the shower fill up with horrible waste and when I use shower it fill up quick and I havevto switch it off to letvit go down before during it on again also checked all the pipes white ones under Dink nothing stick in them and at bottom of shower there is mess and my shower is in separate room it's square tray can you help tried five mi Ute drain unlocker bleach boiling water and steamer thanks steph
 
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sounds like you got a blockage somewhere ....i had a client last week and the sink was blocked ....it turned out the plumber or some one had sabotaged it and put foam filler in pipe
 
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