Extending drain by less than 45 degrees

[OldKettle]

Hi,
I am currently in the process of buying a property which has an inspection chamber within a "porch" area which connects the house to an outbuilding. The outbuilding has double brick walls, and I wish to fully connect it to the house (losing the porch in the process).

There is a flat roof running the whole length of the outbuilding, plus the porch and the right hand side of the porch (as viewed in the attached image) is a brick wall, with the right side being a double glazed door.

I am awaiting a full inspection of the drainage, but it seems that a drain must run under the garage to the IC, with the WC and shower connecting to it (there is also a bathroom on the upper floor, approximately above the WC on the ground floor).

I am not clear whether the kitchen and downpipes connect to another drain, or whether they connect to the IC directly (there is no other IC or rodding point in the garden to permit rodding to a further drain, and the owner believes that the drains only serve that house).

I am very keen to either remove the inspection chamber, or build over it in situ and provide rodding access outside the buildings.

To do this, the drain would obviously need to be extended to the new IC/rodding point. If the angle of the new drain was less than 45 degress, could this been done while leaving the existing IC in place? With that configuration, could I permanently build over the original IC in the knowledge that it would never need to be accessed again?

Things become more complicated if there is a drain along the back of the house (rather than just direct connections at the IC). In that case:

If that drain only carries water from the gutters and, possibly the kitchen, does it need rodding access at the original IC location? Could rodding access be added at an external point on that drain?

I've attached a couple of drawings (sorry about the rough quality) to hopefully illustrate the situation.

Any thoughts would be much appreciated as I would really like to avoid keeping the IC within the building (even with the double seal cover).

EDIT: I should mention that the house was built in the mid 50s and I understand that the drains are still the original construction.

 

[Hugh Jaleak]

Need a better idea of where the drains run before advising further. Building regs state all drain runs must be accessible for rodding if required, depending on what is currently accessed from that chamber, will determine what you can do with it.

If its a shared drain, then its the Water Company's asset, so you'll need their permission to do anything to it.

 

[OldKettle]

The survey has not given a very detailed picture of the drains (it was only a homebuyers report, so I didn't expect too much information).

As expected there is a drain down under the garage and out along the driveway.

There is also a drain coming from along the rear of the property, and also "quite a large pipe" (according to the surveyor) coming in from the outbuilding. However, there is no IC or rodding point to allow rodding of the outbuilding pipe to the IC, and also no obvious IC/RP to rod the pipe coming from the back of the building (either on the property or the neighbour's property).

Clearly this will need further investigation, and I'd appreciate any thoughts on how to proceed.

I have looked into CCTV drain surveys, to comply with Severn Trent requirements, which is the relevant water company (WRC standards and block plan with direct line tracing).

I'm I likely to need a different companies to do the survey and the actual moving (if possible) - or should I try to find a company that can do both?

Any thoughts would be much appreciated.

 

[Ian H]

You should get a company to do both, what quotes have you had for the CCTV so far?

A company to definitely avoid would be Building Happy Homes.

 

[OldKettle]

The only quote I have had so far is £250 plus VAT for a CCTV survey (need to check if that would be to Severn Trent standards).

I'm trying to arrange for a couple of drainage companies to have a look.

The first one said that they would definitely need a CCTV survey to tell what work would be required. The second said that they may be able to get a good enough idea without CCTV.

 

[Ian H]

I would try these for a quote:

http://www.ansaltd.com/

I think their CCTV surveys are about £140+VAT and that will include jetting if needed and a full written report with site plan and still photos.

Just think though, whoever you choose to do it will only be able to CCTV drain runs with access such as a rodding eye or man hole.

 

[OldKettle]

Thanks, I will get in touch with them.

Just think though, whoever you choose to do it will only be able to CCTV drain runs with access such as a rodding eye or man hole.

I think I only need them to survey the drains that run from the IC. I'm assuming that, if there is a lateral drain along the back of the property and if it is shared with adjoining properties, then access from the known IC should be sufficient to map it.

However, your comment makes me think I am probably missing something.

 

[OldKettle]

I'm going to have a couple of contractors have a look at it tomorrow. I asked about the CCTV survey, and to satisfy Severn Trent standards it would be £420 + VAT for before and after surveys.

I spoke with the company Ian suggested this morning and was promised a call back today, but nothing so far.

 

[OldKettle]

I've had a couple of contractors have a look now, and this is what I was told:

1st contractor

• It could definitely be moved outside at an angle of less than 45 degrees
• When I asked about rodding access he said "we wouldn't rod it, we can just power wash it"
• That there is one pipe running a short distance in from the outbuilding and one that runs a short distance along the back of the house, picking up the drainpipes and pipes from the kitchen, that pipe bends 90 degrees at the IC and then under the garage and out to the street
  
• Would cost about £2,500 + VAT
• No mention of needing a CCTV survey
• No mention of building regs

2nd Contractor

• It could definitely be moved outside at an angle of about 30 degrees, if the run along the back of the house is not shared with neighbours
  
• The building regs guy he works with would pass it, but the council building regs guy might not
• It is unlikely that the drain run is shared, but would need a CCTV to confirm (£180 + VAT)
• If the drain is shared it is still doable, but would cost much more to move all the required drains
• Would cost £2,500 to £3,500 + VAT if drain is not shared

Any thoughts on the above would be much appreciated.