Building Over a Shared Sewage Pipe

Gangu

There is a manhole giving access to a shared sewage pipe at the back of a house we've gone sale agreed on. It's at the back of the house, in a kind of lean to conservatory that was added on. We're hoping to extend, demolishing the lean to. Does this mean we can't build over this manhole? As we'll need to be able to access pipes if they get blocked? Is there a workaround? We're starting to look for an architect for the extension, but it would be helpful to know.

jArgHA

Hello, i just received advice today on very similar issue. Speak to building control section in your local county/city council to discuss building regulations.

regards

K.Flyer

For various reasons you should NOT build over a manhole be it sewerage or otherwise.
If you intend to build on an area where a manhole is located you must move the manhole to a different location. This will involve extending / re-routing all the individual lines that ran into the original manhole to the new location so that access can be gained for cleaning as was posssible from the original manhole point.
Another good reason is to prevent odours and sewer gases from escaping into your building and also if there was to be a blockage do you really want sewerage creeping up under your new floor.

BryanF

jArgHA wrote: »

Hello, i just received advice today on very similar issue. Speak to building control section in your local county/city council to discuss building regulations.

regards

why not tell us what advice you got from building control ?

martinn123

In certain situations, you can use a sealed manhole cover.
It's airtight so you get no gas leaking into Conservatory.
Fitted correctly it will be safe, however if there is a blockage in the pipe, it's access for rods
Take advice before proceeding.

K.Flyer

martinn123 wrote: »

In certain situations, you can use a sealed manhole cover.
It's airtight so you get no gas leaking into Conservatory.
Fitted correctly it will be safe, however if there is a blockage in the pipe, it's access for rods
Take advice before proceeding.

Unless you have witnessed first hand the horror of one of those type of manhole covers being opened to access a blockage within the confines of a house and raw sewage suddenly overflowing from the manhole and the smell and clean up operation involved you would never have any sort of a manhole under any house extension floor.
Believe me its not a good idea.

martinn123

K.Flyer wrote: »

Unless you have witnessed first hand the horror of one of those type of manhole covers being opened to access a blockage within the confines of a house and raw sewage suddenly overflowing from the manhole and the smell and clean up operation involved you would never have any sort of a manhole under any house extension floor.
Believe me its not a good idea.

I agree completely, but in some situations, it's the only solution, other than not building the extension.

K.Flyer

martinn123 wrote: »

I agree completely, but in some situations, it's the only solution, other than not building the extension.

Agreed, and I know that some may never give trouble, unfortunately I have seen a few disasters that would cause me to advise against it being indoors. If I was building the extension I would prefer to divert all the pipework and move the manhole to a point outside of the extension. However, thats easy enough if the depth is a metre or so, if it was any deeper, cascade type or has an interceptor then you could be stuck with it.
If it had to stay in situ, I would be having it cctv checked first for signs of potential ongoing problems.

sillysocks

Bringing up an old thread here but it's a kind of related question.

Has anyone ever encountered pipes like these being a problem where they run under where the new extension would be built? Hoping to build an extension onto our house and while the manhole cover itself would still be in the garden and not part of the new extension the building itself would go over where the pipes currently run. When we open the manhole cover the pipes are about 6 feet deep in the ground, and look like they are quite wide.

4Sticks

There are engineering solutions to this. Do not contemplate doing this with builder alone.

sillysocks

Ok will make sure an engineer is involved. Would something like this greatly increase the price of an extension? It's single story and will be under the 40m2 for planning.

sydthebeat

you are legally required to get Local Authority permission to do this.

regardless of size of development

sillysocks

Is this the case even if it is a private drain? From looking online I thought that was only needed if it was a public drain? Open to correction on that though, and would need to get someone to check out which kind of drain it is to be sure.

Philope

I'd divert a new sewer around if at all possible, and remove the old one before proceeding with your build.
Building anything over a sewer or storm drain is extremely bad practice and it will cause problems for you some day.
If it's a public sewer you'll have to get permission to divert it or build over it, and if it's a private but shared sewer, you might have to as well from the parties you share it with / estate management.

sillysocks

This sounds like it's going to get complicated and expensive
Majorly out of space in our house, but can't move due to negative equity. We've the manhole in our garden as well as those pipes. I don't think we would have space to move the pipes as the extension will be going almost to the boundary on the side where the pipes are.
We were hoping to get the building done within our budget, which I think it would have been before any pipe issues came up, but now I'm thinking it might be out of our reach if it's going to be as complicated as it sounds.

Philope

sillysocks wrote: »

This sounds like it's going to get complicated and expensive
Majorly out of space in our house, but can't move due to negative equity. We've the manhole in our garden as well as those pipes. I don't think we would have space to move the pipes as the extension will be going almost to the boundary on the side where the pipes are.
We were hoping to get the building done within our budget, which I think it would have been before any pipe issues came up, but now I'm thinking it might be out of our reach if it's going to be as complicated as it sounds.

It's not really complicated at all for any good builder if the levels and fall of the sewer make it possible to divert it.

It's certainly not as complicated as any problem occurring with the sewer at a later date, under your extension, after it's been built.
Then you'll fairly know about complicated and cost.

sillysocks

Will get the engineer and builder to check it out and cross my fingers so!

sydthebeat

sillysocks wrote: »

Is this the case even if it is a private drain? From looking online I thought that was only needed if it was a public drain? Open to correction on that though, and would need to get someone to check out which kind of drain it is to be sure.

it doesnt have to be public, once its shared its subject to this requirement.

water services act 2007


104.—

(1) A person shall not, except with the consent of a relevant
water services authority and following an application for the purposes of this section to that authority, erect or commence to erect,
or cause to be so erected, any structure—
(a) over, or
(b) so close to as to cause a risk to, or interfere with, the structural integrity of or access to,a sewer, drain, water main, distribution system, service connection or related accessories which are owned, controlled or used by another person.

(2) The obligation in subsection (1) shall apply notwithstanding
any provision in any other enactment in relation to control of
development, building standards or practices, or any related
exemptions.

(3) A relevant water services authority may grant a consent under
subsection (1) where it is satisfied that—
(a) adequate access to the pipes and related accessories
affected will remain available for maintenance or
renewal purposes,
(b) human health and the environment are adequately pro-
tected, and
(c) the structural integrity of the pipes and related accessories
affected, and access to water services through them, will
not be adversely affected,
and it may include in a consent such conditions as it considers neces-
sary for these purposes.

(4) Where a structure to which this section applies is commenced
or erected without a consent under subsection (1), or in contra-
vention of such a consent, a relevant water services authority may
by notice to the person who erected or commenced to erect the struc-
ture or caused it to be erected, or to any other person who for the
time being owns the structure, direct that remedial action be taken
within a specified period, including—
(a) provision of such alternative sewers, drains, water mains,
distribution systems, service connections or accessories as
it may specify,
(b) re-routing around the structure of such pipes as may be
affected,
(c) provision of alternative or additional access to such pipes
as may be affected,
(d) demolition or alteration of the structure, or
(e) incidental and related requirements.

(5) A relevant water services authority shall have a right of action
for relief by way of injunction or declaration from the High Court
against any person, to restrain any non-compliance, or direct any
compliance with a requirement of a notice issued by the authority
under subsection (4), and the Court may grant such order as it sees
fit, in such manner as to achieve the purposes set out in subsection
(3), including an order requiring provision of alternative pipes or
related access, re-routing of pipes, or removal or alteration of a
related structure within a specified period.

macadam

What did it cost to move the said manhole I have a similar problem , shared manhole 6' deep with 3 inlets coming into a 9" main, needs to be moved 6'.

sillysocks

Not sure if that is meant for me or the original poster....
We don't need to move the manhole - the manhole is in another part of the garden to where we are planning the extension.
Just to follow up in case anyone is reading this in future. We had an engineer out, he has designed a raft foundation for us and we are going ahead with the extension. The engineer with water services at our local council has agreed the plan and once our finalised plans are drawn up he will give a full sign off to them.

Chrislongford

As an from 1st of January 2014 all sewer/watermains become property of Irish Water. They have a no build over policy. So if you can't reroute it, you won't be granted planning permission. Also no matter what size the building is it is illegal to build over any utility services without planning permission. I'm speaking from experiance. Google Irish Water Longford Extension and theres some news articles on it. If anyone has experianced otherwise id love to hear.

BryanF

Can you post particular phrases used by the local authority thanks

murnettie

macadam wrote: »

What did it cost to move the said manhole I have a similar problem , shared manhole 6' deep with 3 inlets coming into a 9" main, needs to be moved 6'.

Did you ever get it done? Dou have any idea of how much moving the manhole is?