diverting sewage for rear extension

newbridge

Hi,
I am in process of planning a rear extension(3m) for my semi-detached house. The foul sewer runs across(left to right) the rear of the house and has a man-hole too which would require moving as I don't intend to have it inside as one of my friend suggested to me.


1) Once option is not extend to full width(9 meter) but leave 1m on one side for man-hole. So that would mean only moving the man hole across to the end.


2) Build a full width rear extension, which will require two T junctions under new flooring, such that new man-hole can sit further out towards back in the garden.


Are T-junctions without man-hole allowed?

What do you think the cost difference would be between 1 and 2?



Am trying to do this on tight shoe-string. Appreciate your answers and thoughts.

anselld

Option 2: are you seriously suggesting creating four bends in an otherwise straight pipe so that you can have a manhole in the garden? That is ridiculous.

Option 1, or you have a sealed manhole inside.


Is the current building 9m wide at the back then? The 3m PD rights (if that is what you are thinking) is 3m from the back of the original building following the line of the original building. You can only build 9m wide if the original building is 9m wide and flat at the rear.

suki1964

There’s nothing wrong with having the manhole inside , my last house , being a terrace, we had no option. You forget that it’s there after a while

newbridge

Thanks for your reply

anselld wrote: »

Option 2: as you seriously suggesting creating four bends in an otherwise straight pipe so that you can have a manhole in the garden? That is ridiculous.


For full width extension, current straight pipe will be buried under the new extension. I thought 1 manhole would be required just in case someone needs to put a rod during blockage and would need diverting.




Option 1, or you have a sealed manhole inside.


Is the current building 9m wide at the back then? The 3m PD rights (if that is what you are thinking) is 3m from the back of the original building following the line of the original building. You can only build 9m wide if the original building is 9m wide and flat at the rear.

Yes the current building is 9m wide and flat, so 3mfrom back of original building.

newbridge

suki1964 wrote: »

There’s nothing wrong with having the manhole inside , my last house , being a terrace, we had no option. You forget that it’s there after a while

Would it not spoil everything when sewer gets blocked and maintenance guys need access? Also we are thinking of tiling in the extended kitchen.

suki1964

newbridge wrote: »

Would it not spoil everything when sewer gets blocked and maintenance guys need access? Also we are thinking of tiling in the extended kitchen.

You buy a double sealed cover and tile on top of that. We had laminate back in the day and the boards were cut to fill the lid of the cover

Yes you see the rim and the lifting ring but it’s the cheapest option. I covered mine with a rug. A dining table or any bit of furniture will hide it


We even had to move the soil stack to run through the roof space of the extension

With waste, you want as few bends as possible, esp if it’s not just your waste passing by

Davesnave

suki1964 wrote: »

You buy a double sealed cover and tile on top of that. We had laminate back in the day and the boards were cut to fill the lid of the cover

In England And Wales it's against building regulations to build over an inspection chamber now. Indeed, if you want to build within 3m of a shared drain, then you'll need a building regulations sign-off of the work and the approval of the local water authority to carry it out.

Sorry, but we are no longer 'back in the day.' Judging by what was proposed with the right angled bends, perhaps it's just as well!


Edited to add: You may be able to get a build-over agreement from the water authority. I did, but that was also some time ago now. If so, they will make their requirements clear, regardless of your shoe strings. It might be possible to do as I have here with inspection chambers at either end of the extension. After all, 9m is not a huge length to rod in a straight line, if needed.

anselld

See Page 7, Figure 2....
https://www.thameswater.co.uk/-/media/Site-Content/Developer-Services/Guide-to-building-over-or-near-a-public-sewer.ashx

Cakeguts

Does this sewer only serve your house? Some semi detached houses share sewers. If it runs across your back garden where does it go to meet the main sewer in your road?

suki1964

Davesnave wrote: »

In England And Wales it's against building regulations to build over an inspection chamber now. Indeed, if you want to build within 3m of a shared drain, then you'll need a building regulations sign-off of the work and the approval of the local water authority to carry it out.

Sorry, but we are no longer 'back in the day.' Judging by what was proposed with the right angled bends, perhaps it's just as well!


Edited to add: You may be able to get a build-over agreement from the water authority. I did, but that was also some time ago now. If so, they will make their requirements clear, regardless of your shoe strings. It might be possible to do as I have here with inspection chambers at either end of the extension. After all, 9m is not a huge length to rod in a straight line, if needed.

This wasn't "back in the day" , it was fully covered by the building regs, DS checking every step of the way and signed off

The double sealed lid was built so you could camouflage it into the floor, same as what I have outside right now ( only that's pavers and it takes two people to lift)

So the manhole was built up to reach the new floor level and the floor was laminated and the boards were cut to fit the lid so the floor didn't look "bad"

gettingtheresometime

Get yourself a good water engineer who'll draw up the plans if you need a S185 for the sewer diversion & do the whole application for you or they can advise you whether a build over application can be done