Build over agreement for sewer

12 Mar 2010
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United Kingdom
We're going to need one of these from Thames Water for an extension. Just looking for info in advance of getting in touch with Thames Water

1. What do they tend to cost
2. Will we require an accessible manhole cover inside (there isn't the fall to re-route the sewer to the end of the extension.
3. What length of time are TW likely to take to give the agreement?
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My local council (Enfield) gave me the go ahead.
I havnt left an inspection cover, but it is measured & photographed for id acces is required.
What with the camera technology available today, that should not be required
The cost is whatever your local WA charges for the application ... £200 and something for smaller sewer diameters, and more for larger ones

You will also need a CCTV survey before and possibly after the work is complete - only via one of the cliquey band of contractors "approved" by the WA

Whether you require a sealed cover internally will depend on the b/regs requirement for the drains, and nothing to do with the build-over application

Time is normally 2-3 weeks after the CCTV and lodging the application with all the required details ... but some work quicker if you ask nicely
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Do you definitely have a public sewer on your property and if so what class of sewer is it.

If there is a branch or change of direction in the sewer requiring a manhole then you cannot build over it, full stop, therefore a sealed cover is not acceptable anyway.

If the manhole is covering an open straight run or a branch solely from your property, then it possible to replace the open run with closed pipe, but this would mean re-routing your branch to enter the sewer outside of the building.

What sort of sewer do you have if it is less than 160mm then the rules are more relaxed, is it a section 24 sewer or something more major, how deep is the invert of the sewer.

There will almost always be away to re-route the sewer, as at some point it will enter the main deep sewer so fall won't be a problem, however cost might be.

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