Kitchen extension and sewer line

[Little Joe]

We are in the process of buying a second hand house and we want to plan an extension (less than 40 sqm) to the rear of the house. The main sewer line runs across the back garden with an access point and manhole cover in the area we would like to build.

What are our options if we want to build in this area? Are we restricted from building over this access point?

Any feedback would be much appreciated.

 

[baldyman27]

By 'main sewer' do you mean its the main sewer for just this particular house or is it catering for a number of houses? If the former, there should be no problem diverting it once you have sufficient falls, if the former it could prove more difficult.

 

[Little Joe]

The line appears to run across the back of a number of houses, each with its own access point. My problem is whether it is possible to relocate the access point and also the level of work required to do this, or is it just not recommended. If it is not possible to build in this area it restricts the type of extension we can build.

thanks for the information.

LJ

 

[baldyman27]

This is just my tuppence but I'd say by the sound of it you'd be better off not interfering with that main sewer. Would be fairly costly, depending on the size, and would be involving the council a lot more. You wouldn't, or shouldn't be allowed to build on top of it as is. Probably worth asking a local engineer for his opinion though.

Just re-read your post, if its only an access point that's in your way then its probable that the main sewer is outside this again, possibly outside your site boundary, in which case there should be no problem moving the access point. You can build on top of your own private connection no bother.

 

[Little Joe]

Interesting point. I will be checking this out over the coming weeks.

Thanks for the advice.

LJ

 

[sallins]

You need to consult a civil engineer familiar with sewers. I would be surprised though if a large sewer runs through the middle of your garden -this would be very poor practice preventing later expansion. Suggest you also look at neighbouring properties and check if they have extensions in line with your own plans. If so it would likely indicate that the problem may not be major. You should not consider building over a manhole. Am a retired Charterd Engineer by the way.

 

[Sconhome]

I have reently completed an extension where two access covers were uncovered within the area that was to be in the building. The property owner had plonked a patio over the access covers years previously and thankfully did not need to gain access at any time.

We could not divert the sewer around the structure as the pipe falls were inadequate for this purpose, and had no option but to build them into the structure. Once your engineer designs a prestressed lintel to bridge your pipes in the rising walls you risk no damage to pipes.

The internalised access covers can be replaced with sealed units which have a mini-gasket similar to an S-bend to trap venting gases. The covers are bolted down, thus preventing nasty smells but retaining access to the pipework in case of emergency. I picked up the units in Galco steel, go for the aluminium covers, very pricey, but much cheaper than stinky rooms and blocked pipes!