Which method of drains rectification?

[SilverShadow]

Hi there,

 

Here to gather valuable insights from you gurus & those 'in the know' 😁

 

A CCTV survey has shown the 110mm clay waste drain (running adjacent to the house) has failed at several areas along it's 14m length between manholes (offset joints, up to 1x pipe diameter thickness). The drain is private, 7m of which lies under a concrete pathway, upon which is also a 2m side-porch. It has 2 pipes joining for kitchen/bathroom drainage (under concrete path)

 

Seems like there are a number of options available:

 

• Replace: excavate & re-lay

• Repair: drain sleeve lining patch

• Replace: trenchless (eg: moling, pipe bursting)

• any other suggestions

 

Ideally prefer not to rip up the concrete pathway / porch, unless the costs & merits of doing it really make sense

 

Does anyone have any clues as to cost £/metre, which would give the greatest longevity?

 

I'd love to know your thoughts / experiences / costs for trenchless work, as this seems least intrusive (unless it costs a bomb)

 

Many thanks 

 

[markc]

If it was just a straight pipe a drag buster and pull in new pipe would be most cost effective way to save the path but still not cheap. Your big problem is the two connections as these cannot be done without access.

I would sacrifice the path to save the porch (assuming the pipe isn’t concreted in you will be able to get a new pipe under the porch by digging access pits either side.

not easy to price but a gang of 2 with a digger should do it in 3-4 days depending on access and obstacles etc.

[SilverShadow]

Thanks MarkC - appreciate it's hard to know without seeing it 1st hand

 

Tbh, I think we'll have to excavate around the connections, regardless of resolution.

 

What would be your 'gut instinct' as regards very approx price? I'd read online, that moling might be possibly £800-£1200, for this sort of job? 🤷‍♂️

 

Would that be for drag buster or full excavation?

Edited November 26, 2022 by SilverShadow

[markc]

2 hours ago, SilverShadow said:

Thanks MarkC - appreciate it's hard to know without seeing it 1st hand

 

Tbh, I think we'll have to excavate around the connections, regardless of resolution.

 

What would be your 'gut instinct' as regards very approx price? I'd read online, that moling might be possibly £800-£1200, for this sort of job? 🤷‍♂️

 

Would that be for drag buster or full excavation?

Hi, yes you will have to excavate the connections. Moving and dragging are very different. Mole is usually air powered, starts from a excavated hole and basically hammers it’s way through soil and pops out in another excavated hole at the other side of the road etc. dragging is used where there is an existing clay or iron in larger machines, a cable or chain is passed through the existing pipe and a winch pulls a cone shaped ‘buster’ through and a new pipe behind it.

if the length to be busted is only a few metres we did one with a home made cone, length of chain, taped the new pipe behind the cone and pulled it through with a mini digger. But if you allow 800-1000 for someone to do it you won’t be far out … speak to someone at your local utilities contractors or council depot, they always know “someone”  

[Dave Jones]

relaying path is DIY job  cheaper than moleing.

 

 

[SilverShadow]

14 minutes ago, Dave Jones said:

relaying path is DIY job  cheaper than moleing.

 

 

Cheers Dave 👍

 

we're hoping not to exceed the £2-3k mark, to get the 14m drains replaced 

 

Depth of the pipe is up to 1.1m, if that makes a difference, as to whether to go via excavation/ trenchless 🤷‍♂️

 

Our approach may depend on whether we have to rip the porch down tbh

Edited November 26, 2022 by SilverShadow

[Dave Jones]

good luck with that. 

 

digger hire, muck away, stone, pipe, relay slabs. Someone who knows what they are doing  to do all that.

 

Be looking double what you are budgeting.

 

Take out the drains insurance with british gas or whoever, live with it until feb. Please ignorance and make a claim.

 

 

[SilverShadow]

1 hour ago, markc said:

Hi, yes you will have to excavate the connections. Moving and dragging are very different. Mole is usually air powered, starts from a excavated hole and basically hammers it’s way through soil and pops out in another excavated hole at the other side of the road etc. dragging is used where there is an existing clay or iron in larger machines, a cable or chain is passed through the existing pipe and a winch pulls a cone shaped ‘buster’ through and a new pipe behind it.

if the length to be busted is only a few metres we did one with a home made cone, length of chain, taped the new pipe behind the cone and pulled it through with a mini digger. But if you allow 800-1000 for someone to do it you won’t be far out … speak to someone at your local utilities contractors or council depot, they always know “someone”  

Thanks again MarkC for your sound advice 😁

 

May I ask, what the £800-1000 estimate represents please? (a small length, 7m, or the full length 14m)

Edited November 26, 2022 by SilverShadow

[SilverShadow]

2 minutes ago, Dave Jones said:

good luck with that. 

 

digger hire, muck away, stone, pipe, relay slabs. Someone who knows what they are doing  to do all that.

 

Be looking double what you are budgeting.

 

Take out the drains insurance with british gas or whoever, live with it until feb. Please ignorance and make a claim.

 

 

I did see Homeserve do something similar. Just wasn't sure if it includes waste drains outside the property

[markc]

10 minutes ago, SilverShadow said:

Thanks again MarkC for your sound advice 😁

 

May I ask, what the £800-1000 estimate represents please? (a small length, 7m, or the full length 14m)

Hi, I was thinking for someone to pop in and get you 2-4 metres under the porch with you digging access pits beforehand. Everything under the path is definitely open trench or you are looking at a lot of money

[SilverShadow]

Thanks for the suggestions guys. In the end we opted not to go ahead with the house purchase & won't need to worry about it

 

Have a great Xmas all 😁