Depth of drainage under driveway

[SarahG]

Our drainage is 600mm under the drive and has been signed off by building regs. We are trying to get our warranty certificate, but they are saying we need some chartered professional to confirm acceptance as it is close to the surface. The building inspector says he can't comment and our architect is retired. What should the depth be, is 600mm acceptable or does it need a concrete top? The connection to our mains is 615mm so was not possible to go lower.

[Russell griffiths]

Put a concrete strip over it. 
the pipe needs to have a good covering of the correct gravel

the concrete needs to be wider than the trench and place it’s load on virgin ground both sides of the pipe. 
look up a drawing for this. 
get it done and send evidence in. 

[saveasteading]

2 hours ago, SarahG said:

has been signed off by building regs

It is quite clearly laid out in the building regs, so if you have done it according to that then you should not need another party to confirm it. 

 

 

 

Edited 4 hours ago by saveasteading

[SarahG]

4 hours ago, Russell griffiths said:

Put a concrete strip over it. 
the pipe needs to have a good covering of the correct gravel

the concrete needs to be wider than the trench and place it’s load on virgin ground both sides of the pipe. 
look up a drawing for this. 
get it done and send evidence in. 

Yes this is an option, the builder as far as they are concerned have sign off and have completed work, so this is extra required for warranty company and will cost at least £1k to pull up drive, cut membrane and lay concrete. Really don't want to pay for that and also don't want to rip up my new drive for something that building officer says I don't need.

 

@saveasteading we have a 600mm deep trench, so if 300mm is what we need we are already double that. I will call warranty provider in the morning and see if I can talk to someone, they never seem to call me back.

[Mr Punter]

Sounds like your warranty company are being dickheads.  Is this Protek?