Block paving paths?

[Ralfy]

I am in the process of digging out my driveway to a minimum depth of 200mm. Is it necessary to dig out paths that will also be block paved, but only subject to foot traffic, to the same depth?

[Dave_L]

I take it you are digging out by hand?

Are the pathway areas big? If not, it hardly seems worth varying the depth.

[Rich H]

For a narrowish path in a lawn (and depending on the subgrade) I'd be tempted to put down 50mm MOT, 50mm sharp sand/cement screed and hand consolidate the blocks on that. 150mm total dig out.

[Tony McC]

I'll spoil the party by re-stating the case for sub-bases never to be less than 75-80mm depth, if only because of the reasons outlined here

When there's less than twice the max particle size, the sub-base material acts more like "fill" than a structurally sound load-bearing layer. So, even for a garden path, I'd stick with 100mm of sub-base.

[Ralfy]

I am digging out by hand, but the total area isn't too big and it keeps me fit. The pathways run in front of and down one side of my bungalow (about 12m x 1m wide). I will dig out as deep as I can manage. I am down to about 150mm already and have already found the pipes for the 3 main services (the property is on a slight incline from the road, so they are probably a good bit deeper there). Is it advisable to dig beneath these?

I am taking photos as I go along and keeping a record of costs and time. I will post these once the project is complete.

I am sure I will be back for more advice as the project progresses over the next few weeks (or months).

[Tony McC]

No: don't underdig the services at this stage. Leave the sub-grade in place to support the cables/pipe. Contact the relevant utility company and ask them to drop the services. they'll undoubtedly have some crappy excuse why they can't but make a nuisance of yourself.

If the UCs won't drop/relocate the services you could try encasing them in a split duct yourself, ensuring they remain fully supported as far as practical, otherwise it's a matter of cushioning them with grit sand and working around/over them as carefully as possible.

[Dave_L]

Split ducts - what a great invention they are - we had to duct some street lighting cables that were adjacent to a 4 way BT duct that we had to encase in concrete to facilitate a crossover - we collected them from the local power company's yard and kept a few to ourselves - they have come in very useful on a few jobs since.

Agree with Tony - leave the services well alone - any disturbance could cause leaks etc - but I guess if the pipework in in that state, it is better leaking/failing now rather than later when all the surface work is complete.........

I've found the gas board to be the best at replacing corroded/old/dodgy looking pipework under driveways etc.

[Ralfy]

I had a man from National Grid out to check the Gas Pipe. He told me that the pipe is a recent connection that has been run through the old metal pipe and that it is well protected. The electric cable is encased in hard plastic, so I just have to be careful not to cut into it with a spade. The water pipe is copper running from the meter just inside the boundary to the house. I have spoken to Anglian Water about it and they said I could get a plumber to replace and lower it at my expense. They also suggested lagging it to protect it from frost.

As the 3-4m length where the pipes are 150mm from the surface is only subject to foot traffic, I think I will leave them where they are and just be very careful when adding the hardcore and paving.

Any specific preparations I should make or other suggestions gratefully received.