Digging trench for new water pipe.

[stevemff]

Hi,

I have my plumber coming in next week to finish off some work. Part of what we wanted to do was run a new pipe in from the stop cock at the front of our drive via a new route under the front bay.

Since his back isn't up to it I agreed to dig the trench since I need to get a mini digger in for another job anyway.

My question is how to remove and reinstate the tarmac part of the trench. If you look at the house from the street on the left is a tarmac drive about 6 or 7 feet wide running back along the side return with the rest of the width of the frontage as garden.

I will be taking a diagonal from the stopcock in the centre-front of the drive. It's about a 20ft or so trench in total but the first few feet will be driveway. I was thinking of angle grinding out neat sections of tarmac so I can effectivly put them back like lego and then sticking them back in (no more nails? ). Is that stupid and unrealistic? Will I have to just get that bit of the driveway re-tarmaced when we're done?

Thanks,
Steve

 

[Hugh Jaleak]

Cutting the sides out initially is a good plan, depending on condition of existing surface. (If material is in poor condition then it's likely to crumble into stones anyway.) I doubt you'd be able to reuse the pieces though, difficulty would be getting them to stick back down. Bitumen by nature is very sticky, the whole nature of coated stone is the bitumen binds the aggregate, once compacted and cooled it goes off to form a very durable surface.

When laid, the material will (should!) also have stuck solidly to the hardcore under the base course, so it would likely be nigh on impossible to get it to sit back in the trench flush with the edges either side. There is also the issue of frost damage, should water get in the joints and freeze it will slowly start to wreck the surface. IMO you would be better getting it properly reinstated with fresh material and joints sealed correctly if you want it to last, otherwise you may find you'll need to repair a lot bigger area after a harsh winter has taken it's toll....

 

[noseall]

Just to add...

If you encounter anything other than small granular material and unless you are an exceptional digger driver, you are likely to spoil the edges of the tarmac in any case.

Also, most peoples' front drives are very 'busy' underground so go very slowly and be vary wary.

 

[taz123]

Not sure if this is possible in your case but have you considered the use of a mole(moling)?

 

[mattice]

Have a similar job, I'll be doing by hand, grinder to create straight edges, and topping with cold lay tarmac and compacting. I'll be replacing my drive in 3-5 years so hopefully it'll do the job!

 

[stevemff]

Thanks for the advice guys, I thought it might be a bit unrealistic just to cut them out neatly but you never know for sure till the first time you try. I've seen those indusstrial scale molers before and they are pretty cool but just a digger for me this time.

As Noseall mentions my big concern is hitting a drain or similar under there. I'll be checking out the directions when I take up the manhole cover so hopefully I should have a pretty good idea where it runs in the driveway. I'm hoping there isn't too much buried in the garden but I'm concerned where the gas main etc is. I'm not sure how I can locate that but I'll read up on it.

Cheers

 

[Hugh Jaleak]

I wouldnt worry about the drains, you can soon repair those! Gas/electric should be your concern, hitting them at best is expensive, at worst could be fatal..... I would strongly advise you dont go anywhere near with a machine until you are 110% certain where they are, and then hand dig carefully to expose the relevant section. (I've seen someone put a digging fork through a plastic gas service whilst trying to clear surrounding earth so the machine driver could see it..... )

 

[stevemff]

Just an update to say all went well Bobcats are awesome and no cables hit. Did come across a clay pipe that we couldn't figure out at first but it turned out to be a vent pipe for the drains.

Took three times as long as we thought of course but other than that no problems. Thanks for the advise

 

[noseall]

I thought Bobcat made skid steer loaders...?

 

[Hugh Jaleak]

Bobcat make mini diggers, telehandlers and a few other bits as well, now part of Doosan (formerly Daewoo) who make the bigger stuff.

 

[noseall]

Bobcat make mini diggers, telehandlers and a few other bits as well, now part of Doosan (formerly Daewoo) who make the bigger stuff.

I'm sure they do Hugh just like JCB make electric drills too.

I was being generic with a hint of synonym.

I would have phrased it "those mini excavators are awesome" rather than use the synonymous relevant word or brand "Bobcat" if you get what i mean.

It would be like saying "Hoovers are great aren't they", whilst referring to their washing machines whilst everyone else is thinking vacuum cleaners.