Advice re estimating groundworks cost & logistics

[RomanAbramovich]

Planning a sizable extension, essentially a rectangle 5m x 10m.

Job is to excavate a trench for foundations, 5m by 10m by 5m, 600 wide and 2m deep (there are some big old tree close by). The fourth side of the rectangle is the existing house.

I make that 24 cubic metres of soil, muck away, then 24 cubic metres of c20. Fortunately site access is really goo so mixer can reverse uo to the trench and dump.

Approx how many tonnes does the soil equate to? Assuming grab lorry will be the quickest and most cost effective muck away - anyone have any experience of load/cost per lorry load? I recall how soil 'bulks up' once out the ground.

Should I get a 1.5 ton digger for this job, or is that too small? (planned to hire man and digger).

Finally, have assumed 100 quid per cube of concrete, in total 2400 quid delivered.

Any advice of your recent ground works experiences much appreciated.

I have a ball park figure in mind of 4000 for the job.

This is south west (east devon)

 

[ban-all-sheds]

Approx how many tonnes does the soil equate to?

36 - 60?

Assuming grab lorry will be the quickest and most cost effective muck away - anyone have any experience of load/cost per lorry load?

Not in Russia, I suspect.

Phone around in your locality - that's the only way to find out.

Finally, have assumed 100 quid per cube of concrete, in total 2400 quid delivered.

You did tell them they'd be delivering to Russia? Surely if you phoned Russian suppliers they would quote a price in Roubles?

This is south west (east devon)

Has Putin got that far west with his annexations? Must have missed that.

 

[noseall]

I would be using a 3tonne digger and a 1tonne dumper.

It will take 3-4 grabloads to remove the spoil, or 4-5 if you need to remove any oversite spoil. We pay £150+vat up here for grabs.

We pay £90 per cube for 'mixamate' type delivery but expect to pay less for 6m drum loads.

Can a lorry access all the way around the trench and without collapsing any sides? You must have a good concrete road or similar all around the trench yes? If not factor in a concrete pump.

 

[RomanAbramovich]

Approx how many tonnes does the soil equate to?

36 - 60?

Thats useful to know, cheers.

This is south west (east devon)

Has Putin got that far west with his annexations? Must have missed that.

My mate Vlad tipped me off that the south west of england is the next port of call for our money laundering compatriates - so expect to see property prices double and mega yachts off the coast at lyme regis and exmouth some time soon.

 

[RomanAbramovich]

I would be using a 3tonne digger and a 1tonne dumper.

It will take 3-4 grabloads to remove the spoil, or 4-5 if you need to remove any oversite spoil. We pay £150+vat up here for grabs.

We pay £90 per cube for 'mixamate' type delivery but expect to pay less for 6m drum loads.

Can a lorry access all the way around the trench and without collapsing any sides? You must have a good concrete road or similar all around the trench yes? If not factor in a concrete pump.

The site is currently tarmac'd, which is useful (nobody likes working in ankle deep mud for weeks - been there, hated that) and minimises oversite spoil. No, a lorry won't be able to access the trench from all sides - however, from previous experience the concrete spewed out at delivery is almost self leveling, so assumed it will flow around the trench, with a bit of manual persuasion? (A guy from lafarge once quoted me for self levelling concrete delivered, bit more expensive but didn't have any advantage on the job in hand, so declined it).

Back to the estimate, would the following be reasonable?

Digger + operator, Dumper + operator. 1 days effort = 500 quid?
5 grab lorry loads at 200 per load (50 tonnes in all) = 1000 quid
24 cubes c20 delivered = 2000.

Reckon excavation can be done in one day, or is two days more realistic?

 

[noseall]

If the site is clear, the dumper guy has a close and large dumping ground and you don't hit any cables, pipes or drains then yes, it could be done in a day. If the dumping ground will only hold one lorry load then you are at the mercy of the grab man.

Are there no dividing walls to be dug? What about digging off the internal oversite spoil? You'd be crazy not to deal with this whist the digger is on site. What we do is dig the trench AND remove the internal oversite spoil as we track back.

Even if they mix the conc' like pish, don't expect it to flow like a river around 20m of trenching. You will maul your bo llacks off trying to pull all that around your trench, bearing in mind that you are working way above the concrete level and not down at a comfy (waist-high) level.

P.S. If it starts raining add another grand to your estimate. If it is a clay substrate and it starts raining heavy, add another two grand.

 

[cjard]

Watched my brother do a pour a while ago; for the far side to the site the chute on the wagon couldn't reach he'd piled up the backfill to form a slope to the point the chute could reach, visqueened it and poured onto the visqueen, what didn't flow naturally into the trench got swept..

Apparently health n safety has put paid to the good old days where you could get chute after chute attached to the back of the lorry..

You don't have to come up in concrete all the way. The material costs are lower if you use something like trenchblock (400 of; about 1600 quid with 8inch of concrete vs 2400 for your concrete alone) but you've got the arse ache of laying them, so after factoring in the time value of money/paying someone to do it at a pound a block(?) you're only saving 400 quid. Your builder might be able to think of some way of shuttering the trench economically

 

[cjard]

Even if they mix the conc' like pish, don't expect it to flow like a river around 20m of trenching. You will maul your bo llacks off trying to pull all that around your trench, bearing in mind that you are working way above the concrete level and not down at a comfy (waist-high) level.

Think I'd be tempted to pull it with the digger..

 

[noseall]

A conc' pump takes all the pain away.