Hi all
I've not done a search on this topic as it's quite bespoke and regards a quotation I've been given for a driveway installation and dropped kerb.
The contractor in question is N. A. Georged Limited of Frome Somerset (anyone used them before?).
Anyhow. I've no reason to doubt that the quote is incorrect but just wanted a sanity check on the figures quoted.
the area to be covered is approx 95 sqm's.
I've been quoted the following figures for that area:
Excavate and remove Spoil = 54tonnes @ 225mm deep
Granular sub base type 1 = 35tonnes @ 150mm deep
lay kerbs and concrete around border to driveway = 35 metres (39 edging kerbs)
Tarmac to finish driveway and entrance:
20mm dense base course = 13tonnes @ average 50mm deep
6mm dense wearing course = 6.5tonnes @average 25mm deep.
I won't quoted the final figure because I don't believe it would be fair on the company (because I'm not quoting other contractors).
I just want a feel for the measurements and weights quoted...do they match up to the area specified and are the depths/materials detailed enough or should I insist on a more detailed quote?
One more thing, the sub base of 150mm is a prerequisit form my housing authority whomb I purchased the house from. They have say in any changes made to the property for the next few years under the Right To Buy law. Thought I'd mention this because I have previously read on here that a 100mm sub base would be fine for a residential drive. It's the housing authority and NOT the contractor who has stipulated this.
Cheers
Wayne
Do these costs/measurements sound right?
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84-1093879891
Excavation - this is normally done by volume, rather than weight.
95m² @ 225mm = 21.4m³ @ c.1.8t/m³ = 38 Tonnes
However, if concrete is involved, the density figure rises, and also, there may have been an allowance for spread.
Sub-base -
95m² @ 150mm = 14.3m³ @ 2.0 t/m³ = c.29T
Bitmac:
Binder (base) course
- 9m² per tonne @ 50mm compacted depth
hence 95 ÷ 9 = c.11T
Surface (wearing) course
- 17m² per tonne @ 25mm compacted depth
hence 95 ÷ 17 = c.6T
150mm for a sub-base is not exceptional. I use the 100mm figure on the site as a minimum recommended sub-base depth for a residential driveway serving typical family cars (not 4x4s, vans etc), although in several places it is acknowledged that 150mm is often used.
95m² @ 225mm = 21.4m³ @ c.1.8t/m³ = 38 Tonnes
However, if concrete is involved, the density figure rises, and also, there may have been an allowance for spread.
Sub-base -
95m² @ 150mm = 14.3m³ @ 2.0 t/m³ = c.29T
Bitmac:
Binder (base) course
- 9m² per tonne @ 50mm compacted depth
hence 95 ÷ 9 = c.11T
Surface (wearing) course
- 17m² per tonne @ 25mm compacted depth
hence 95 ÷ 17 = c.6T
150mm for a sub-base is not exceptional. I use the 100mm figure on the site as a minimum recommended sub-base depth for a residential driveway serving typical family cars (not 4x4s, vans etc), although in several places it is acknowledged that 150mm is often used.