How much MOT hardcore do i need ?

[shd1970]

Hi there,

Can anyone confirm how much MOT hardcore i would need please for the following dimension on my driveway :

7m x 4.5m
I need a compacted/finished depth of 50mm

I already have a solid hardcore base and this layer is simply bring the overall level up sufficiently to then gravel straight on top

I've found a number of online calculators which have returned everything from 2.6 bulk bag to 4.5 which seems to be a pretty wide and wild range !

Many thanks in advance !

 

[denso13]

Just over 3 tonnes

 

[shd1970]

Just over 3 tonnes

thanks for the quick reply denso !

do you use a particular online calculator or if not, can you educate me with your maths please ?

my head was telling me get 2 bags first, rake it around and if i still needed more, to then order that separately as its free delivery

 

[Bouy]

thanks for the quick reply denso !

do you use a particular online calculator or if not, can you educate me with your maths please ?

my head was telling me get 2 bags first, rake it around and if i still needed more, to then order that separately as its free delivery

Sub base stone, mot and scalpings calculator (source4me.co.uk)

but depends on type/density of stone you are using

 

[denso13]

7 x 4.5 x 0.05 = 1.575m³

roughly two tonnes in a m³, therefore 1.575 x 2 = 3.15 tonnes.

Remember a large bulk bag is short of a tonne, normally.

 

[blup]

I would use this guy's calculator, he knows what he's talking about:

Sub-bases | Pavingexpert

Blup

 

[Charlie George]

Just over 3 tonnes

Just to make sure you know, that would be 4 bulk bags
Edit Just seen your post above

 

[denso13]

I would use this guy's calculator,

I think he uses mine

 

[shd1970]

Bouy / Denso / Blup - cheers guys, much appreciated !

All coming in just over 3t

 

[denso13]

All coming in just over 3t

I've used the same calculation for many years for hardcore and concrete, basically m³ x 2.

Rule of thumb for decorative chippings is that 1 tonne will cover 10m² at 50mm deep.

 

[shd1970]

I've used the same calculation for many years for hardcore and concrete, basically m³ x 2.

Rule of thumb for decorative chippings is that 1 tonne will cover 10m² at 50mm deep.

awesome, thanks again denso !

 

[shd1970]

I've used the same calculation for many years for hardcore and concrete, basically m³ x 2.

Rule of thumb for decorative chippings is that 1 tonne will cover 10m² at 50mm deep.

i meant to ask denso, what's your thought on the percentage compaction ?
will 100mm compact to 50mm or is that optimistic ?

 

[Bouy]

If you had a bulk bag of MoT do you think if you stamped on it , it would reduce to half its depth? 10 -20% compaction at a gusstimate but your ground beneath may also compact

 

[denso13]

will 100mm compact to 50mm or is that optimistic ?

No, 5-10mm if you're lucky. As above it depends on the subsoil as well, soft ground will make a difference.