m.o.t. type 1???

[TheOriginalTableLeg]

I am in the process of ripping up my driveway. 18m long x 3.7m wide, it basically consists of 2x 100mm thick strips of concrete approx. 90cm wide.

These sit straight onto the dirt.

I have some questions regarding this project.

1, Given that these have been like this since the house was built, would I still need to compact the earth? A car has been driven up and down the driveway since day 1.

2, Having researched this project, I am of the understanding that I need to use 'm.o.t. type 1' as a sub base and also a weed control fabric.
Given that I have all this concrete I am breaking up could I not just reuse that as the sub base? and if so, what thickness would it need to be?

3, Just to clarify the fabric lining goes directly under the gravel? Would it not puncture easily when driven on and the gravel is then pressed down onto it? Do I need to use sand between any of the layers?

4, Gravel calculators..... Again researching this give various recommendations as to the thickness of the gravel required. It appears I should aim for approx. 50mm of gravel as the top layer.

Thanks in advance to anybody who answers.

 

[PrenticeBoyofDerry]

You'll find most of your answers here
link
http://www.pavingexpert.com/faq_subbase.htm

 

[TheOriginalTableLeg]

Does 19 tonnes sound right ofr a sub base of mot1 at 100mm?

Sounds a lot!!!

 

[Hugh Jaleak]

19 tonnes may sound a lot but is actually one load on an 8 wheel lorry, and when tipped wont look much! Probably find it doesnt go far either when you start spreading it out at 100mm deep.....

 

[TheOriginalTableLeg]

Thanks for that. With this kind of load I guess it would be best to get it from an aggregates/quarry type place?

Any idea what a load like this would cost???

 

[hotrod]

Hi OriginalTableLeg, not sure where the 19 tonnes comes from? I calc your requirements as:-

18m*3.7m*0.1=6.66m³
6.66m³*1.8=11.98tonne

So call it 12 tonne. The quarry I know will do 10 tonne loads direct (which is in fact half load but they just send in smaller wagons). Cost at a guess, anything between £150 to £200 dependent on haulage cost and half load premium. Then just get your extra 2 tonne from the local merchants in a grab bag or loose.

 

[TheOriginalTableLeg]

Sorry Hotrod, I have a 2nd patch that I am doing the same to as well. It is 5.7m x 5.1m.

I believe the total to be approx. 19 tonnes.

Thanks for the reply.

 

[Thermo]

you want a minimum thickness of 150mm mot for a driveway, well compacted. you also need to allow for that face that it will be compacted in your calculation. 50mm for the gravel is about right.

 

[TheOriginalTableLeg]

Thanks Thermo.

I have read the 'paving expert' site in relation to gravel driveways and it appears that the use of a Fabric weed control membrane is unnecessary
for a gravel driveway.

It appears to have some good uses for other things but from what I can see is not recommended.

It implies that the subase and then subsequent layers above this should prevent most weed growth anyway.

Any comments on this? I do not want to spend out money that could be a waste of time as well.

 

[r896neo]

you will find that the only weeds on a properly prepare gravel driway will be small ones growing in the leaf=mould/dirt between the gravel, certainly not coming from below.

 

[TheOriginalTableLeg]

you will find that the only weeds on a properly prepare gravel driway will be small ones growing in the leaf=mould/dirt between the gravel, certainly not coming from below.

So therefore is the 'weed control fabric lining' worth it?

If its only small weeds then a 6 monthly coating with a good weed killer should see them off. But then again if the fabric would prevent them completely then it could be worth the extra cost.

???

 

[r896neo]

no i mean that the fabric is useless because the weeds grow in the detritus that over the years collects on top of it. It though is designed to stop weeds coming up from below. which frankly they don't do on a properly contructed drive.

 

[TheOriginalTableLeg]

no i mean that the fabric is useless because the weeds grow in the detritus that over the years collects on top of it. It though is designed to stop weeds coming up from below. which frankly they don't do on a properly contructed drive.

I see

Thanks for explaining that.