Mixed sub base - Half mot1 half recycled

[mcelec]

as my excavation has had to be deeper than expected i will need twice as much sub base, what i was hoping to do to save a few £££ is lay 100mm of recycled then compact it down then lay 100mm of mot 1 on top and compact this down, is this acceptable or should i just be using all mot 1

[Big Phil]

if it is Recycled MOT1 then it should be ok to use as 100% in 2 layers of 100mm. if it's recycled crap being sold as 'sub base' from any old supplier then maybe not, depends on the quality & grading.

MOT1 is a sub base specification (SHW 803 Type 1) that the material must comply with, so be it limestone or recycled it should perform the same. i'd check with your supplier for conformity certification.

[Dave_L]

Decent clean uncontaminated recycled material on a private driveway will be absolutely fine.

If you are having to go down deeper, some bigger stuff would be good - 80mm down would suit then the final 100mm with type 1 as you say.

It'll want a good thumping down though!