Free draining version of MOT 1?

[Alan Ambrose]

I read about MOT 3 (e.g. here https://www.cloburn.co.uk/what-are-the-3-types-of-mot-aggregate-and-which-would-be-best-for-my-project/ ) but yet to find a local supplier.

 

Supposing you wanted a fairly free draining version instead of a standard MOT spec e.g. under a driveway sitting on sticky clay, what would you use?

[Thorfun]

We had type 3 specified for our driveway to allow it to drain freely. At the start of our journey we dug out and put the subbase of type 3 down using virgin type 3 granite. Was really expensive!

 

later in the build when the ground workers were backfilling the basement they used zero-fines hardcore which was loads cheaper and still free draining!

 

speak to an aggregate company and ask if they can do fines-free recycled hardcore at the required specified size (think it’s 5mm - 40mm for type 3)

[Great_scot_selfbuild]

Following - I'm searching for similar grading of stone for under driveway and for the tree root protection.

 

Do you have a design you're working to yet? (I'm waiting for structural engineers to reply atm)

[jack]

See if you can find recycled railway ballast. We used it under our raft foundations. 

 

Make sure you get the cleaned version.

[Alan Ambrose]

I'll spend some more time talking to the local aggregate suppliers next week when everyone is back. In the extreme, can I make up my own aggregate, say with a mix of stone, shingle and sand?

[Alan Ambrose]

>>> Do you have a design you're working to yet?

 

Yes, several, but they're all generic and specify MOT1 and I want them to be free draining.