Should I use roadbase or blue metal for paving base?

[MeMo]

I am putting in paving and have been getting conflicting opinions on using road base/crushed rock or stone dust/blue metal as my bottom layer (with bedding sand on top). Which should I be using and is there reasons why each may be better in different circumstances?

[MitchellMc]

Hi @MeMo,

As long as you use a larger particle as the base and then cover it with a finer particle, it doesn't make much of a difference what those two particles are. If you were creating a driveway that will bear the weight of cars, you might need to put more thought into the materials used. It's fairly common to use a road base and paving sand. The only reason you might like to go for a larger base like blue metal/drainage gravel is that it's 10-20mm in size and would provide better drainage if the area has issues with standing water when it rains. However, typically the smaller the particle, the better the compaction you can achieve.

Here's a helpful step-by-step guide: How to lay paving for a path. You'll see @Adam_W, a qualified landscaper, uses roadbase and sand in this article.

How you compact the area can be more important than the base materials. At a minimum, you'll need a hand tamper, or if you're not looking for a major workout, we hire mechanical compactors. Remember your PPE gear, including gloves, enclosed leather shoes, and safety glasses, when laying and handling your paving.

Please let me know if you have any questions.

Mitchell