The Brew Cabin

Oh dear!

I spent the weekend excavatig 22 m2 of patio area down 180mm!

I think that was a bit deep now! What's the cheapest suitable method for me to raise it back up to a sensible level for the bedding layer?

I feel really stupid now!

Id cut my losses and fill it up with mot/crusher run. At least you would know its going to be soild and last. I would not try and put old brick or broken flags down first. This may create voids that would allow the sub-base to settle unevenly in time, that would effect the finished suface.

Spot on, agin, Ken!

Whenever levels need raising, it should be done with granular material, in layers not exceeding 225mm, each comnpacted nefore placing the next. Now, obviously, this slight overdig isn't going to need multiple layers of fill, so I make those comments for other readers, but the same principle applies - use a quality inert material, preferably a graded Type 1, Type 2 or crusher run material, and make sure it's really well compacted before you commit your bedding and paving layers.

Thanks guys.

I should raise it up by 90 mil then?

Yes, that'd be fine, assuming you're using 40/50mm flags and planning to use a 40/50mm deep bedding layer.

Don't forget to allow for falls, and build those falls into the sub-base layer, so that the bedding layer is of a (fairly) uniform depth.