Base for Block Paving

[planemad]

I'm doing a small area in my garden for a small patio (2mx4m).
I will be digging down to remove some earth and making a base of type 1.

In the area I have a small trench already where the soil pipe was repaired this is now back filled with pea shingle, is it ok to just put the type 1 on top of the pea shingle or shall I cap it of first with concrete before making the base with type 1?

Many Thanks

 

[PrenticeBoyofDerry]

You need a good sub-base, it will depend on the depth and the size of the aggregate, the worst thing you can do is get your sub base wrong.
This link should help you along the way.
http://www.pavingexpert.com/blocks.htm

 

[r896neo]

unless you have a trench compactor i would throw any left over pea gravel in there to bring the depth up as its uncompressible when confined within a trench. If you put mot in to the neck you will find that it will settle more than the mot around the trench because it is in a much greater depth.

Also when your doing it over fill the trench so that you have a mound 3/4 inches high on top of it and compact this in as you'll be amazed to see it dissapear into the trench.

On the converse if you put concrete too close to the surface you will have the opposite effect and the ground around it may sink relative the the concrete staying high.

In an ideal world fill it in and fill the rest of the area level too, plate it all well and leave in for a few weeks to let some heavy rain get at it and let it settle a bit. Then recheck and add more and plate again if necessary.