Hello all! Quick sub-pase/paving advice please :)

[AM123]

Hello everyone!

 

New to the platform and have recently purchased a property in London with a very run down garden.

 

I am looking at laying a combination of a small gravel and patio area, in total no more than 20sqm (it will be sort of U shape, with grass in the middle of the U).

My garden as it stand is an unlevel mud area, with no real vegetation except some weed, and an existing piece of concrete patio that a shed sits on.

 

My question is surrounding digging for the sub-base before laying the gravel and cement/slabs. I wondered if this was actually required or whether I could build on top of the mud etc and then raise the turf level to meet it. Is there any specific reason why digging down is better than building up?

 

Thanks in advance, all advice welcome as I am new to this stuff!

[markc]

Hi, if you have mud then you really need a geotextile to separate it from the sub base or everything sinks into the mud. If you have grass you really need to remove this vegetation layer as it will rot and shrink once separated from sunlight.

[bassanclan]

The reason for digging down ia usually because the garden is already at the correct level for the house and by adding material ontop you may bridge the dpc.

 

Also by adding material on top you have to retain it at the edges somehow. If you have a walled garden its no problem

[AM123]

Thanks to you both that is super helpful!

As it happens, the current concrete level is a fair bit above the grass level (about a 10cm step down), so I think I may try dig around 5-10cm for the area I am doing gravel/patio, and use this to build up the area I am not and try to end at the same level.

Great tip re the Geotextile too, I was planning doing a weed membrane between the hardcore and gravel/concrete, but hadn't considered under it.