Installing patio over tarmac?

[goldeagle]

I want to install a raised patio to replace the existing tarmac surface in my garden. This is probably going to be a DIY project as I can't even get anyone to come round and quote.

The existing tarmac surface is not level, so I plan to install the patio so that it lines up with the highest point of the existing tarmac.

I know I will have to put a short retaining wall in around the perimeter which is fine. However, I wasn't sure if I should be digging up all the old tarmac first or can I just compact Type 1 directly on top of the existing tarmac before?

There are a few areas at the high points which will need tarmac removing so that I can get the right levels, but would appreciate any views on whether I should be removing all tarmac before laying the sub-base.

Some photo's below...intention is to build the patio up to the bottom step. The highest point of the existing tarmac is in the corner with the downpipe, this is pretty much level with the finished height of the planned patio.

 

[Nige F]

Have a look at pavingexpert.com cuz I'm not sure on this one

 

[Tigercubrider]

How much increase in level will there be?

 

[goldeagle]

Increase in level will be between 100mm and 400mm depending on the slop

 

[Tigercubrider]

I think you may need PP?

 

[goldeagle]

Not sure how that relates to whether or not I should take the tarmac up before laying a patio...

Ground level is taken from the highest point, and patio is only 100mm higher at this point. So no planning permission

 

[freddiemercurystwin]

If it were me I'd consider paving pedestals, though not cheap they would enable you to be able to adjust them over the years should the tarmac drop, which it can do.

 

[Captain Nemesis]

Looks like a drive-by-traveller special.

Dig it all up and do the sub base properly.