Decking depth issues

rick1632

I want to replace my paved patio (cheap 30mm paving slabs) with decking, but I don't want to raise the level too much for various reasons. Ideally it would be about 3" higher than current.

I had one suggestion to deck on 2x2 supports on top of the slabs, but I'm not convinced this is a great idea.

Alternate is to remove the slabs which are likely laid on sand with a mess underneath - where I have dug out it was hardcore (building rubble) with soil mixed in.

I'm thinking if I remove the slabs (30mm) and dig out 175mm, including the 3"(75mm) rise that would leave me with 280mm to play with - 100mm for the decking supports, 25mm for the deck and 150mm for the 6" joists.

That should leave me with 3 cubic metres of material to dispose of.

I could omit the supports and lay the joists directly onto the hardcore underneath I believe, but I'm guessing they'd rot far quicker that way.

Any alternatives I've missed?

Hasbeen

For the price of wooden decking and upkeep required. I would lay new paving down, perhaps country looking? Some ideas below, but plenty more suppliers etc.

https://www.tobermore.co.uk/homeowner/products/paving-flags/historic-flags-circles/

markin

I built a small step direct to concrete 4ft x 4ft  last summer just using the planks as the joists and so far it looks fine, you can get plastic feet with a nail in it that would keep it up off the slabs, Slate would work also. So yes i think using 2x2 would work fine, And composite deck would last far longer if you can afford it.

nail on feet

https://www.sinclair-rush.co.uk/categories/rubber-plastic-feet/nail-on-feet/

Paula_Smith

Why don't you want to put the decking on top of the existing slabs?