question regarding Decking foudnation

Hi everyone,
I am planning to build a deck in front of the conservatory (4.5m x 5m)

I am planning to bring the deck up by using "adjustable Riser" from edecks.

My question is:

Can I kill the current grass and put crush concrete on top of it, compress it using vibrating plate and put the Risers on top of that?

I am aiming to minimize digging process but if i have to remove the grass, how much should I dig and out of curiosity why I should dig?


My last question is: Should I put the membrane suppressant beneath the crushed concrete or top of it?

Thank you

Looks an expensive way of accomplishing the job and I'd question if they're even suitable for use on a grassed area. I had a look at the risers and they look like the need fixing to a base which won't be possible with crushed concrete. It *might* be possible using 600x600mm concrete slabs but again, fixing to those will probably crack them.

Unless there's a good reason not to dig, I'd dig the holes and place in the supports that way.

If you still plan on using your method then kill the grass and skim off the grass wherever you place an upright as the grass, once dead, will rot and therefore reduce the level a touch. Don't bother with a membrane, just use a tough residual weedkiller.

Nice dog.


Silly plan.

Thank you for your quick response.

I talked to them and they confirmed they dont need to be fixed to anything. Just a firm ground.

Agree with you, no need to cover the area with Type1.

So I decided to just dig for the bases. My question now is. how much should I dig for concrete slabs? Should I first dig, then put crushed concrete, compress it , then put a bit sand and then concrete slabs? Is it the right method to make firm ground for the bases?

Thank you for the help.

** it was a silly plan at beginning I'm in the forum for a reason.

Erm, if you're digging then you won't need concrete slabs (or the weird uprighty gizmos either). There's a good guide in the wiki (I think) but basic instruction is dig hole, hardcore / something solid at base, place wooden upright in vertically and concrete in place. Do this as many times as is required for your chosen structure not to be bouncy.

There are a LOT of threads on decking - get reading! There's a tonne of very good advice on them which will help you enormously.