Raised Patio

[Roger]

Hi All I want to raise our patio so it reaches up to the patio doors we had fitted. We don't want to use decking.

As far as I can work it out, I'll build a retaining wall around the intended patio area, fill it with rubble and crushed hardcore then lay slabs on top.

It will need to be four or five feet high.

Can anyone recommend the depth of foundations, thickness of the wall (dense blocks) etc and can I use any of the soil removed for the foundations to fill inside the raised walls.

Do I need to talk to Building Control or Planning.

Thanks Roger

[Set Square]

It would be cheaper just to issue everyone with parachutes!

[Ian Stirling]

Decking? You could even have a storage area under it.

[Toby]

Hmm it would need a lot of infill, so merging the above ideas, how about building the wall as normal but top it with a beam and block floor finished with flags. Retains storage underneath, and does not compromise the existing DPC on the house wall.

[Ian Stirling]

Then again, there is always the other way. Dig under the foundations shoring as you go, and support the foundations on steel girders of adequate section. Now, simply remove earth underneath, and lower house 4-5 feet. You won't even have to relay the patio.

[Ian Stirling]

Somehow I completely missed the "We don't want to use decking" bit of that post. Oh well. You can of course put slabs on top of decking.

[Terry]

Roger: Wow! If patio is 10 by 10 feet, say, that's around 500 cubic feet of soil, fill, rubble, what have you. Not only a lot of work (Hire machinery? Access to that area for a dump lorry etc?) And will require proper compacting to avoid settling. Handling slabs five feet above ground! And unless the ground slopes usefully a massiive 'pile of dirt' which can asorb water right alongside the house structure? Make sure it is drained in same way that embankments are? Personally I'd not tackle it that way but you know the property. Terry. PS. If not machinery accessible; wheeling barrow loads up an incline! Whew! Even 'building' an inclined ramp 'up' five feet is quite a job (and space)? Or 1000 to 2000 one half to one quarter cubic foot bucket loads of 'fill' lifted five feet and dumped (by two people?). But can be done as a fitness project!

[Pete C]

Hi,

Might be possible with RSJs, in any case finding a structural engineer who is experienced in this. and paying for an hour of their time would be well worth it.

cheers, Pete.