Thinking of doing some major landscaping in the garden and could end up with a big pit. Was thinking about the possibility of making it into a basement with a shed on top of it. Was thinking about block walls but what would I need to do to make it water tight? And how best to support a shed built on top of it? More hassle than it’s worth?

Edit: and would I need planning permission for this sort of thing?

For waterproofing google ‘tanking’. If it isn’t too big you shoiuld eb able to do the whole thing with a single sheet of DPM which should be pretty waterproof. The shed on top won’t be heavy so some block walls and decent sized joists should be fine.

Not sure about planning but the limits for out buildings under permitted development are fairly well defined. The limit of 2.5m from the top of the roof to the original ground is usually the tricky one. Might be an issue depending on your landscaping. There might also be an issue with party walls if it is close to boundary.

shipping container, sunk into the ground, with a hole cut into the top? 🙂

You should get a pre-emptive response in to all of the comments about basements, why exactly do you want it!

perfectly doo able, dig hole, line with waterproof membrane as you are doing the block walls, leave the bottom lined with gravel on the outside of the walls to act as soak away , jobs a goer.

as for planning- not sure on your area, but it would be withing permitted development rights where we are.

take plenty of piccys for us !

Disappointing. 4 responses, and not a single Frizl reference.

Warton do you do a lot of “interesting gardening” 😉

I had an underground shed built at my last house. The garden had a big level change so we built the shed and had a lawn on top of it. Construction was tanked blockwork with a concrete block and beam roof. The damn thing leaked so we ended up cutting a small drainage channel in the floor at the base of all the walls that exited into a sump in the lower garden. The walls always stayed slightly damp but the floor stopped flooding. Not brilliant but OK as a bike store. Wooden items (including the doors) did start to mould over time. The problem was that once it had been built and back filled/covered the tanking couldn’t be repaired.

Well I have a garden that slopes away from the house. Probably a good 7ft down to the bottom. Was thinking about levelling the garden with some big retaining walls on the boundary. A colleague actually suggested a dungeon 🙂 and this made me think of a shed with a basement. Would be used for storage, maybe bikes, so would need to be dry.

Edit: wonder if you could line it with a membrane inside the block work? Then maybe put a layer of insulation over that? Would worry about building it and then having it leak.

I’ve often dreamed of a garden shed with a secret trapdoor covering a pit, into which you simply lower your bikes.

Many, many years ago my brother & I dug an inspection pit in the garage whilst my Mum was on holiday. 🙂

takisawa2 – Member

I’ve often dreamed of a garden shed with a secret trapdoor covering a pit, into which you simply lower your bikes.
How could you do that to them!

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