OT: Some concrete leads

[whiskychaser]

Have bought a new greenhouse for my lady. And before you ask, yes she did want one! Of course it has to be constructed on level ground. The site is concrete and slopes away from the property and to the right with odd lumps and bumps. Digging out the concrete isnt an option. I thought of putting timber batons on the ground but I dont fancy planing 32ft of timber into 8ft 'wedges'. So I'm looking for an easy way to make an uneven, sloping surface flat without touching whats there already. Anyone help?

[Ross]

Use "sleepers" of varying thickness parallel to the building. Lay your flooring across them.
If there is the slightest potential for water I'd keep a little pitch away from the structure.

[pingu]

No need to plane the wood - as long as it's high enough you can just lay the wood on what's already there (if it's really bumpy/uneven then maybe use expandable polyurethane foam to fill the gaps). So if you site slopes 6" and you want a minimum thickness of 6" (i.e. 6" deep concrete at one end, 12 " at the other end) then you just need 12" wide plywood laid on its side.

[Phatty5BMW]

What do you plan on growing in that GREENhouse eh? :P

[whiskychaser]

I wasnt really expecting anything so constructive
I like the idea of sleepers Ross but the ground really isnt even. Its a bit of an exaggeration but it would be a bit like having a barrel on its side and trying to balance a plank on top
Pingu I like the idea. But if I use a straight piece of 6" planking wont I just end up with a 6" deep bed of concrete on a slope? The tops of the planks need to be horizontal so I can tamp it down - and end up with a horitontal surface. But the foam idea to fill the gaps is great. Not sure it would hold the concrete back though?
Phatty5BMW, you will not believe this but somebody smashed the old greenhouse. They stole 3 tomato plants and a bag of compost. My guess is they thought what you may be thinking.
Thanks for the replies!!

[Ferret]

I wasnt really expecting anything so constructive
I like the idea of sleepers Ross but the ground really isnt even. Its a bit of an exaggeration but it would be a bit like having a barrel on its side and trying to balance a plank on top
Pingu I like the idea. But if I use a straight piece of 6" planking wont I just end up with a 6" deep bed of concrete on a slope? The tops of the planks need to be horizontal so I can tamp it down - and end up with a horitontal surface. But the foam idea to fill the gaps is great. Not sure it would hold the concrete back though?
Phatty5BMW, you will not believe this but somebody smashed the old greenhouse. They stole 3 tomato plants and a bag of compost. My guess is they thought what you may be thinking.
Thanks for the replies!!

Whynot get some plyboard up to the edges of the 'crete, create a perfect vertical and fill with some fresh concrete to level it off?

Sorta |/\| and fill in the gaps?

[whiskychaser]

Whynot get some plyboard up to the edges of the 'crete, create a perfect vertical and fill with some fresh concrete to level it off?

Sorta |/\| and fill in the gaps?

I dont have a concrete base as such at the moment-just a very wonky surface. The pro's would probably dig an 8ft square hole and start afresh but thats not an option for me

[AngryPopTart]

Can't you just place planks on all four sides, like a mold or form, and seal them at the bottom so there's no leaks, then fill the inside with fresh concrete until it's flat all the way across?

[whiskychaser]

Can't you just place planks on all four sides, like a mold or form, and seal them at the bottom so there's no leaks, then fill the inside with fresh concrete until it's flat all the way across?

That would be the idea. The big problem is how you seal the bottom to stop the new concrete running out

[AngryPopTart]

Then just build a form around the concrete, even if it's larger than the existing slab, with the boards in the ground and pour a completely new slab to cover over the old one.