Concrete base for Greenhouse

cubegame

I did post a thread a few days ago about this but have now since exposed the site we want to use and it looks more difficult.

Basically I want to install a concrete base for a Greenhouse where our shed was. The site looks like this:-



I had thought the shed was on a hardstanding but it appears to just have a perimeter base made from concrete blocks cemented down.

The greenhouse base is roughly going to follow the lines laid out by the various planks in the photo. Thus there is a mixture of existing hardstanding and soil. The site also has a downhill slope from right to left in the photo and is probably some 10 to 15 cm lower on the left.

What would the best option be? To fill soil areas with hardcore and then raise the whole area with concrete? Or would it be better to bite the bullet and get the whole lot out and lay a concrete pad from scratch?

Gloomendoom

I'd probably do the latter because I'd be worried about the path dropping.

Love the blue shed BTW

cubegame

Gloomendoom wrote: »

I'd probably do the latter because I'd be worried about the path dropping.

Love the blue shed BTW

My feeling too. Especially when on 2nd inspection the concrete appears to be just 3 inch thick slab which I can get a bar underneath. Sledge hammer time.

Nice blue isn't it. The shed we moved from this space was blue as well!

:-)

Bonbon

Apologies....I've just added to this post to save starting a new thread. Can anyone help me calculate how much concrete I need for a shed base 3m x 2m. It's dug out to 6" deep and half filled with hardcore. I have searched the internet and just about everyone/company is telling me different.
What are the options? I know you can mix it yourself or buy cement plus 'all in' ballast, or get bags of readymix concrete and just add water.
I have seen ratio of cement/sand/gravel at 1:3:6
and another site calculated that I need 7x25kgs cement + 1.05 tonnes ballast
I'm totally confused. Me and b/f want to do it over the bank holiday and have booked the cement mixer so now just need to know what to mix.
I'd be grateful for any help thanks.

tony6403

3m x 2m x 0.075m = volume . This gives 0.45 cubic metres of concrete. 1:3:6 seems too lean ( i.e. 9 to 1 overall )
I would estimate 7 x 25kg bags of concrete , 0.25 cu m sand and 0.35 cu m aggregate.
That's a lot of mixing to do even with a machine - I would order this quantity from a ready mix company .
Have you prepared your shuttering?

Bonbon

Tony6403, thanks for your reply. I started another thread about this and received more advice.I'm pleased to say job done without any hiccups.It's not the most amazing finish but its pretty good for a first time, and after all, it's going to have a shed covering most of it.