Greenhouse foundations - what to do?

[Pickup]

Hi,

My neighbour is looking to put up a 8x6 aluminum greenhouse and was asking what to use for foundations.

She wants to put a slab walkway down the middle of the greenhouse and was going to use railway sleepers for the perimeter foundation. I seem to recall reading somewhere that sleepers leach chemicals into the ground so they wouldn't be good for a greenhouse foundation.

I thought it might be better to use breeze blocks or a concrete strip but wasn't sure

a if the breeze blocks would need a footing
b what size (depth / width) concrete foundations would need to be.

Any advise appreciated.

 

[merlin50]

just put mine on concrete blocks half sunk into the ground

 

[Mrdjc]

Yes creosote flavoured veggies can't be very good for your health

depending on the soil condition, you most likely will get away with digging down to the hard-ish soil, and just laying breezeblocks with a slight gap between each block on their side up to the desired height. This way moisture can still get in and out through the "founds" as well as any worms etc. and it will be able to move around ever so slightly independently of each other.
If you tie them together and bolt the frame to it and one corner decides to go down, there's a chance it will try to rip your greenhouse in half (Depending on construction).

If you decide to go solid foundation, you need to create a proper concrete reinforced foundation which will not move at all, and if it moves that it will move uniformly.

You'd be suprised how "extreme" a greenhouse can be in terms of moisture contents, it can either be bone dry or soaking wet, you want neither of both extremes, ideally you want to have free movement of moisture in the ground.

 

[Srodders]

I have a 12'x8' and it is just set onto breeze blocks as put in the previous post. It has been up for MANY years (20+). OK, it looks slightly wonky now, but it still performs admirably.