Gap under greenhouse

[djhoward]

Hi all,

I have a greenhouse to put up on a (new) allotment, and wondered if you can leave a gap at the bottom, The ground is relatively uneven but firm, and I want to mount the frame on four concrete slabs in the corners. These are level, but they'll leave a 2-inch gap between the ground and frame.

Is this a viable option? Some people have told me that the ventilation will help.

Thanks
David

[djhoward]

[Tee Gee]

These are level, but they'll leave a 2-inch gap between the ground and frame.

Can't you lower the blocks another couple of inches?

If you can this should do the trick.

Leaving it open to the elements will 'yes' create ventilation, but in other situations it will cause draughts and if these get a bit icy then you could damage the crops within.

You don't mention if you are in an exposed area but if you are the wind is just going to whistle through the gap and god only knows what damage can result from this.

A gap will also makes it easier for vermin to get in.

You could spread a little loose soil around the base to cover the gap.

In other words what I am saying is get rid of the gap as I feel this will benefit you in the long term!

[johhnyco15]

firstly welcome to a4a i hope you enjoy it as much as i have teegee has makes good points you could cement the gap this will do two things stop the points tg made and also anchor the greenhouse so it doesn't move hope this helps and again welcome

[ancellsfarmer]

I think you will need to create a level base around the entire perimeter, supporting all the framework otherwise it will bow and the glass will not fit. Squareness, trueness and equal diagonals are the secret. If it bolts together, leave the bolts fingertight until all the glazing is clipped in and this will give a little "wriggleroom" to correct minor discrepancies. Also, as mentioned,anchor ie screw it down to prevent it blowing off the base. I have also found that a little extra height is beneficial if you are of a size to reach the glazing when you stand up strait. A single concrete block wall around will give a very useful extra 9" for about 66p per foot circumference

[Uncle_Filthster]

I think you will need to create a level base around the entire perimeter, supporting all the framework otherwise it will bow and the glass will not fit. Squareness, trueness and equal diagonals are the secret. If it bolts together, leave the bolts fingertight until all the glazing is clipped in and this will give a little "wriggleroom" to correct minor discrepancies. Also, as mentioned,anchor ie screw it down to prevent it blowing off the base. I have also found that a little extra height is beneficial if you are of a size to reach the glazing when you stand up strait. A single concrete block wall around will give a very useful extra 9" for about 66p per foot circumference

Can only echo this.  One pane of glass doesn't weigh much but try stacking a greenhouse side's worth of glass and picking it up. Then think what that weight multiplied by 6 (all sides and roof) will do to an unsupported thin aluminium frame

[cambourne7]

Hi

Personally i would not have the gap as the wind can get in and damage the greenhouse.

Good luck

louise

[sparrow]

As it's on an allotment, if you're thinking of using concrete I'd check your tenancy agreement. It's very much not allowed on our site and I know others are similar, though not every one.