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Produce => Under Glass => Topic started by: saddad on February 04, 2020, 08:08:23

Title: Large Greenhouses
Post by: saddad on February 04, 2020, 08:08:23
Morning all,
We have been clearing away an old wooden greenhouse, that had been neglected and was in a dangerous condition, but have been raising funds to replace it with an aluminium type. Do any of you have any experience in sourcing a large greenhouse.. our base is 12 Meters by 4.2. Or have any advice / pitfalls to avoid?

 :sunny:
Title: Re: Large Greenhouses
Post by: Obelixx on February 04, 2020, 08:49:31
That sounds like it will be very expensive, even second hand.  Have you thought about a good polytunnel?  Ours is 8m x 4m, has a good, soild framework, doors at either end and a green net for summer protection against strong sunlight.   

If you do find a second hand one, photograph it in detail and mark each piece of metal clearly before you dismantle it.   We did this with just a 3 x 2 about 20 years ago and it made rebuilding a lot easier.
Title: Re: Large Greenhouses
Post by: ACE on February 04, 2020, 10:06:58
I assume this is a community green house. I would personally replace it with a poly tunnel. Erected properly they are bomb proof and the cover lasts a really long time. Two of use erected a 15x4 in less than a day. Replacing a green house of that size is going to be a mission because of the amount of stress points if not properly levelled. It is really a job for green house erectors, that way any breakages will be covered by them. Grants are available get your begging bowl out for being sustainable, multicultural, green etc
Title: Re: Large Greenhouses
Post by: saddad on February 04, 2020, 11:49:33
We have a committee looking at it... so that should slow it down considerably, we are certainly keen on the polytunnel option. It will depend on if it becomes a Prestige/Vanity Project. I will be certainly brushing up on my "key words" ready to play Jargon Bingo in the meetings...
Title: Re: Large Greenhouses
Post by: Tee Gee on February 04, 2020, 15:10:05
This is how I laid out our communal tunnel, then after this was completed  we had the skin replaced

The beds were then offered to plot holders at a nominal rent.

As there were 10 beds in the tunnel we charged 10% of the plot rental  for a bed and rounded it up to the nearest £1

Plot rental then was around £13 so a bed worked out at £2 each p.a.

The money accrued was placed in a bank account to pay for any future maintenance.

BTW the plot that the tunnel sat on was supplied free by the Council, hence the monies going to a fund.

Title: Re: Large Greenhouses
Post by: saddad on February 05, 2020, 07:22:06
Very impressive.
Title: Re: Large Greenhouses
Post by: pumkinlover on February 05, 2020, 08:12:38
We have a large greenhouse at home from Robinsons it's been up for about 15 or more  years. Betty also sourced one for Walsall Road site.
If you decide to go down that route it's got advantages and disadvantages over polytunnels.






Title: Re: Large Greenhouses
Post by: saddad on February 05, 2020, 11:48:59
I do like the look of them... but at our size we are looking at @£12-15,000.... so it becomes a funding issue...
Title: Re: Large Greenhouses
Post by: Obelixx on February 05, 2020, 12:07:43
Our 8 x 4m polytunnel cost just under 800€, delivery included.  OH erected it on his own.
Title: Re: Large Greenhouses
Post by: saddad on February 05, 2020, 16:33:32
A poly tunnel would be much cheaper... but we have set our collective hearts on a real greenhouse... vanity, vanity....
Title: Re: Large Greenhouses
Post by: Deb P on January 15, 2021, 09:41:49
Still waiting then.......?
Title: Re: Large Greenhouses
Post by: Deb P on January 15, 2021, 09:53:05
There is a sale on at The greenhouse people where I purchased my home greenhouse a few years ago......?

https://www.greenhousepeople.co.uk/greenhouse/8388/robinsons-reigate-victorian-old-cottage-green-117-x-409/
Title: Re: Large Greenhouses
Post by: saddad on January 18, 2021, 08:05:51
Had an informal chat with some of the comm. members about it the other day, across the plots to maintain social distancing, still keen but even less chance until we can get a comm. meeting and an AGM to approve expenditure above the "cap".
Title: Re: Large Greenhouses
Post by: Deb P on January 19, 2021, 08:42:56
That’s so frustrating, especially as we’ve had a greenhouse ‘fund’ for years now! 😒
Title: Re: Large Greenhouses
Post by: Vinlander on January 19, 2021, 13:29:04
We have a large greenhouse at home from Robinsons it's been up for about 15 or more  years. Betty also sourced one for Walsall Road site.
If you decide to go down that route it's got advantages and disadvantages over polytunnels.

Visiting Shetland every greenhouse I saw was a hybrid design - they are made from twinwall polycarbonate (looked like standard 10mm) - presumably because they are tougher and warmer than either basic type. The PC must contribute a lot of strength too, so though strong connections between the sheets are essential, you might save on internal bracing.

https://www.polycrub.co.uk/ (mouthwatering pictures).

I would love to make one from scratch but for some bizarre reason PC sheet 'glazing' is banned on all our local allotments (??) I assume that they are worried about storms ripping PC sheets off a ramshackle home-made frame so they fly around like huge scythes - though people are allowed to use the same sheets on their as partitions/windbreaks/fences - in some cases merely pushed into the soil (WTF??).

The Shetlanders have much worse storms and obviously realize flying plastic is less likely and less risk than flying glass - maybe they get grants to cover the manufacturers' retail profits - maybe avoid the whole problem by simply insisting on a range of approved plans for any home builds - if the latter then I'm missing out on a clearer, tougher, warmer and much more long lasting cover purely because our useless local politicians can't be bothered and/or won't trust the site committees to regulate properly.

If you do go for a polyethene polytunnel the need for occasional re-covering is a big issue. It's definitely worth sourcing covering material with the highest possible amount of UV inhibitor - in my case the supplier revealed they have to go to a Spanish source to get it.

Of course re-glazing is even worse - though if you don't have vandals like ours the glass should outlive a wooden structure...

Cheers.

PS. A bit of background from an FT article:
https://www.ft.com/content/c9ada714-9eb3-11e7-8b50-0b9f565a23e1







Title: Re: Large Greenhouses
Post by: saddad on January 19, 2021, 16:17:55
Thank you Vinlander..
Title: Re: Large Greenhouses
Post by: pumkinlover on January 21, 2021, 07:44:37
We always put cross bracing in on a greenhouse. This prevents the lateral movement which allows the glass to slip. We've watched this happen and it creates a parallelogram shape so the panes become loose. If we hadn't gone out in a storm to watch it happen I wouldn't have believed it.
Title: Re: Large Greenhouses
Post by: Vinlander on January 24, 2021, 14:33:46
Thank you Vinlander..

Thanks,

I logged on today to make a correction to my last post - I've just discovered the polycarbonate ban on local plots doesn't exist - I think the guy I was talking to about my tunnel heard me say "glazing the vent" or "glazing one side" - whatever it was I could easily have mumbled the twinwall/PC part of the sentence(?)

Anyway, one thing this doesn't mean (of course) is that our local politicians are any better than I said - they didn't frack it up simply because on this occasion they just didn't touch it...

Cheers.

PS. I've contacted PolyCrub to suggest they design a sliding vent of the same curvature as the tunnel so it can be fitted at the apex and get that "chimney effect" that is so much more effective - it'd be much more resistant to wind than a lifting vent... Ideally put it on rollers/whatever, so it could be driven by a cheap wax-expansion opener (but sideways). I may put this variation on Top Tips when I've made a diagram.

The only reference I could find to any automatic sliding vent of this type was a vertical side vent where a light PC sheet is dropped by the opener and lifted & closed by the spring on the opener. Could be better to have it lift a panel to uncover a grille at floor level, and put the original version on the roof, but with rollers.
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