Greenhouse or polytunnel

[Dynamo]

As those who saw my post in the 'What I did today's thread will know, my polytunnel went and joined the choir invisible today after a rough night in the gales.



So now my question is what to replace it with. I'd only had the polytunnel that broke for a year but in that year I realised how much I loved it and I really can't do without something similar in its place.

The first thing that came to mind was the cheap option of building something out of redundant window panels or making a wooden frame and tacking polythene to it or a mix of the two, like most allotment holders do. I really can't be bothered with all that though. I'd rather buy something straight off in one go that will last me 20 to 30 years seeing as I'm 57 now.

As you can see from the photo's, the polytunnel was about 3m x 7m so I want something about the same size. Looking online, the one that broke probably cost about £130 but there are much better ones on the market that I've seen for upwards of £500. One I saw with a steel frame looked great but only had a 4 year warranty on the polythene for UV damage. That doesn't seem very good if they don't trust their product to last very long. Maybe there are better ones on the market though.

The last option is a proper greenhouse. I know it'll probably cost a 4 figure sum but if it's going to last 20 or more years it's worth the cost in my opinion. Then there's the question of whether to get a glass or a polycarbonate greenhouse. I've heard bad stories about the polycarbonate ones but I've had one of them for about ten years with very few problems.

Anyway, any advice will be welcome on the subject. Please let me know any advice if you have any and also any recommendations.

[Greenleaves]

Both have their merits and those with the cover you had Dynamo have a short life expectancy. Either the wind rips them apart or as the cover is not UV stabilised the plastic breaks down and you end up with a netted tunnel

[veggiechicken]

If the frame is still solid, cover it with debris netting (or similar) and use it as a fruit or brassica cage. Its almost as good as a polytunnel and its selfwatering.

[Small pumpkin]

I'd never have anything but polytunnles. I have 3 and I love them. 10"x10" and 12"x20" and 14"x25".
1 first tunnels and 2 northern tunnels. The first tunnels one was brought new ( the middle size one ) and I would HIGHLY recommend them. Other 2 are northern tunnels and got both of them second hand ( just needed new covers ), equally as good when it comes to stand up the the weather. First tunnels my favourite purely because they are easier to put up.

[bario1]

Another vote for First Tunnels here, mines been up since 2013 and still looks as good as new... the polythene is meant to be replaced after 5-7 years, but I think in reality it could last a lot longer.

[bario1]

I have 3 and I love them. 10"x10" and 12"x20" and 14"x25".

They must look cute, SP! Do you have them on your windowsills?

[veggiechicken]

^^^^ That made I larf, bario.

[Paulie]

For me, greenhouses win hands down. I've seen so many polytunnels come and go on our Allotments over the years, and we seem to get more severely windy weather than we used to get (someone out there will be able to tell me if that's a real or perceived change...). Occasionally I'll get some minor weather damage to my greenhouses, but it's easy enough to replace the odd pane.

[unclefudgly]

Dynamo, whatever you do don't bin the frame just yet. Looking at the photos it looks like you suffered because the polytunnel was never fixed down properly. If done right nothing will move it and I do mean nothing.
If it was me I would try to straighten as much of frame as possible & then buy a piece of good quality polythene to cover it. My polythene had 3 yr warranty but is still strong as ever after 6yrs.
The frame does not have to be perfect, as it is the tension from polythene over it which mostly holds it in place.

so..

If necessary re-orient polytunnel to face into prevailing wind.

Buy a big enough piece of polythene to cover and bury at least 12" all round in ground.

Stake all down struts of polytunnel with at least 4' lengths of iron fence pins then just zip tie these to frame struts. This the most important thing to do by far

You should be back in action in no time

[nickdub]

I've been wondering about a poly-tunnel/greenhouse hybrid. Mine's got new plastic on it for now but it occurred to me as and when it needs replacing it would be possible to take a a slightly variant approach. You could put some batten longitudinally inside the current metal hoops, then use something harder than polythene but flexible, like corrugated plastic sheets with the corrugations running down the length of the tunnel and so combine the cheapness of polythene with a bit more longevity.

Of course making sure your metal hoops can't shift is a priority, as has already been mentioned. I built a small leveling wall first, as my site slopes, then used some old scaffolding boards as a base layer on that wall, then screwed the horizontal metal bars of the frame to them using steel banding loops.

[Dynamo]

Dynamo, whatever you do don't bin the frame just yet. Looking at the photos it looks like you suffered because the polytunnel was never fixed down properly. If done right nothing will move it and I do mean nothing.
If it was me I would try to straighten as much of frame as possible & then buy a piece of good quality polythene to cover it. My polythene had 3 yr warranty but is still strong as ever after 6yrs.
The frame does not have to be perfect, as it is the tension from polythene over it which mostly holds it in place.

so..

If necessary re-orient polytunnel to face into prevailing wind.

Buy a big enough piece of polythene to cover and bury at least 12" all round in ground.

Stake all down struts of polytunnel with at least 4' lengths of iron fence pins then just zip tie these to frame struts. This the most important thing to do by far

You should be back in action in no time

Actually the frame was really well fastened down. My problems started when some idiot who was breaking into sheds on our allotments couldn't figure out how to open the door even though it had a simple latch on it and he kicked the door frame in instead. That allowed really strong winds into the tunnel that night and weakened it from the inside as well as out. The metal struts bent and the seams were weakened. I have been repairing and repairing and repairing again ever since but this time it went too far.

It hasn't been wasted though. A mate of mine came round this morning and has taken away the metal poles. I've seen a polycarbonate greenhouse that looks ok and fairly cheap so I'm going to buy that. I also intend to make sure it's well fastened down using metposts and I'm going to wire in the panes to make sure they stay put.

[Snoop Puss]

^^ Good luck. Hope you get lots of pleasure from your new greenhouse.

[WalterWhite]

Same here! I have the 'Super Therm' covering from 'First Tunnels' with 7 year warranty currently 4 years old and looking good as new. Former cover from them lasted a decade.

Splash the cash and invest in a decent polytunnel not the inferior ones that tend to have the green gridded covers. I loose count of the number plot holders in the last 16 years who had significant issues with the cheaper polytunnels.

[Dynamo]

Same here! I have the 'Super Therm' covering from 'First Tunnels' with 7 year warranty currently 4 years old and looking good as new. Former cover from them lasted a decade.

Splash the cash and invest in a decent polytunnel not the inferior ones that tend to have the green gridded covers. I loose count of the number plot holders in the last 16 years who had significant issues with the cheaper polytunnels.

Yeah this was one of the inferior ones with green gridded covers. I couldn't complain though because I got it for nowt