Replacement Blow-Away Cover, or a Greenhouse?

I got our polytunnel here http://www.feelgooduk.net/13-polytunnel-garden-greenhouse-walk-in-polytunnels the first one, 1.4m and we're very happy with it. It sits not far from our back door, but still in a very windy spot and we've had it for 5 months with no wind/rain damage. It's pretty sturdy and the zips have tags on the inside as well as the outside, so no-one can zip you in lol

we had a problem with the white straps that hold the rolled up door up. they rotted and snapped. but a quick email and a couple of pics later & they sent us replacement straps (made of the same material as the polytunnel) to sew on & a £10 refund

 

Fair enough - although the horror stories make "better copy" than the millions of successful transactions every day ... (as of just now there are 2,264,783 auctions in Home & Garden of which 73,629 are in Garden and Plants, - plenty of happy people amongst that lot, although can't guarantee every one is a bargain!)

It might be best to take a long view then. A decent quality greenhouse should see you out. Just make sure you buy a big enough one!

My thoughts are:

I think Glass is best. Easy enough to clean, doesn't "fade" over time, heavy enough that the thing doesn't become like a sail. Not well suited to kids on bikes, or yobs throwing stones (you can get toughened glass ... not sure I would pay the money to go that route though).

Polycarbonate may be better insulation in winter, the better the insulation value (e.g. double/triple wall) you choose the less light it will let through (I think). Panels blowing out is an issue I believe (usually solved by silcon-ing them in - would make disassembly difficult, but if you are buying-for-life that's not an issue). Its lighter and may be more like a sail as a consequence.

Neither is particularly good for winter-warmth. They provide protection from the wind (reducing transpiration and chilling), warm up well in sun, cool down more slowly than outside, but will still fall to the same temperature as outside (or a degree or two above). On shorter nights (in Spring) the rate of falling temperature may mean that they are 5C higher than outside at the point where outside temperature starts to rise in the morning - so that's a decent "win". But in mid Feb when we had -16C overnight my greenhouse was down to something like -12C or -14C - not a lot of help!

If you want over-winter then you need to insulate it (bubble wrap etc) and you'll need some heating. The bubble wrap cuts down the light, and thus the ability to keep on growing through the winter. (Probably not a problem, esp. if you are just wanting to over Winter things). If you want to actively grow things then artificial light, indoors, fully insulated will be better.

Consider if you will grow crops in soil or have a concrete, or similar, floor. Soil gives you more cropping height (saves the height of standing a pot on the floor and, in fact, I have lowered the soil in my greenhouse ("lowered beds" rather than "raised beds" !!)

Also, consider sloping the base slightly to the end where you would have the water butt - its easier if this is at the back as you can join both gutters to the one butt, but then you have to walk to the back to fill the can!

You might want to consider if the frame is strong enough to support the crop weight. I train all my tomato, cucumber, melon, etc. plants to strings tied to cropping wires along the roof of the greenhouse, so I don't need any other supports. Some greenhouses have "cropping bars" as an option, and some may be too flimsy to allow that?

Shelves on the far end wall may be a useful option too?

Ventilation is more of an issue in smaller greenhouses. Its difficult to control Summer heat until you get up to about 12' x 10', smaller than that and you pretty much have to throw the door open - which creates a draught and that increases transpiration.

I like having a louvre window lower down, and then roof vents, because in warm, but not scorching, weather I can create a convection current for cooling, rather than forced ventilation

Make sure you have enough roof vents, and perhaps consider automatic openers (so that they will open when you are away / on shifts / having a Sunday lie in!!)

 

presumably have to paint / oil those periodically? I prefer zero-maintenance Aluminium Mind you ... can't see mine from the house

Fold-away staging sounds good if you are planning to grow "crops" (Tomatoes etc) in the summer. Otherwise you will need somewhere to store the staging ... and I expect your garage, like mine, is generally "full"!

Sounds grand to me. I bought myself a 10' (long) x 8' (wide) when I was a teenager and it was ideal - raised veg for the family, grew cuttings, Freesias for the Winter, all that sort of stuff.

8' long x 10' wide would be much of a muchness (if that is what you are considering). Only thing to consider is if you could extend it in the future if a) you had space, b) you had funds and c) supplier had not gone bust or stopped making that model!

 

Me too, probably because it's all I've known for greenhouses since a child, and they were also all made of cedar wood. I've only taken the plunge into aluminium this year.

P.S. I've got quite a few old Halls greenhouse catalogues/price lists from the late 1950's/early 60's when you could get a Halls 10 x 8 foot cedar wood greenhouse for around £40.

 

I understand your concerns FC..Re the kids and Dog....but just an idea......
We had part of our old chicken run left over and when we got the dogs i was worried they would end up going through the glass so we hung the panel on the side of the GH....it may not be too pleasing to the eye but it does the job

 

Mesh now 50% off at Wilkos: http://www.wilkinsonplus.com/search?q=*&parentCategoryRef=139

 

FC, when I bought my greenhouse a few years back I opted to pay a bit extra for toughened glass, I have lost one panel in a Force 9/10 wind, it weighs more so will help keep the greenhouse rooted, although mine is bolted to a concrete base as the weather can be pretty nasty here during the winter months. The glass as you probably know shatters, which is less dangerous but more difficult to clear up.

 

Just to add, my six year old grandson plays ball around it and so far, so good!