Polytunnel

Still finding my way round this forum; have raised this issue in a thread somewhere but maybe I had better send it as a new post. A friend who shares the allotment with me has suggested getting a polytunnel & on researching Amazon I note that the size we want starts at something like £150 BUT the reader feed back for the model I viewed was not good in that both the comments said the product was poor value for money in that the plastic sheeting shredded during the first windy day. Can anyone -from experience - vouch for a model that is both reasonble in price yet durable please? Thank you.

 

@Acorn Which particular model on Amazon were you looking at? (you wont be able to post links yet, but the size, seller and price will enable somebody to locate it) If it was about £150 I'd guess it was probably one of these 6 x 3m tunnels.


If well anchored down and with some additional timber supports it shouldn't shake to bits in a gale. The cover will need replacing after a few years - a replacement will cost about £80, or about the same for re-covering in normal polytunnel polythene (but it wont have vents). Use anti-hotspot tape on the frame.

The door zips will fail, so allow for adding a timber frame and hinged door(s) at the zip end. Alternatively, when erecting install 2 vertical timbers behind the zips and fix a battens from the outside to permanently seal it off and form a new, narrower hinged door at the front. If the door posts are fixed to the tunnel tubing it will help brace it.

Looking at Amazon reviews, the only ones that concern me are those about some brands of polytunnel skirts being too narrow (only 2"). I think that on Feelgood (AKA Grow-ur-own) tunnels they're 7" wide (I have one).

 

Thank you Scrungee for the advice, I have just looked at the options on Amazon & can't locate the precise one for £150. that I saw last week. However, I note that there are numerous in that price range so plenty to choose from. What -if any- is the difference / benefits between the green and clear plastic coverings? [The ideal size we would like is 7 Mtr X 4Mtr.] If you can recommend a good quality model I would appreciate knowing the supplier. Of the members with polytunnels, -out of interest- who has had the model the plastic covering of which has lasted the longest? Shalom Dave.

 

I think:

Loose fitting covers
Roll-down "windows" in the side
Flimsy slot-together frames
Lack of ground anchors
Zips for doors

are all negative points, and likely to contribute to short-life of the cover and/or the tunnel living up to the nickname of being a "blowaway".

Its a compromise with Cost of course, but "buy cheap, pay twice" does apply.

It would be worth looking for a second hand one on eBay. You'd need new plastic sheeting, but the "hoops" etc might come cheap and/or be of far superior strength to what you might be able to buy new.

I don't suppose Glass is allowed on your allotment, but I bought a glass aluminium greenhouse 30' x 10' (so similar to your 7M x 4M size) for £400 ... thus I expect that you should be able to find a decent quality second hand tunnel for £100 or less.

 

Thank you Kristen, yes glass is in fact allowed as is evident by the greenhouse substitute I constructed from the sections of a second hand conservatory (see above). I will certainly remember the weak points you mention like "Roll - down windows" in the sides and chances are if we do acquire one I would construct a wooded door frame and maybe a wood door so the zip features would be eliminated. You mention Loose fitting covers! It should have crossed my mind -but did not- that the plastic covering must come in sections as one single cover for a 7 x 4 Mtr e.g would be unfeasible and most likely impossible to handle. Last week I visited another allotment combine and talked with a guy who had a poly-tunnel supported by hoops of yellow plastic piping that had come from some industrial source. Just the job if one has the contacts I guess. Cheers again Dave.

 

If you can rip-off the materials from work its probably a good route:

http://www.overthegardengate.net/userpages/pp_view.asp?FName=polytunnel

 

I looked at that link Kristen and not that the plastic cover is £80, in the event that the scaffold poles and yellow gas pipe can be scerounged for nothing or for a song that route sounds interesting as the construction side is elementary. However, if such items are not readily to hand the price (about £120 -£150) for a new tunnel is not too outrageous seeing the pack comes complete with the framework. Seeing the allotment is fully planted for this season I suspect we will wait till the winter has come and gone before we launch out and acquire one. Regards Dave.

 

I think even if you had to pay full price for the components (and assuming they aren't hugely expensive) I think the fact that it is stretched plastic, tight over the hoops, means that it will last longer than the lose covers - so might work out cheaper in the long run ... but once you get to that point it might be better to buy a posher tunnel (ground anchors and all that jazz ... such as www.firsttunnels.co.uk - their "basic" price for 7M x 4M-ish is £534 including ground anchors)

 

A couple of options suggested above

1) DIY

OK if you've got a source of sufficient free scaffold tube/boards, polythene pipe, etc. plus you're prepared to wait until you've managed to source them all, otherwise it will cost a lot of money to build:

In my experience, the days of being able to wander around construction sites and pull stuff out of skips has long gone. Visitors need to wear safety footwear, hi vis and hard hat, attend a site safety induction course and report to reception to be signed in and out of the site.

You can buy a 'proper' polytunnel for the sort of money it would cost if you had to buy all the stuff for a DIY job http://www.firsttunnels.co.uk/polytunnel.asp?cbowidth=10 and select the 10 x 20 foot option


2) Second hand from ebay

Saw this frame there Polytunnel frame only. 10'W x 25'L x 6'6"H located BA4 4QN near Shepton Mallet which went for £62, but the tube's only 25mm dia., there's only 5 hoops on a 25 foot long tunnel, the ends are set in concrete (so a Kango hammer's probably required plus there's the risk of damage to the tubing), bolts might need replacing, etc. What the doors would be like to remove is anybody's guess.

Buying a 10 x 20 foot 7 hoop 25mm dia. frame only from ebay would have cost £112.20 delivered http://www.ebay.co.uk/itm/310959687279?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT After adding 5 hours travelling time + a day's work +£35 fuel costs I don't think it's worth the hassle, all to save just £15.20.

But for only £7.20 more you could get it complete with a cover from Amazon http://www.amazon.co.uk/dp/B007ITTT...TF8&colid=1CVRB2TYJJZQW&coliid=I312CMWYJIP2ET Those green mesh covers sell for £80 so sell it on ebay and put the proceeds toward a proper polythene cover.

I've been looking on ebay for years but nothing has come up at a sensible price + reasonable distance.

 

Very useful and fascinating analysis @Scrungee, thanks.

The FirstTunnels works out at about exactly your calculated cost for materials alone - and "made for the job". Personally I abhor "I blagged all the materials from work" unless they were genuinely going to be Skipped - just possession of a 50M roll of MDPE would be "blagged" in my book ... not hard to reuse / resell that.

I haven't looked at second hand Polytunnels on eBay, but I do look at glasshouses from time to time. The small ones go for a reasonable sum (although cheap compared to new), but anything 12x10 and bigger is usually a bargain. It was a while ago now, and maybe there is more demand / savvy but my 12x10 was around £200 from memory, and my 30x10 £400, and they are old, over-engineered & robust aluminium frames which had all, bar a pane or two, of their glass intact. An experience/fun days outing disassembling too, although if I had to pay someone to do it the sums probably wouldn't add up.

 

Premier Tunnels have reduced their prices [1] and their 10 x 20 foot tunnel has been reduced from £433 to £389.70, making it cheaper than a DIY tunnel made from bought materials http://www.premierpolytunnels.co.uk/product-details.asp?prod_id=12&level_id=9&level=2

[1] 10% Off until 1st July 2014. 15% off 'dream polytunnels' http://www.premierpolytunnels.co.uk/prod_list.asp?level_id=63&level=2&pgno=1