Aluminium polytunnel base rails

[Loqueris]

Last year we bought a 45ft x 14ft polytunnel and figured we'd pay a bit extra for what we thought would be a longer lasting finish i.e aluminium base rails.

I just wondered if anyone else has had experience of using this system?

We paid just short of two grand for this tunnel and have to say wish we'd not bothered and had just opted for the wooden base rail instead. We honestly believe that the Aluminium is a serious design flaw - not the Aluminium itself but the plastic T & U pieces that are inserted to the base rail to hold the poly in place.
Those plastic piece are nigh on impossible to insert without some kind of force and the result is split poly along the length of the base plate.
Ours was in a terrible state almost immediately despite every effort to be gentle.
Looking at the design it's kind of obvious now that plastic appears to push too much against the poly and split it.

I emailed the company, sent photos and made a complaint. The company were most apologetic and did send out a replacement poly.
The thing is the plastic may not be re-useable once it's off the base rails and even if it were we'd have the same problem putting it back on.
Looks like we now have to purchase enough tannalised and design a system for attaching it another way.
What a complete waste of money.

Would like to hear if anyone else has had the same probs and if so what did you do to overcome it?

[squibbs]

My polytunnel has the same design of aluminium rails with U shaped plastic and T shaped plastic to go in afterwards. The first trial run I tore some of plastic practising until I had it sussed.

Once I pushed a reasonable amount of the polythene into the frame (I used a smoother wooden spatula handle) then inserting the U shaped plastic didn't result in tearing. I did have occasion to remove the plastic in a few spots as I hadn't tightened it enough - the polythene was stretched a little but not torn

I dont think it was all that straightforward, but I think my experience was not as bad as your experience.

Why do you need to take the polythene on and off the rails though - once its on it should stay on surely? (If I read correctly they have sent you another polythene cover)

[Loqueris]

My polytunnel has the same design of aluminium rails with U shaped plastic and T shaped plastic to go in afterwards. The first trial run I tore some of plastic practising until I had it sussed.

Once I pushed a reasonable amount of the polythene into the frame (I used a smoother wooden spatula handle) then inserting the U shaped plastic didn't result in tearing. I did have occasion to remove the plastic in a few spots as I hadn't tightened it enough - the polythene was stretched a little but not torn

I dont think it was all that straightforward, but I think my experience was not as bad as your experience.

Why do you need to take the polythene on and off the rails though - once its on it should stay on surely? (If I read correctly they have sent you another polythene cover)

We'll have to take all the plastic runners out to replace the poly, haven't a clue how they're going to fare from being taken off and re-used.

Out of curiosity how did you find the U piece went in? Was it difficult? We found it really hard to pull, get the tension and then get the U piece in.

It would make sense to get the poly in there first but without pulling it how did you manage to get a decent tension?
Plus how did you manage to get the T rail in on the top? We found it needed hammering but obviously couldn't do that because it would have created tears in the poly.

Yes, we have been given a new poly cover as the tears are really bad all the way along the base rail. I've repaired them at the moment as I don't want to waste this new poly with this system if I still can't get it to work without splits.

[Robinson Polytunnels]

The "Alitrap" system that you're writing about isn't a product that we supply but I know a lot about it from when I used to work for another company.

Different polytunnel suppliers use slightly different profiles, both for the aluminium and the PVC infills. The critical part of the design is for the infills to be the right fit in the aluminium. Not too tight to slice the polythene, not too slack to allow the polythene to slip.

In the past I am aware that some people have encountered problems with splitting the polythene while inserting the infills. The usual cause of this was inserting the Tee-Infill before the U-infill was properly pushed into the aluminium.

To be able to get full tension on the polythene with this system is not easy and is definitely a 2-man job (unless you're a professional polytunnel constructor!). I'm sure you'll have had full instructions on how to use the aluminium grip rails but I'll try and explain how I have done it.

In effect there are 3 steps to inserting the infills which need to happen about 18" apart.
The first step is to push the polythene into the aluminium groove with the U-infill. Like you mentioned, you can't pull the polythene tight and insert the U-infill at the same time so what you do is pull the polythene tight about 18" AHEAD of where you are pushing the U-infill into the aluminium. Don't try to hammer in the U-infill - that will definitely split the polythene. In the past, I've tried using something like a pizza-cutter to insert the U-infill but a strong pair of hands is usually best!

Once you've got the U-infill inserted for a length of about 18", you can start "tapping in" the Tee-infill. It's best to insert the T-infill with a rubber mallet but you must make sure that the U-infill is properly pushed into the groove.

Just continue along the rail pulling the polythehe tight 18" AHEAD of inserting the U-infill, 18" AHEAD of inserting the T-infill.

The infills should be re-usable as they are usually extruded from high-impact PVC.

Oh, and most importantly, wait for a very calm day! Good luck!

[NOOEY]

I had exactly this problem,the manufacturer of my tunnel was not as accomadating as yours,when i e mailed they replied that this was a world wide accepted method of fitting the poly and they hadnt heard of the poly splitting as you describe,I must have fitted it wrong(ie the poly between the two pvc inserts)I did not do this and fitted it as the previous answer suggested.We had strong winds forcast and I was concerned the weakened areas may cause the pvc to rip away.Luckily the pvc stayed tight,which was a relief until the next lot of high winds when the actual frame work flexed inwards and fractured at the pole junctions about 6ft up with the pressure of the wind pushing against the side of the tunnel,suprisingly the pvc remained undamaged.The pvc inserts however all pinged out on the opposite side revealing just a few slits in the pvc that was trapped in the inserts.I,m at a loss as to what to do now,the hoops are distorted and the pvc is now 'baggy' how on earth do you rebend them into the correct curve?The company are denying any responsibility,saying i'm lucky it didnt blow away(both my neighbours have tunnels which didnt sustain any damage)I feel they should replace the damaged hoops at least,the tunnel has only been erected 4 months.I would be really grateful if any one especially those in the trade has any ideas what to do now?

[SarzWix]

If the company in question have a Facebook page, suggest you post pictures of what's happened on there. They're not going to want adverse publicity, so you'll probably get a better response.

Failing that, I'd try Trading Standards.

[Robinson Polytunnels]

Hi Nooey,

Sorry to read about your damaged 'tunnel.
There certainly has been a period of sustained high winds recently and some may say that any damage isn't surprising. I would say the opposite - "proper" Polytunnels are surprisingly durable in high winds as they "flex" and move with the wind. The polytunnel framework should be flexible enough to deflect with the wind but also strong enough to withstand the bending and robust enough not to buckle.

From your description it sounds like the damage to the framework has been caused by direct pressure on the side of the polytunnel. In my experience damage of this type, whilst the cover is still intact, is rare. This would suggest that the framework is weak (or hurricane force winds!).

Most polytunnel suppliers will say they don't offer a guarantee against storm damage and claim that it's an "Act of God". Unfortunately for the customer, this argument would be likely to stand up in court. To try and pursue this on legal grounds, i.e. fitness for purpose, is unlikely to get you anywhere.

But there is some good news! Like Sarah says, any polytunnel manufacturer will not want bad publicity and will offer "something" as a gesture of goodwill to avoid this. Ask them again and if they won't play ball tell the world!

[NOOEY]

Thankyou Stuart and Sarah

Your response was very enlightening,I'm glad you feel the same way as me in that the frame work was not robust enough to support my tunnel.I,m sure of this as both my neighbours have poly tunnels and there are many in the surrounding areas all of which come through the recent winds with out any damage at all.I did some investigations and it seems the supplier of my tunnel no longer advertises them for sale,I wonder why???they are however still trading under the same name 'GARDENLIFE'but selling a sort of metal pole frame work with mesh for chicken runs and marquee's.Perhaps they can'
t replace the damaged poles because they no longer import them in from China?I see they sell the runs on Ebay so I may be able to put some sort of feedback on that.

Given he probably can't replace my poles,even if he decided to as an act of good faith,would any one know how to put the damage right,Would it be ok to leave them as they are(I have braced them with some poles off the trampoline)or would the fact the poly won't be taut mean that it will be more damaged in any more wind,we are bound to get lots more.I'm wishing i was advised to get crop bars as well,but in my ignorance thought they were for crops not to support the framework!Is it too late do you think.I'm trying to make the best of it all and get some use of it!after all it did cost me nearly 1,400.
I would be interested if any one else had any problems with a tunnel from GARDENLIFE,or EVERYDAY PLAY?the last e mail I received said they had sold a hundred and mine was the only complaint(I wonder if that was the case why did they stop selling them?)
Thanks every one!