Polytunnel polyethene - the right weather?

[MadamJoJo]

I'm in the process of constucting my polytunnel - hoorrahh, but I'm slightly concerned about the temperature at the moment. i.e. Will the polyethene stretch & become slack when the weather gets warmer ? I'm using the trench method, so tightening it off later is not really an option. I could wait until it gets warmer, but I'm keen to get sowing. Has anyone had problems constructing their tunnel this time of year? Any advice would be muchly appreciated. MJJ

[brooklynodog]

Good luck with your enquiry. I am in the same dilemna, all the metal and wood work in place, greenhouse and cold frame full of goodies, now just waiting for the wind to ease to a dead stop! I did ask my supplier the same question (1st tunnels) and they said they erect p/ts all year round, though the warmer the better as the film has to be drum tight! They didnt comment on slackening though. P

[Paul Wagland]

Two things to watch out for - the first being the wind. You really don't want to spend most of your gardening budget on a new cover to see it snagged and torn in an unexpected gust. Get lots of help if you are working on anything other than a dead-calm day.

Second, temperature. As you have pointes out the plastic will stretch more in warm weather, and if you install it on a cold day it may start to sag when the sun comes out. My advice would be to store the plastic indoors in the warm so it's nice and supple. Then wait as long as you can bear for a sunny day, and get the plastic in place without too much messing around so it doesn't have a chance to cool down.

Good luck!

[MadamJoJo]

Luckily it it quite calm here at the mo. All the metal & wood work in place this end too. I did attempt to drag the polythene indoors, but it is so darn heavy!! My new idea is to rest the polythene over the frame, then getting a space heater to heat the semi-covered tunnel from inside to help. Otherwise, pray for a heatwave over the weekend!!

[brooklynodog]

"On a hot day you may find that the polythene is bagging between each hoop. However when it cools down later that night the polythene should go back to its original form."

Just had this email response from my supplier re slackening. Followed by this one:-

"I would personally fit the polythene at your earliest convenience. You don’t get much more stretch out of the polythene on a warmer day and as I have already mentioned our construction team build polytunnel all year round and achieve a skin tight polythene cover"

So thats as clear as mud then.

[MadamJoJo]

Mmmm...oh well, let's hope your supplier's helpline is not south of the equator!! will give it a bash anyway- let me know brooklynodog how you get on!!

[brooklynodog]

"Otherwise, pray for a heatwave over the weekend!!"

I see you are in the west country as I am, and I think we have strong winds forecast from Friday onwards. Met Office: Taunton: forecast

[MadamJoJo]

Just my luck - I'll have to put the troops on hold !!

[MadamJoJo]

P.S. Thanks for the heads up !

[brooklynodog]

Got my film on today Madam Jojo, how you getting on? Just got to tidy it up and put doors on tommorrow, then I can start planting!!

[sewer rat]

Woke up this morning to flat calm and reasonably sunny morning so made a couple of phone calls and eventually got a mate to agree to come out and assist me recover my tunnel., So - I got my polytunnel's new cover on today - started at 10am and finished hanging the doors again at 18:30. Not bad for only two of us and a puppy that was determined to interrupt us as much as possible.
Tomorrow is putting the staging back in, along with the capillary matting and then clearing all the pots, trays and hanging baskets from my store back into the tunnel so I can reclaim my shed for my veg sales and boxes. Compost due to be delivered on Monday so full steam ahead from next week.

[MadamJoJo]

Well done brooklynodog & sewer rat for getting your covers on .....me, I got slightly dispondent yesturday & decided to mow the lawn while it was fine instead. Perhaps I was getting over enthusiastic thinking about putting the cover on at the w.end, as I still have lots of rotovating to do in the polytunnel space (now digging as the roty has died..not bad for £20 I suppose!!). I think I'll wait for the weather to clear....pop down the pub for some motivation and/or inspiration, then go from there !! Have fun planting & think of me !!