Allotment Gardening Advice Help Chat

Chatting => Design and Construction => Topic started by: chumpchange on December 16, 2007, 12:24

Title: polythene greenhouse?
Post by: chumpchange on December 16, 2007, 12:24
i am looking at building a polythene sheet lined greenhouse, basically a structure covered in polythene sheeting inside and out for extra insulation, has anyone else tried this? does it work? i wanna grow chillis and tomatoes in it, and maybe aubs too but who knows for sure!

thaaaanks
Title: polythene greenhouse?
Post by: WG. on December 16, 2007, 13:42
Hi and welcome.

You have two main problems to address: (1) ventilation and (2) prevention of hot-spots and tearing where polythene contacts the frame.

If you have an unglazed greenhouse frame, then I'd suggest glazing it.  If you are starting from scratch a commercial polytunnel or simple loops of alkathene pipe as a frame with a single skin of horticultural polythene.

Extra insulation can be provided internally for early spring should you choose to heat it.
Title: polythene greenhouse?
Post by: chumpchange on December 16, 2007, 18:44
thangyow

i was thinking of using a big wooden frame for it, and having it totally covered in polythene sheeting so that no wood was exposed.

what would i need for ventilation? would an inch or two slit either side under the roof be sufficient?

with regards to the polythene, i didnt realize there was different types. is one better than the other?
Title: polythene greenhouse?
Post by: WG. on December 16, 2007, 20:36
Where are you based please?
Title: polythene greenhouse?
Post by: DD. on December 16, 2007, 22:27
Quote from: "chumpchange"


with regards to the polythene, i didnt realize there was different types. is one better than the other?


You would need UVI (Ultra Violet Inhibited) polythene, otherwise it would go brittle in less than a year, such as the stuff here...

http://www.allplas.co.uk/acatalog/Ultra_Violet_Inhibited_Polythene_Sheeting.html

Welcome from me also, why not drop in on the 'Welcome To The Forums' forum & tell us a bit about yourself?
Title: polythene greenhouse?
Post by: burlington on December 16, 2007, 22:28
You should use UV polythene only.

Also, if you put slits in the skin, then unless these are closed at each end of the slit with tape then this would create a weakness in the structure and, one day, along comes the wind and away goes your cover! :cry:
Title: polythene greenhouse?
Post by: chumpchange on December 17, 2007, 10:17
awesome advice, thanks ! i will defo get the uv polythene, don't want my shack to look like stupid.

hopefully im getting some timber today, so i can show you all pix!


i'm in herts btw :- )
Title: polythene greenhouse?
Post by: noshed on December 17, 2007, 11:04
Rigid plastic might be better - see the album for pics of my greenhouse. Not pretty but it works
Title: First Greenhouse
Post by: The Singing Gardener on January 12, 2008, 17:24
My first greenhouse was a polythene sheet lined greenhouse. Get some help when you erect it - it would make it easier. I didn't!

I found that it was a great way of getting into greenhouse gardening. I used to open the door in the morning to let air in as the sliding window I found was only good for opening when I was in there as you either had it fully open or closed. There was no way of having it half open.

Make sure that it's attached to the frame. I had no problems with the wind. I enjoyed my time in the greenhouse as did my cat who went in there every afternoon until evening to sleep in the compost bin.

I'm now looking to buy a new glass greenhouse and can't wait to get it.
Title: Poly greenhouse
Post by: Chillitoes on January 20, 2008, 23:02
Hi, chumpchange I have both glass and solid poly sheets in my greenhouse currently. I've also had, in the past, plastic sheeting over part of it. It's a painted steel structure. In my experience I would choose glass every time. Solid poly sheets only as a stop-gap. Plastic sheeting only in an emergency, even though my greenhouse is sheltered from strong winds.
 I know it seems easier to stretch a single sheet of plastic over the lot, but all you need is a little tear and some wind rrrrrriiiip! it gets messy real quick. Glass is a pain sometimes granted, but it's the best at the moment IMHO


Funny enough, I've just been reading a page linked to by Aunt Sally about an idea for a poly-tunnel greenhouse. Mostly plastic construction, no sharp edges etc.  but the plastic sheeting remains the weak link!
 It's Here  (http://www.powen.freeserve.co.uk/Projects/polytunnel/polytunnel.htm) it might be of some help to you - Good luck with it anyway