Up, Up and hopefully not away.... My Polytunnel

Forum rules
This area is for Reference and discussion of plant hardiness, overwintering methods and tips, and planr protection.
User avatar
Dave Brown
Site Admin
Posts: 19686
Joined: Sun Jul 09, 2006 10:17 am
Location: Chalk, (Thames Estuary) Kent, England 51.5N 0.3E
Contact:

Up, Up and hopefully not away.... My Polytunnel

Post by Dave Brown » Tue Oct 20, 2009 11:42 pm

Chapter 1 - Preparation, Base and Erection. :wink:

This project started in January 2008, but that was the year of the wet weekend, and ground work was just not possible most of the time. The idea was to erect a polytunnel at the top of the garden, which had been an under used area for most of the last 25 years.

Work started in ernest in March 2009 with the cutting back of the Elderberry shrubs and digging out much of the overgrown hedge. Work had to stop in late April as other beds needed work before summer planting could be started. Then the Arid bed was created finally finishing in July. Then there were 200 bags of clay dug out and taken to the dump, to level the area, followed by a general garden tidy before the Mega Party in August. Work finally started again the last week in August.
190809 Polytunnel 01.jpg
Plants were dug out from where the poly is going, potted up, and will be planted in the bed next spring.
130909 Polytunnel 02.jpg
Plants removed and ground levelled
130909 Polytunnel 03.jpg
The base was secured by 12 x 75 x 75 posts sunk 30cm into the ground with 10cm protruding. This will raise the polytunnel giving an internal height of 2.3m (7'6"). These were cemented into place using postcrete, a very quick drying post mortar. You fill the hole 1/3 full of water, pour on the postcrete until all the water is absorbed, then you have about 2 minutes to position the post vertically before the post crete starts to set. Here is the base in place with the sideboards in place.
041009 Polytunnel 04.jpg
Next the top ledge was added as the platform the legs would sit on and that the cover wouls be battened to... but disaster struck and we had the first heavy rain for many weeks soaking the ground. The dust like clay turned into a brown equivelent of blu-tac with about 1cm sticking to shoes with every footstep. Work was almost impossible as the shoes became very heavy after a couple of steps. Then I had a brain wave. I had to trim the Trachies lower leaves anyway, so I'd use them as a ground sheet to avoid walking on the clay icon_thumright
101009 Polytunnel 06.jpg
Frame parially erected. At this point I was worried about it's strength and would have happily paid £10 or £15 for a more substantial diameter pole :roll: However having said that I have paid £10 more for the DIY base, than I paid for the Polytunnel :shock:
101009 Polytunnel 07.jpg
Next I had to add the cover before raising the poly to it's full height as I could not reach easily. As the cover is fitted, shape wise, it is not the easiest thing to get into final position on your own. This took about 20 minutes of tweaking to get right.
101009 Polytunnel 08.jpg
I was running out of daylight so had to work fast to get the sides battened down. Although the night was due to be calm. I finally got the sides battened finishing in the dark :roll: The next day I battened the ends but these were a bit more difficult due to door positioning.
111009 Polytunnel 09.jpg
View from inside
111009 Polytunnel 10.jpg
Chapter 2 insulation to follow
Best regards
Dave
icon_thumright
_________________________________________________
Roll on summer.....
http://www.hardytropicals.co.uk


User avatar
Eddy
Posts: 373
Joined: Mon Sep 17, 2007 8:03 pm
Location: Stevenage, Herts

Re: Up, Up and hopefully not away.... My Polytunnel

Post by Eddy » Wed Oct 21, 2009 10:56 am

Well done Dave it looks good, especially as you did it all on your own. :) icon_cheers
PS. What's going on the floor? Decking? icon_scratch :D


User avatar
themes
Posts: 2933
Joined: Mon Jun 23, 2008 12:22 am
Location: Birmingham

Re: Up, Up and hopefully not away.... My Polytunnel

Post by themes » Wed Oct 21, 2009 1:21 pm

icon_thumright looks worth all that effort. Its a clever idea recycling all those palm leaves very ingenious.
Regards,

Mo

start mo-derating


User avatar
Dave Brown
Site Admin
Posts: 19686
Joined: Sun Jul 09, 2006 10:17 am
Location: Chalk, (Thames Estuary) Kent, England 51.5N 0.3E
Contact:

Re: Up, Up and hopefully not away.... My Polytunnel

Post by Dave Brown » Wed Oct 21, 2009 1:22 pm

Thanks Eddy :D

Unfortunately the Poly was a bit intrusive in that part of the garden where only shrubs and trees had been before. so I built a screen to help mask it.
121009 Polytunnel 12.jpg
Screen under construction
121009 Polytunnel 11.jpg
Screen complete
201090 Polytunnel 13.jpg
The soil was dug out around the edges and polystyrene added to a depth of 20cm to insulate the sides and soil.
171009 Polytunnel 14.jpg
Next came the bubblewrap. This has been tucked under the frame which is not the best method, but is the only way I can see of keeping it up. I started at the top and worked down the sides, this ensures that the overlaps stop rising heat going under the insulation. The door insulation was is a continuous piece of the ridge insulation to stop it pulling off when pushed out of the way when using the doors.
171009 Polytunnel 15.jpg
I have laid a border membrane to stop weeds and to reduce humidity and condensation over the winter. The membrane acts as a mulch allowing water to drain through but stopping moisture from seeping back up from the damp ground into the poly.
181009 Polytunnel 16.jpg
The lower 60cm of the sides are covered with 25mm polystyrene to help stop heat loss and reflect light
181009 Polytunnel 17.jpg
and finally 50mm of shingle as flooring
191009 Polytunnel 18.jpg
My polytunnel :wink:
201090 Polytunnel 19.jpg
Best regards
Dave
icon_thumright
_________________________________________________
Roll on summer.....
http://www.hardytropicals.co.uk


ElTel
Posts: 334
Joined: Tue Jul 14, 2009 4:52 pm
Location: Nrothampton

Re: Up, Up and hopefully not away.... My Polytunnel

Post by ElTel » Wed Oct 21, 2009 1:30 pm

looks really good, very professional job and great idea to publish it as a how-to guide. how long do these type of pollytunels last for, presumably with a strong base its quite a long time
the brainy triplet


User avatar
Dave Brown
Site Admin
Posts: 19686
Joined: Sun Jul 09, 2006 10:17 am
Location: Chalk, (Thames Estuary) Kent, England 51.5N 0.3E
Contact:

Re: Up, Up and hopefully not away.... My Polytunnel

Post by Dave Brown » Wed Oct 21, 2009 1:41 pm

I'm basing mine on a 3 year life, but this was about 1/5th of the cost of a proper polytunnel, hopefully the base will last a lot longer.

Ebay Item: 150382038406
Best regards
Dave
icon_thumright
_________________________________________________
Roll on summer.....
http://www.hardytropicals.co.uk


Dave in Warrington
Posts: 1578
Joined: Tue May 13, 2008 7:59 pm
Location: Warrington, Cheshire

Re: Up, Up and hopefully not away.... My Polytunnel

Post by Dave in Warrington » Wed Oct 21, 2009 7:14 pm

Great work Dave and it won't be long before it's full :roll:
Dave


User avatar
SteveW
Posts: 1747
Joined: Mon Jun 18, 2007 7:11 pm
Location: Hoo peninsular,Kent

Re: Up, Up and hopefully not away.... My Polytunnel

Post by SteveW » Wed Oct 21, 2009 7:20 pm

Looking good Dave,don't suppose you fancy popping round and insulating mine do you? :lol:
Have you had any problems with your cats climbing up it yet?


User avatar
bobbyd44
Posts: 1243
Joined: Sat Jan 31, 2009 4:54 am
Location: northwest

Re: Up, Up and hopefully not away.... My Polytunnel

Post by bobbyd44 » Wed Oct 21, 2009 7:24 pm

great pics dave really helps to see whats gon into what you have done i am sure it will be much eisier for others now!! if only i had the room icon_scratch
nice one, cheers,ta!!
rob


User avatar
redsquirrel
Posts: 12169
Joined: Thu Feb 26, 2009 8:35 pm
Location: bristol
Contact:

Re: Up, Up and hopefully not away.... My Polytunnel

Post by redsquirrel » Wed Oct 21, 2009 7:37 pm

my first one lasted a year then disintegrated.dont think they are as uv treated as they say. got some heavy duty repair tape for the new one and a spare cover incase of any disasters over winter.the bubblewrap is going up in ours this weekend.thanks for showing how you did it dave,i was wondering how to get it to stay up in the right shape icon_thumleft
mars ROVER broken down. headgasket faillure


User avatar
mushtaq86
Posts: 722
Joined: Mon Aug 25, 2008 8:28 pm
Location: hartlepool

Re: Up, Up and hopefully not away.... My Polytunnel

Post by mushtaq86 » Wed Oct 21, 2009 8:15 pm

Looks great Dave. icon_thumright icon_thumright icon_thumright


User avatar
Dave Brown
Site Admin
Posts: 19686
Joined: Sun Jul 09, 2006 10:17 am
Location: Chalk, (Thames Estuary) Kent, England 51.5N 0.3E
Contact:

Re: Up, Up and hopefully not away.... My Polytunnel

Post by Dave Brown » Wed Oct 21, 2009 8:17 pm

I hope it lasts more than a year Darren :ahhh!:

I hadn't thought of it being a course on bubblewrapping, but the problem you may have is the tension of the poly. When I had a proper polytunnel many years ago I could not get the bubblewrap between the frame and the poly as it was too tight :roll:
Best regards
Dave
icon_thumright
_________________________________________________
Roll on summer.....
http://www.hardytropicals.co.uk


derrick
Posts: 1905
Joined: Mon Oct 13, 2008 12:15 am
Location: Southanpton

Re: Up, Up and hopefully not away.... My Polytunnel

Post by derrick » Wed Oct 21, 2009 8:58 pm

Looks realy good Dave how big is it strong base on it . I just havent got the room .


Conifers
Posts: 13147
Joined: Sat Jun 20, 2009 2:11 pm
Location: Northumbs

Re: Up, Up and hopefully not away.... My Polytunnel

Post by Conifers » Wed Oct 21, 2009 11:42 pm

I shall watch the gale warnings for southeast England with interest from now on . . . :lol:


User avatar
bev
Posts: 900
Joined: Mon Mar 16, 2009 6:30 pm
Location: stevenage

Re: Up, Up and hopefully not away.... My Polytunnel

Post by bev » Thu Oct 22, 2009 2:20 am

nice one dave icon_thumleft

very intuitive with the pics, hope it lasts a few years. i'm sure there must be a way to make a new cover even if it involves a massive sheet of clear plastic and a few folds!

cheers

lee
come on you spurs


Post Reply