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

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

Post by Dave Brown »

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
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Roll on summer.....
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Eddy

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

Post by Eddy »

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
themes

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

Post by themes »

icon_thumright looks worth all that effort. Its a clever idea recycling all those palm leaves very ingenious.
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Dave Brown
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Re: Up, Up and hopefully not away.... My Polytunnel

Post by Dave Brown »

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
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ElTel

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

Post by ElTel »

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

Post by Dave Brown »

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
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Dave
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Dave in Warrington

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

Post by Dave in Warrington »

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

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

Post by SteveW »

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?
bobbyd44

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

Post by bobbyd44 »

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

Post by redsquirrel »

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
mushtaq86

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

Post by mushtaq86 »

Looks great Dave. icon_thumright icon_thumright icon_thumright
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Dave Brown
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Re: Up, Up and hopefully not away.... My Polytunnel

Post by Dave Brown »

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
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Roll on summer.....
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derrick

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

Post by derrick »

Looks realy good Dave how big is it strong base on it . I just havent got the room .
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Re: Up, Up and hopefully not away.... My Polytunnel

Post by Conifers »

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

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

Post by bev »

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
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