Beginners Tunnel

I'm on the look out for a beginners tunnel. I want to grow some veg and use it to plant flowers and shrubs from seed.

I have room for a 4x2 tunnel. I saw this one on amazon.


I really don't like the look of the green cover and was thinking of buying this and just using the frame. I'd buy clear polythene to cover it.

I have a few questions:
Will this plan work?

Is 25mm strong enough?

Do you know of anywhere I can buy frame only in this sort of price range?

I would sink the door posts into concrete to make a solid frame.

Any recommendations on the cover, where to buy and what to look out for?

Any tips of anchoring this kind of tunnel? I was thinking of digging 4 pits and filling them with concrete and leaving a hook exposed a few cm below ground level. I could tie the tunnel to these 4 hooks. Also I could bury the bottom of the frame a few cm below the surface?

 

These are good starter tunnels as long as you strengthen them first and know their limitations.

The zipped doors are useless and will fail at some stage so the idea of putting in a timber door and frame and anchoring that in concrete is a good one, many of us have done this. Build your door frame and door and bolt it to the top of the hoop, before putting the cover on, then when the cover is on you can staple the cover and batten over the top of that to fix the cover to both door and frame, then simply cut around the door carefully.

The height of these tunnels can be restrictive and if you bury the frame you will lose height from the 6ft tall overall size.

I have had 3 of these my last I built two raised beds then mounted the tunnel on top of those to give me extra height, the raised beds where fixed in place with stakes, the tunnel fixed to the bed for stability.

Use the cover that comes with it for a year or two whilst you forward plan changes you wish to make to suit how you use your tunnel.

I'm pushed for time right now but I will add some photos here later today which will help explain the above more and I also have shots of this type of tunnel covered in real polythene too.

Steve...

 

Hi,

Seems you have given up on the idea of a second hand greenhouse ?

Not sure we would want one of those tunnels in our garden, not the nicest looking things, though depends where you can site it.

As @Steve R mentions, polytunnels do have their problems.

Though not something I would normally suggest, as think a greenhouse by a well known maker is a better long term purchase, but one of these 8x6 ft new greenhouse may be an option in the sub £200 market place ?
Have previously seen posts somewhere in forum saying they are not that bad, might be worth searching for them.

 

Thanks for the advice. I could put in 6 x concrete anchor points and keep the tunnel at ground level.

 

I was hoping to use the tunnel in a temporary location as I haven't finished my hard landscaping. I need to start producing some of my own plants to keep the costs down and I have a large area to plant. I can get a bigger tunnel for less money.

 

If you intend to grow plants and veg long term then I would get the site for the permanent greenhouse / polytunnel prepared and install your longer term option from the start.

The issue (if it is an issue) with growing from plants from seed is that half a seed tray grows into a full seed tray which grows into 50 plant pots, then 50 bigger plant pots. Before long you've outgrown your space (saying this, having very quickly filled an 18' x 30' tunnel this year)

I had a 4m x 2m tunnel inside our main tunnel and I wouldn't be happy with it outside. As Marley Farley says, the fame isn't that strong and the cover will not stand abuse. The cover is tailored to the shape of the frame whereas clear polythene would need to be stretched over a frame that isn't very rigid.

What seeds are you intending to sow this late in the season ? If you are intent on installing a tunnel as your image, could you hold off until next spring and spare it a winter ?

Have you considered knocking together a cold frame as an interim solution ?

We installed a First Tunnels polytunnel and the difference in construction to the smaller tunnels is night and day.

 

Yes

Yes. I have three 3 x 6m tunnels with 25mm galv frame and they're far superior to the white plastic coated/painted? smaller dia frames that used to rot after 2 or 3 years.

No, but the same 4 x 2m tunnels are usually cheaper on ebay (even from from same suppliers as on Amazon).

Buy one from there and immediately resell the cover on ebay to get the cost down further.

That would work, but I would set an L shaped galv strap in a conc pad and screw it to the frame.

@Steve R might have a supplier in mind.

Use galv steel L shaped roofing restraining brackets that are pre-drilled, the bent end cast into conc and the other end screwed to your door frame.

If you discard all the nuts and bolts you receive with your tunnel and replace them with longer ones from Wilko (fill a 'pick and mix bag'), you can then fix all sorts of stuff to the inside of you tunnel, such door heads, internal bracing, and holding down brackets along the long sides at 'hoop' intersections.

If you could fit a 3m tunnel in the space available, the length of a 6 x 3 tunnel can easily be reduced, either by using a new sheet cover, or adapting the fitted green mesh cover.

 

Here is my version, erected in 2015. Both cover and frame are still going strong because it is put up well, and well supported. The frame was rested on battens fixed to the bed edgings, the bed edgings where staked to the ground. The cover was put on and stapled to the battens and around the door frames, then battens screwed over the top. The overall idea is to keep it all tight, if it starts moving around in wind that can make it even looser, and liable to fail. This setup has withstood 70-80 MPH winds every winter since 2015 and is still going strong. Cover is just starting to degrade a little but I would easily get another couple of years out of it yet. But I am moving it this winter so will go for the polythene route then.









The one below is my neighbours tunnel at the allotment, I put the above tunnel up in March 2015, then in April the same year we changed the cover to full plastic. It is still on and in good condition as is the frame. These frames aare good as long as they are secured well.

This one is Billy's tunnel


Here is my tunnel this spring with my tunnel within a tunnel system for early seedlings and all my potato and dahlia pots laid out.







I also have a 28ft x 18ft "proper" tunnel that I use but I would not be without the one above, and this is why I am moving it and keeping. I have already bought the plastic for the move and I got that from Robinsons polytunnels chiefly because it was their summer sale. Plastic I bought a few months back for and big new cold frame (yet to be built) was bought from First Tunnels, as was the plastic on BIllys tunnel above.

Good luck whatever you decide to do...but make sure to post some photo's here to add to the overall knowledge.

Steve...

 

I'm hoping to use the tunnel to bring some plants in for the winter and then hope sow seeds from the spring time.

 

Thats a solid looking frame Steve. Its great to see it without the skin to get an idea of the method you used. Thanks for taking the time to up load those photos, I'll be able to refer back to them when I start building mine.

 

Thanks all for taking the time to give me your advice, I really appreciate it. I've went and bought the foxhunter 4m x 2m. £117. I'm going to look out for a clear polythene cover for it mainly for the aesthetics of it because it will be visible from the front of my house. I've started to clear the site and have got water to where the tunnel will go. The tunnel will run directly north/south (long edges facing west & east). I will get some photos when the site is clear. I won't have the frame until the end of next week, is there anything you guys would advise me to do to the ground once its cleared?

I still need to get the polythene, any recommendations on that front would be appreciated. What size sheet should I look out for to cover 4m x 2m?

 

That sounds like a dandy size. I don't know supplkers over there but here, there is usually an aid to help order and set up like a custom calculator for figuring out the size you need. It's likely on the page where you selct your plastic.

Good luck and please keep us updated.

 

For the polythene First Tunnels or Robinsons tunnels are reliable, but a few things to consider first.

How will you fit the cover, trenched in or base rail?

Trenching in requires running the plastic over the top of the tunnel, down the sides and into a ditch, then along the ditch then at least part way up the other side of the ditch. You need to know the measurements of your tunnel to order the correct size. You need to know the overall height and length of the tunnel, and the measurement "over the top of the hoop" plus the measurements for the ditching on either side to be added. The "over the top" measurement you can only measure when the tunnel is up.

The base rail option means you fix the plastic at ground level, hence a base rail, but you need to buy that timber, paint it to preserve it then fit it. Base rails require pipe clamp type fittings to fit the base rails to the tunnel frame, then you need yet more timber as battens to go on top of the base rail to hold the plastic tight. There is a more expensive aluminium option that comes in two parts, one clipping into the other to hold your plastic.

Before the plastic goes on you need anti hotspot tape to go onto the frame because in hot weather the frame heats up and quickly degrades the plastic that is in contact with it. So anti hotspot tape must go all round all of the hoops and along all cross bars too, the end hoops of the tunnel most have tape around it and also at the front too as the plastic wraps round.

It is not something that you cannot do, but it is something that I would advise you put off at least until next summer when better weather is expected and you can learn which method you want to go with and price them before going forward. Get your tunnel, put it up and fit the supplied cover, for now.

Steve...