Best Way to Secure My Polytunnel?

I have just bought a 6x3 metre poly tunnel . In order to secure the base frame to the ground I am thinking of bolting the base frame discs (photos) to a concrete base. Each side of the base frame has 5 discs and the holes in either side of each disc are approx 20mm in diameter. I don't expect to be using bolts the same diameter as the holes as I was thinking of using smaller bolts; but with a washer large enough to cover each hole. I am not sure whether to make each concrete base 6x6, 9x9 or 12x12 (inches). The depth approx 9 inches.
What do you think?

THANKS

 

If you intend drilling and bolting down to concrete pads I would suggest the biggest size to avoid cracking when drilling, chemical fixings might be better than the expanding type.

 

Hi,

You are talking about a lot of heavy and expensive concrete to go all around a 6x3mtr polytunnel !

What probably would be better is to dig 10 holes for the fixings and fill them with concrete.

Though agree with @pete , you really need advice from someone with good experience of polytunnels.

Did the polytunnel come with any suggestions / instructions for the base.
Looks lke there are many ways to attach it to a base, is yours going onto bare soil ?

Polytunnel Foundations | Timber + Concrete | First Tunnels

 

Sorry for the late reply: I've been away and decided to put it up when I got back rather than rush.

So the poly tunnel will be going into bare soil. There are fixing down pegs that can be bought from the company I bought the tunnel; but I think they will be inadequate.
I will dig 10 holes and fill them with a concrete mix. I will probably then use expanding rawlplugs to secure the base frame

 

Hi,

Sounds a good plan , though always a bit wary of those bags of PostMix, they can be very easy to use but sometimes they can set quite soft ; prefer a standard mix of sand , gavel and cement, but a lot more heavy work ... ?

Looking on Ytube there are lots of videos about base fixing, a lot seem to use treated wooden stakes and cable ties... worth a look ?

 

I have seen pictures of poly tunnels secured using wooden stakes and duct tape and that would seem the easier option; however the inner side of the base discs would have to be cut off to make them like a semi-circle. This would then allow the stake to be parallel to the frame rather than leaning out if the base discs are not cut.
I was recently speaking to someone who was builder and he recommended the expanding rawl plug into concrete bases method because the stakes would eventually rot. Although bolting it down means ensuring all the concrete bases are level with each other; whereas using stakes and duct tape this may not be necessary as I could adjust the frame up or down on the stakes.

Another thing I have thought of is that in high winds the stake method might be stronger because they extend up alongside the frame providing more support and rigidity to the poly tunnel. In contrast, the bolted down method does not offer this advantage.

 

Hi.

Afraid we cannot suggest the best fixing method for you, seems there are lots of methods with things like Ground Screws and Anchor Tubes etc etc.

What do the manufacturers of your polytunnel suggest ?

If you need to get concrete pads level, which are a long way apart, apart from a very long and expensive spirit level, you can buy a length of these boards to use as a straight edge with a small level on top of it.
Wickes White Furniture Panel - 15mm x 150mm x 2400mm | Wickes.co.uk

 

All I will say is it's surprising how quickly, so called, treated timber rots down these days when in direct contact with soil.
I put my second hand green house on timber and to be honest I should have taken it down after 7yrs as the timber needs replacing, it's still there but i will have to bite the bullet one day.

 

If you are concreting, the best way would be to sink lengths of steel tube ,fill with concrete, encasing these :
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thereby avoiding the expansion cracking the (soft) concrete.

 

I use these, thunderbolt/concrete bolt. Just drill the hole and screw in, very secure, easy to put in and take out

 

They have only got one in stock and it's in Stoke.