corrugated roofing material

[Bill Wright]

I need to put a car-port-style roof over a chicken yard. It's only about

12foot by 15ft. Can anyone suggest a suitable type of material? This is a windy area.

Bill

[David Lang]

DON'T us clear PVC!

[newshound]

+1.

Corroline / Onduline.

Plastic coated steel sheeting, check on eBay. Comes in various thicknesses, the thin stuff is pretty cheap but needs plenty of support, the proper agricultural stuff is very durable but presumably with prices to match. You can get "windows" to match made from clear glass reinforced sheeting.

Twinwall polycarbonate if you need light to get through, may need extra support to cope with wind.

[Tim Lamb]

In message , Bill Wright writes

Box section rolled sheet steel. 1m wide. Comes in various finishes at various costs and 0.5mm or 0.7mm thick.

Cheapest is .5mm powder coat. Dearest 0.7mm galvanised with plastic top surface.

Cheaper still would be corrugated galvanised steel but you might struggle to find 12 or 15' lengths.

Have a look at the Steadmans of Carlisle site for info.

[Brian-Gaff]

Don't use plastic. I've seen the aftermath of this when its a few years old and the wind gets it. Brian

[fred]

I imagine he will need at least one mid purlin so presumable he could overlap shorter sheets on the purlin.

The corrugated galvanised steel sheet (or corrugated iron as it is known locally)would be my choice.

[Tim Lamb]

Intermediate purlins of course. Lapping sheets on very shallow pitches leads to wicking and corrosion under the lap.

I was also considering rigidity in strong winds:-)

[Vir Campestris]

How windy?

You may need to tie it down well...

Andy

[newshound]

I used to have a field shelter, that's a sort of free-standing shed for horses. I had it tied down, but as it turned out not sufficiently because it was flipped in a moderate gale.

No sign of movement on the onduline roof, which was nailed as per spec.

Then I did the British Standard calc and found, for this 12 x 15 foot structure, the one in ten year wind would provide a lifting force of (iirc) about 2.5 tons.

After that, I gave it 8x8 inch concrete footings all round, and half a dozen 6 mm wire ropes on turnbuckles to the roof trusses, and it didn't move again.

[fred]

We've had no problems using the recommended overlap. No sign of wicking or corrosion and one of he shed is over 20 years old.

Farmers haybarns were made from this stuff for years and I've seen 120 year examples still standing and in good condition. It makes very strong rigid roof. I fact I once saw a hay barn with a curved roof and simple bow string trusses. The strongest part was the sheeting

[fred]

Just a thought but would it not be better to allow the wind to exit the premsises ?

Entire 200ft long chicken sheds, complete with occupants, were lifted and scattered not far from here a while back

[Vir Campestris]

If you raise a roof off the ground, and have no walls, you've got an approximation to a wing. It had better be parallel to the ground, so you don't get any airflow that isn't parallel to the wing^w roof which would give lift.

Of course it needs a slope so the rain runs off. Perhaps you need to build it on a slope too!

Andy