Cheapest supplier profile metal sheet roofing?

[Pord]

Morning all

First post, am in the early stages of building a 6m x 4m workshop in Scotland (near Glasgow). I'm looking for the cheapest supplier of profile metal sheet roofing plus flashings and rooflight. I've had a few quotes and Rhino Steel Cladding are so far the lowest. The downside is that the cost of transportation from so far away is understandably high. Anyone have personal recommendations, ideally somewhere closer to home?

By the way, I've looked at reclaimed stuff on Gumtree, ebay etc and it's all been a bit tatty and random, so that doesn't look like an option.

Thanks

Pord

 

[CHJ]

Have you found e-roofs, No idea regarding relative costs and transport etc. but I've purchased from these folks several times including Galvanised profiles and been satisfied with the quality and service.

https://www.eroofs.co.uk/home-er

 

[Pord]

Great recommendation, thanks. Hadn't seen this supplier before.

 

[Hornbeam]

Do you really want the cheapest?I have worked in metal cladding for nearly 30 years advising 4 orf the largest cladding system manufacturers in the UK so mainly very large sheds but same principles for small ones.
A budget price for a 32/1000 profile quality sheet from Tata steel would be about £10 per square metre inc Vat
Are you building an insulated construction which would work out about £20 or you could buy a composite panel which work out about £25 to £30. If your not doing an insulated construction you will be far more prone to condensation.
As a cheapest budget price, you need to be looking at around £500 for the roof dependent upon construction. Using cheaper or second hand sheeting is false economy
Nearest supplier to you is probably Cladco in Glasgow prices are based on their quote to me this afternoon
If you want any advice drop me a pm
Ian

 

[Pord]

Thanks Ian, very much appreciated. £500 would be very welcome, as I've had two quotes of around £750 + VAT. One came with an additional transport cost of £200. The best price so far is £530 plus VAT delivered from the midlands, so presumably someone closer to me could potentially do it cheaper. I've tried emailing Cladco (the Glasgow version) without reply, but will try them again.

The building will be insulated.

 

[Hornbeam]

Hi Pord.
The first decision is do you want a composite panel with PIR foam insulation which will be more expensive but might be simpler to fit or do you want a built up system, where you will use 2 skins of material with a cavity containing glass wool quilt.
I would recommend a trapezoidal 32/1000 profile as it is much easier ti fix than a sinusoidal profile. Outer sheet for a built up system should be 0.7mm S220 steel. With a colorcoat leathergrain finish this will be good for at least 25years. For a built up you can use either a white steel inner sheet or could use a water proof OSB. You should ensure this is laid to be as air tight as possible or install a membrane above it in the cavity
Steel can be laid as low as 4 degrees so you can have an almost flat roof but will need to consider purlin strength. Is your design a mono pitch or duo pitch roof?
Use stainless steel fasteners with epdm washers and valley fix. I would not recomend crown fixing.
Ian

 

[Pord]

Thanks again Ian. The roof is monopitch, initially designed at 10deg for anti-drip but now that I've decided to insulate and line the roof I'll ditch the anti-drip coating and may drop the angle a bit. The lining will be (from inside) Smartply, cavity insulation (poss wool-based) , breathable membrane (prob Ultraperm), a ventilation void then the metal roof sheets.

 

[Hornbeam]

I would probably go for about 6 degree pitch which gives you a bit of leeway if anything is slightly out.
In general for large metal sheds we dont use membranes unless using perforated acoustic liners. You should focus your effort on getting the smartply liner as air tight as possible so concentrate on sealing all joints. This will reduce any warm air leakage into the insulation cavity. Warm air will carry more moisture and heat. If you get the sealing part right, you dont need the breather membrane. I would use a standard glass wool quilt insulation but would overfill the cavity so if you have a 160 cavity use 200mm of well lofted quilt. Outer sheet should be sealed with mastic tape sealant. Use EPDM or PE vented filler blocks ate the ends of the profile.
If you need drawings I have a library of standard drawings in work either as CAD or pdf which I can e mail you.
Good luck with the build
Ian

 

[Pord]

Great input Ian, much appreciated. I'd prefer to play safe with a membrane and not rely solely on my ability to perfectly seal the OSB. However, can you clarify what you mean by the 'outer sheet'? I have a joiner friend who advises I line the roof cavity on both sides with OSB, the outer skin then having the membrane and finally the metal sheeting applied.

 

[Hornbeam]

There are 2 types of membrane.
What you want is one which goes over the lining sheets of OSB and underneath the insulation(on the warn side) to provide air tightness and prevent the passage of water vapour into the insulation cavity this is known as a VCL.
If you had moisture penetrating into the insulation the approach was to install a breather membrane on the cold side of the insulation, which allows water vapour to pass out of the insulation but does not allow water back through. If you do this you then have a vented air cavity above the breather to take the moisture away.
The better approach is to prevent moist air getting into the cavity (workshop should be dry) and have a fully filled cavity.
There is absolutely no need for an outer OSB sheet, you are just adding cost and complexity to the construction. A standard 0.7mm 32/1000 painted steel roof profile should be fully walkable at around 1800mm centres and also be non-fragile.
Ping me an e mail and I will send you my works number/e mail so I will just treat it as a works technical enquiry (no charge)
Ian

 

[Pord]

Thanks Ian, have emailed you.

 

[Pord]

Did my email reach you Ian? I sent it on 6 Feb.