Panel mounting system for steel sheet roof?

[Jinx]

I have just built a small barn and have the roof covered with steel sheets, Cladco box profile 32/1000, now I want to add some solar panels here as it’s an ideal location.

I’m just concerned with the mounting brackets causing leaks, does anyone know the best solution or is it just normal brackets with roofing screws and some CT1 or similar?

[SimonSays]

K2 Mini Rails with CT1?

[Jinx]

Thankyou Simon, that looks ideal.

[Stinsy]

I have no personal experience. However, I've seen loads of systems designed specifically for this. They tend to be made for a particular roof system. Does yours have a name?

[Thebeeman]

Our panels are mounted on stand off brackets, about 3" clearance, and ordinary sheet roof screws through existing fixing holes, they did helpfully point out that the existing roof screws were all rusted through so I spent XXX hours on the roof replacing thousands of the B's as North Dartmoor is very visible from the roof, 2 miles away.
Added: I've just looked at the suggested rails, ours are screwed through the sheet valley not the peak. If you attach to the peak you will not be able to tighten the screw to get a weather seal.

[AGT]

https://voltaconsolar.com/products/meta ... et-mrb-t04

[AGT]

What thickness of sheet as i remember some only want a minimum of 0.7mm

[Jinx]

I have no personal experience. However, I've seen loads of systems designed specifically for this. They tend to be made for a particular roof system. Does yours have a name?

They are Cladco 32/1000 sheets, they seem to be pretty generic and many suppliers do exact matches.

What thickness of sheet as i remember some only want a minimum of 0.7mm

Yes they are the 0.7mm plastic coated ones, a fair bit more substantial than the 0.5mm versions.

Our panels are mounted on stand off brackets, about 3" clearance, and ordinary sheet roof screws through existing fixing holes, they did helpfully point out that the existing roof screws were all rusted through so I spent XXX hours on the roof replacing thousands of the B's as North Dartmoor is very visible from the roof, 2 miles away.
Added: I've just looked at the suggested rails, ours are screwed through the sheet valley not the peak. If you attach to the peak you will not be able to tighten the screw to get a weather seal.

I did wonder about that, the sheets are all fixed in the valleys, however there are some stitching screws that join on the ridges and they seal fine. I assumed it would be valley fixed brackets, where I can pick up the rafters but the mini rail system mentioned above seems fine on the ridges, the promotional video shows industrial setups using this method so it must be strong enough?

[Thebeeman]

The 'stitching' screws are only holding the edge of the sheet down so no great strain. The solar panels could get a lot of wind loading and I would be very nervous if they were attached to just to a single thickness of the steel sheet.

[Joeboy]

I did my latest solar addition using 2" x 2" timbers. Heavily treated, laid out timbers, marked and drilled the peak flats of the corrugated sheeting and fixed from below with 2" screws and M5 s/s flat washers. Each screw spot had a blob of roof sealer. each rail held in place with 31 screws. It is going nowhere and doesn't leak.

https://www.screwfix.com/p/geocel-trade ... 10ml/72630