Corrugated shed roof repair

[Stevie D]

Hi folks, time for me to play gardener masquerading as builder again.

I've attached a photo from a job I'm working on at the moment. The corrugated metal (galvanised steel?) roof of a shed where I work is getting rusty, so I took it upon myself to anti-rust prime and grey-bomb it. If at any time it was galvanised, 95% of the galvanising has worn off / failed, exposing ferrous metal to the elements.

However, not all of the roof is metal. You can see in the bottom half of the image that the metal sheets are interspersed with semi-translucent plastic sheets. These are showing their age as well. When I put a non-unreasonable amount of weight onto one of the sheets, it broke, as you can see in the photo.

I intend to get some replacement sheets for that section and put them on myself. I need to ask for the following advice, please:

- The roof was built so that the metal sheets overlap the plastic, rather than vice-versa. Does it matter if I put on a plastic replacement so that its edges overlap the metal?

- Do you have any tips for getting the old fixings out in such a way as to cause minimum damage to surrounding elements?

- What fixings do you recommend for attaching the new sheets?

Thanks in advance,

Steve

[dewaltdisney]

Shed roofs are seldom easy, I have recently refelted mine and it was a pain. The problem with the translucent panels is that over time sunlight makes them yellow and brittle. The best way to approach this is to nip the rood nail heads off with an angle grinder and remove all the sheets. Plan your roof layout so that the overlaps channel water from top to bottom. Have a look at Onduline roof panels to replace the galvanised. This job needs to be presented to the owner as future proofing them as repairing the existing is a false economy. Just my view.

DWD

[Stevie D]

Shed roofs are seldom easy, I have recently refelted mine and it was a pain. The problem with the translucent panels is that over time sunlight makes them yellow and brittle. The best way to approach this is to nip the rood nail heads off with an angle grinder and remove all the sheets. Plan your roof layout so that the overlaps channel water from top to bottom. Have a look at Onduline roof panels to replace the galvanised. This job needs to be presented to the owner as future proofing them as repairing the existing is a false economy. Just my view.

DWD

Thanks DWD. The more I attack this job the more I have the horrible feeling you're right about complete replacement being preferable to repair. The problem is I'm already quite the way in, in terms of sunk cost (paint, hours). I got some plastic corrugated at B&Q earlier today to replace the sheets you can see in the picture. However, it turned out the ridge-to-ridge length if you imagine the cross-section of the corrugation was too long on the new stuff. It wouldn't have matched up with what's already on the roof, which has a ridge-to-ridge length of 77mm. I'll have to shop around and see what's available in that gauge, although the aforementioned creeping feeling tells me that's a gauge no longer in production...

[dewaltdisney]

What a pain, these jobs are seldom easy. Good luck getting it sorted

DWD