Roof panels 'curling'

[Swaitsy83]

Hi all,

New to the forum. I've a question about corrugated bitumen panels. I've recently fitted them to the garage roof, to my knowledge correctly. There's no purlins, there never were on the old roof due to such a gradual pitch so the panels are fixed straight to the wood planks that run over the joists.

As far as keeping the roof leak free they've done a great job, however I've noticed after a few days they've started to curl up lengthways along the panel edge between the fixing nails, where each one overlaps.

Is this a problem? Will they settle again? We've had nothing like any extreme changes in temperature if that's a factor? I didn't expect as much distortion after just a few days being honest, granted I live in Scotland so you take whatever dry weather you're given with outdoor projects. I've seen these panels warp and sag on other roofs but not curling up, almost like they're trying to curl into a cylinder if they weren't fixed down.

I've attached a picture so you can see what I mean. Doesn't look too bad now but they are continuing to curl up. Any and all advice is appreciated cheers.

 

[catlad]

Not suitable if not adequately supported! Tony 1865 isn't a fan.

 

[Swaitsy83]

Ok. I'm not entirely sure what sort of additional support they would need. They're lying flat on a wood planked roof. They're not sagging because there's no void space underneath for them to sag into. They're arrow straight, just curling upwards along the edges. Obviously I can't pin the edges as that's where the water runs down them.

 

[noseall]

they are continuing to curl up. Any and all advice is appreciated cheers.

Those corrugated sheets are as low end as you can get. Some may eve argue that they are unsuitable for their purpose of which I'm in agreement. In order to overcome the extremely poor quality, they have to be fixed to within an inch of their lives.

Yes they will continue to misbehave until the next named storm arrives.

 

[Swaitsy83]

noseall thanks. Unfortunately that was my initial thought being honest with you.

 

[catlad]

Ok well if they are supported all the way ( which is good ) Why the odd ball fixing arrangement?

 

[Swaitsy83]

Ah that aye, well it looks a bit oddball because the first row of panels were fixed down at the end and then the middle, then the overlapping layer has been put down with a larger overlap than planned, making the middle studs appear off centre. This was to try and use whole panels so I wouldn't have to cut excess off.

Where the nails go every second corrugation is the middle of that panel. Granted in hindsight, could have been better arranged. But it looks like I'll be adding more nails anyway, based on nosealls advice.

 

[tony1851]

@op; sorry to disappoint you at this time of day on the Sabbath but within a couple of years, I fear you will be ripping those off in disgust; they are dreadful.
A few years ago, I fixed them on a 15' x 15' workshop in our (sheltered) back garden facing east (all our rain comes from the west). Despite fixing them as per the book, they started curling up at both the sides and ends and within a couple of years I was tripping over the buckets.
My roof slope was also slightly steeper (8°) than yours appears to be.
They are not dimensionally stable, which is not surprising as they seem to be made of a mixture of bitumen and wood fibres.
I later replaced mine with coated steel panels and have had no problems since.
Commiserations; put it down to experience.

 

[Swaitsy83]

Thanks. Them's the breaks. If I can make them last for a while then they'll do for now I suppose, if I can come up with a way of keeping the edges down. Hey ho.

 

[Alec_t]

if I can come up with a way of keeping the edges down.

Put a brick on top? Not very elegant, but might help to prevent rain ingress.