Our 20+ year-old conservatory roof is made from sheets of 10mm twinwall roughly 850mm wide. The distance between timber joists supporting this is half that distance - with each second joist having a glazin bar to secure the edges of neighbouring sheets. The intermediate joists (i.e. the ones at the centre of each sheet have fixing buttons through each sheet into the joist.
During the winter a number of these fixing buttons have popped up. The brief inspection I've done from a ladder propped up against the conservatory makes me think that the buttons are merely nailed through the twinwall and into the timber joists under the sheets.
There is also evidence of water ingress - possibly from failing joints on one or two of the glazing bars.
I can see four alternative courses of action, listed in increasing cost and hassles:
1.) bang the popped nails back in place, ignore the leaks and hope for the best 2.) replace (all) the fixing buttons with screw-in types. While up on the conservatory (I have no idea if the 20+ y/o roofing will bear my weight: I doubt it) see what I can do to fix the leaky bits 3.) Replace the old roof with a new one, either myself or get someone to do the whole lot. Prob. with 25mm triple, or "X" walled sheets. 4.) Move houseI have a sneaky feeling that although option (2) sounds promising, in reality it won't succeed, or will only appear to work until the next winter, which will end us up back where we are now.