Car Port Roof Repair

[yottie]

I have quite a large carport with a narrow gap in the middle about the size of a third of a 6 foot sheet, due to weather damage.
I can easily get to the gap from underneath to refill and repair.
Is there any way I could, having replaced the sheet, fix it permanently from underneath.

 

[Wayners]

Polymer grab to stick repair sheet down as it would have to be on the outside and larger than the gap.. Have to find something long enough to push a weight over to push sheet down I'd guess. Don't know how long it will last. Maybe use a clear polymer. CT1 or stixall type

 

[JohnD]

A sack filled with gravel would mould itself to the shape, to weigh it down.