How can I stick polycarbonate to expanded polystyrene?

[memet]

I was given an old greenhouse last year and to save money, I replaced the missing roof with polycarbonate sheets. The problem is that, in high winds, they blow out. The only way I can see of fixing this is to stick them down. However, there was a 2cm gap between the underside of the polycabonate and the frame, which I filled by sticking in some fillets of expanded polystyrene. So, I need something that will join the 2 materials together, and resist the force of the wind. I've tried silicon, which doesn't stick to the polycarbonate. I've spent all afternoon trying to find something with no luck.

 

[masona]

Any photo of the frame etc? There's many difference type

 

[memet]

no, sorry.

 

[masona]

Something like this?

 

[LooPrEvil]

Memet I am not understanding where the 2cm gap is - sorry! But assuming the roof was originally glass, there would have been some clips that occupied this gap and held the glass in situ ?

Could you not put the polycarb in place and then drill some small holes into the frame for some 1" self tapping screws, then put the screws but only screw them in until they are sufficiently in place to stay secure, with the rest of the screw and head left sticking out to prevent wind from lifting the polycarb.

Or put poly carb in position and use self tappers to screw some plastic window moulding in place thus prevent it lifting?