FRP, Roof Leaking, and Delamination

The FRP is only as good as the concrete it's bonded to. I used it some years ago as a temporary repair for concrete bridge piers. We had to do a lot of patching first.

"30 years from now water starts penetrating"
as bridgebuster said, FRP is very strong when it constructed properly. But when you speak durability of FRP strips, Delamination is highly anticipated within few years ! due to weather conditions, moisture penetration, and heat variations effects.
FRP laminates (strips)

If the use of FRP systems to completely seal the concrete surface and moisture and vapor trapped ,that will be end of the strengthening. Therefore in the case of flexural strengthening of beams or of slabs it is recommended to leave a gap to provide to enable moisture escape.

I will suggest you to look ( Retrofitting of concrete structures by externally bonded FRPs, 35-FIB ) and follow the recommendations.





Use it up, wear it out;
Make it do, or do without.

NEW ENGLAND MAXIM