Everbuild Everflex Roof and Gutter Sealant – Butyl-Based Sealant and Adhesive for Roofing – Excellent Weathering Properties – Black – 295 ml

Does exactly what it is supposed to be. Smells very "chemical" and handling isn't as easy as normal silicon. But that's no downside since the task requires high-tech material.

Fixed a Upvc leaking gutter seal, worked a treat and still going strong. Saved me listening to all the BS of a gutter repairer and getting ripped off in the process.

Used to do temporary repair to felt on a shed roof. As others have said, not easy to get out from tube, despite keeping it warm in the house for two days prior to use + warming in hot water on the job. Forget trying to spread it, just squeeze out lengths of it. Bought two tubes, which arrived promptly and were reasonably priced. Managed to stick down the felt, it definitely got harder to do as time went on, as it was extremely cold outside early January 2024..... However, it did the job. I had no option, btw, this repair was necessary.

Works very well, takes some time to cure so to speak but works instantly, I have used this during the rain and instantly stopped the leak in my roof, excellent product, used when replacing the roof on my garage with onduline

Just the job, but it is very sticky!!