I have a pair of Sunsetter power-retractable awnings on my house, made with Sunbrella brand fabric. The fabric is holding up well in the Mexican sun, except that the seams are failing.

Replacement awning fabric from Sunsetter is fantastically expensive -- about $700 for my 18-foot awning. Fortunately when I purchased the awnings four years ago I took them up on their optional 5-year no-questions-asked extended fabric warranty. They are sending me a new awning fabric free of charge as I type this. FWIW, I have found Sunsetter's customer service to be stunningly good every time I have needed it.

Since the damage to my awning (see photo, below) is really rather trivial, I am going to repair the existing fabric and save the new one for future need. I will hire someone to stand on a ladder and re-sew the seam with the awning in place, probably for about 200 pesos (~$16 USD).

So now the question: what kind of thread is best suited for strength and more importantly weather/sun resistance?

tanstaafl.

I'd have to guess some sort of sail thread - they have to deal with sun all the time. Is there a marina nearby?

-jk

That's a reasonable idea. Otherwise, look online for "UV resistant thread," such as Star Ultra.