It should be good to go for at least 5 years, possibly much longer as it is an acrylic fabric like Sunbrella?  For cleaning/maintaining/retreating later on use:

http://www.sunbrella.com/cleaning/marine-tops-covers.php

YMMV,

Mr. BZ-nono on the Scotchguard

On May 23, 2011, at 9:37 AM, ralph meyermann wrote:

> Hi.all I've purchased a new german canvas from bus depot is there a
> treatment to help it shed water or stay dry? I don't know if a scotch guard
> treatment will help or not? Thanks