Originally Posted by Roof Cleaning Virginia
With all due respect Mr. Stead, that's incorrect. I'm not sure how that rumor has become so wide spread, as many seem to think that 40f is the cut off. It's not. SH simply works slower at low temps, and at some point the cold is too hard on equipment and hoses to be productive. (We've literally treated roofs that had heavy frost on them, of course it melted off on contact)
So to the OPs question the answer is no, it's MUCH slower; but it can be done. With that said, go a little stronger with your SH mixture and be very patient.
Thanks. I hadn't heard that.