There is no set time frame. I have had a male spin a new web within the hour after mating, and I have had males take 1-2 weeks to spin a new sperm web. Just offer food and water and look for the remains of a sperm web. You might not actually catch him in the act, but if you see some remains of some fairly thick webbing that was proberly a sperm web.
i once had an avicularia male take 4 weeks before he made another sperm web - but he was fairly old. so the time frame may depend on his age as well. freshly molted adult males tend to built sperm webs pretty quick after a mating ime, but seem to take longer as they get older. i didn't keep many males through the whole of their adulthood though, so that only might have been the case with those few i kept until they were eaten.