We took out old drywall in bathroom and put in recessed cans from Home Depot that have a seal to keep out humidity. We also have a Broan OXT series ventilation fan we also bought from Home Depot.
We watched a TOH video on how to install drywall on a ceiling with Tom Silva and he used a spiral scroll saw for cutting holes for the recessed cans. It was a good video but the problem we are having is that the fan and the lights have lips on the units so even if we go out and buy a spiral saw to cut it like the video shows it will only cut to the inside dimensions of the lights and fan. The lips on the fan and lights will prevent the units from pushing through the drywall and allowing the covers to attach properly to the units. The cans we bought were for new construction but they still have a small lip to them.
We had installed the fan two years prior with old drywall but the attic space is so narrow and we had a difficult time installing it and just ended up gerry rigging it knowing we will be replacing drywall. So trying to install them after putting up drywall is not good option. Plus we already installed them to the joists.
Since the cans have a smaller lip to them I can see where somehow we can widdle away where they will pass through the dry wall but the fan has wider lip and not as easy. If we do this then there will be significant gap and do we caulk this to prevent heat loss? Any suggestions as to how to widdle away without too much damage to housing? The fan lips even have holes in the lip to secure it to drywall. We picked this fan because it had the most features we needed. I don't think they make these fans with these options for new construction. I read on another posting that someone cut the lips off the fan housing and not sure how to go about that. It's too bad Broan hasn't addressed this yet.
Is the spiral scroll saw the best option to cut out any drywall holes? We have a dremel and I wondered if there is an attachment for Dremel that would work as well. We also have a router and wondered if there is an attachment that wouldn't rip up the can housing? Since we are slowly remodeling if spiral scroll saw is best option then would anyone recommend one brand over another and/or one model over another and why?