I am going to use Good Stuff gap filler in a can to fill some holes in the ceiling of my unventilated basement (small windows do not open). Do I need a $30 Home Depot respirator, or is that overkill?
What do you expect this respirator do absorb or filter?
It's overkill. There are so many materials in your home and in the packaging of the things you bring into your home that give off small amounts of gases that you can't protect yourself from all of it...unless you want to wear a respirator 24 hours a day.
why not caulk & backer rods?
seals better & longer than foam.
no to the mask.
best of luck.