I have called several insulation companies in Northeast Ohio and their answer to my problem is to blow in insulation (as much as will fit) into the joists between my first floor ceiling and second floor flooring at the header in the front of my house.
So far, it does not appear that anyone does any gap sealing or investigation. The house itself is not drafty. Between my new vinyl windows and a high efficiency furnace, my heating bills seem ok. I have however had one frozen pipe in the second floor master bath over the garage and a second frozen pipe in the second floor “kids” bath. In both cases, the plumbers hotshot thaw seemed to isolate the problem inside my house under the 2nd floor flooring between different sets of joists near the front of the house. Even with our heated tile flooring, the tiles along the front of the house are ICE cold. Within several feet, that issue dissipates.
My garage roof has a small attic portion next to where my second floor living space and master bath ends. As the garage roof slopes down towards the front of the house, that roof slope wraps around the front of the house, joining at the 2nd floor wall (creating a crawl space - between the 2nd floor joists, the vertical front wall of the house and the “garage roof wrap around pitch”). I have crawled in that space and have found that the header is about 1/8" (or less) smaller than the joists (leaving a gap for air to get in between the joists) where the garage ceiling is screwed up to the joists.
To top this all off, someone took a 25’ roll of insulation and tacked that up to the 1-2’ vertical wall that is in that crawl space. I also found my 10’x10’ front porch ceiling is completely made of soffett venting material allowing so much wind and air up into this crawl space it actually moves the tacked up insulation roll in the wind.
What I am hearing is that it is simply cost prohibitive to try to even find all the cracks or crevices that could allow air into the joists. It is better to simply fill each and every joist (starting in the crawl space drilling a 1"hole in the header board between each set of joists). While it may not be ideal to have a 10’x10’ porch made of venting soffett material, the key is simply to protect the front house wall and header and garage and not worry about what air is in this crawl space.
I want to make sure I am actually solving my problem this way (as best as can be expected) and that I am not making any new problems.
Looking forward to any advice or guidance, Jeff.