Fire blocking a gas vent chase
I’m not sure if this question should go under construction techniques or here in heating/insulation, but here goes. I’m buying a house built circa 1964. There is a gas furnace and hot water heater in the basement. The gas vent/flue chase goes through the basement ceiling, through the main floor, into the attic and out the roof. From the basement you can look up and see the roof. At the home inspection the inspector said this was a code violation and fire blocking was needed. From my perspective, draft blocking also needed as I have no desire to try to heat my vented attic come winter!(there are heating ducts to the basement, although it isn’t fully finished yet). So, the question is, how do I appropriately fire/draft block this chase? My realtor suggested Wonderboard, and one book I looked in said 26 gauge sheet metal. Can I use either of these? Can I split the blocking so I don’t have to remove the flue to get it in place? If I split it, do I just use fire stop rated caulking to seal the seam? Any thoughts, suggestions, or resources to check would be greatly appreciated!
This post, in response to your question, will bump the thread through the 'recent discussion' listing again.
Perhaps it will catch someone's attention that can help you with advice.
"The old Quaker Meeting house is almost 300 years old and as my sawzall made its way into the pegged ancient wood, a smell emerged that told me about dried, cracked things. The ancient Quakers sitting in the well worn pocket of their silence on the darkened pine benches were whispering something to me across the years. Something about why I was here, why we're here. Lord but it was hot. I reached in to clear anything out of what was the sill, nothing but the hardened mud, lime and sand mortar, dust and shadows." -- Jer
Did you get any Ideas yet?
If you make a template of the space with the size of the flue in the location it is. Then lay out flat, make a sheet metal copy but take the pattern and cut it in half, then add additional on each. Say 1". Now if you look at the pattern add 1" around the perimeter. Use this 1" to make a flange? bent 90 deg. You can make a couple of these to place at the first floor and at the attic/ceiling.
If they are made well you should be able to sheetmetal screw around perimeter and join seams.
Thanks, that's pretty much what I was starting to think was the best way to handle it. Not much insulating value, but it would take care of the draft stopping and fire stopping issues. Eventually I think I'm just going to replace the gas furnace with a heat pump and get rid of the flue entirely, but this should work for the time being.
And unfortunately like all projects they just get bigger and bigger.
You have to consider what to do with the HWH vent? Or the additional new direct vent HWH.