[Pequod]

I just had the transite pipe removed from my house and I need to install a type B flue pipe from the furnace. There is a chase where the old heat pipe was and there should be plenty of room for the new type B pipe (1 inch clearance). I will be running horizontally for about 8' from the heater in the crawl space into an unconditioned laundry room. Then into the chase up through the first floor, then through the attic and out to the roof. How many firestops would I need in this case?

From what I read from Duravent and others is I will need one from the laundry room through the joists in the first floor into the chase and one as the pipe exits the roof. Do I need another perhaps at the top of the chase where the pipe enters the attic area? I just had a contractor here at the house and he had no idea what a firestop was! Thanks in advance for your help.

 

[carmon]

fire stop for every floor here.......

 

[HVAC1000]

fire stop for every floor here.......

Same here. i kinda can't believe a contractor wouldn't know what a firestop is.

 

[Pequod]

Thanks for your replies. I was astounded as well. Southern CA is full of these types...

So that's one firestop at the first floor penetration and one at the roof? Also, where the chase enters the attic area, the framing is lower in this section than the overall attic elevation and the blown in insulation can fall down into the chase. If I fit and cut sheet metal to extend vertically above the insulation layer will this be safe and comply with code? The chase itself is simply framed and has insulation on one side to weather.

 

[HVAC1000]

if i understand you correctly then yes you can fit a cuff around the flue (at least an inch away) to keep the insulation from falling in on the flue. just make sure as you said to be an inch away from flammables, including drywall

 

[jagans]

Everything I have ever read about flues calls for 2 inches minimum clearance. Has this changed recently? As far as firestop goes, I assume you mean Rock Wool, or unfaced, compressed fiberglass, and not the traditional in wall wood firestops.

 

[HVAC1000]

Everything I have ever read about flues calls for 2 inches minimum clearance. Has this changed recently? As far as firestop goes, I assume you mean Rock Wool, or unfaced, compressed fiberglass, and not the traditional in wall wood firestops.

From my hands on experience with double wall ( B-vent) flue pipes the code ( Around here at least) says only 1 inch from flammables. Also with all brands of double wall each piece has a sticker on them that specifies only one inch clearance from flammables.

 

[beenthere]

The hole is 2" bigger then the pipe. Which gives you 1" clearance all around the pipe. Maybe he is confused on that.