Furnace Vent Thimble

[Vette10R]

Hey guys I have my garage furnace vented straight up through my roof. I haven't insulated around it yet and have not sheetrocked the garage yet. I plan on rocking this spring/summer so I need to button up around the ventilation.

I am going to sheetrock the peak so the ceiling will be pitched with the roof. I have the furnace vented with class B vent pipe but I believe I still need a 1" barrier around that for the insulation and rock to **** up to. I took a piece of 6" single wall vent pipe I had laying around and tried to match the pitch but failed tremendously! I've been looking online for a pitched or adjustable thimble to install but all I can find are straight thimbles.

Does anyone know where I can get a pitched or adjustable thimble or can you give me some ideas or pictures on what I can do that will keep it code?

 

[usdemt]

What size vent pipe? Single wall class B? What is the roof pitch? When I vented mine through the wall the stock thimble I got from Menards still was plenty big for the pipe it was designed for and I just sealed it with high temp silicone. I your roof isn't that bad of a pitch a stock thimble may work, or worse case you offset the two pieces and wrap the difference in steel vent pipe. My inspectors are picky but they still didn't care what made the 1 inch gap as long as it was there and protected from the insulation. For the record though I am the furthest thing from a HVAC guy I just shot the breeze with my inspector while he was here.

 

[Vette10R]

I'm running 4" vent pipe.

Class B is double wall not single.

I just went out to measure roof pitch and it appears to be 3.5X12. Is this posible? Garage was built in 1969, it is kind of a weird roof but I might of measured wrong?

It's currently vented straight up through the roof but there is no insulation near the pipe. I want to finish up the insulation and sheet rock.

I need a thimble that I can mount to my roof trusses that match the pitch of my roof (Possibly adjustable?) And the vent pipe can run straight plumb through it.

Is there anything on the market like this or will I need to make something? I can't find products or even pictures online...