Insulating Garage Exhust Pipe?

[Samuel Brooks]

I know this is not a woodworking question, but since it's for my new workshop it kinda is . I added 10' to the back of our 24x30 garage so now it's 24x40.

Installation information.
I have a direct vent natural gas powered 30,000 btu heater. It is ceiling mounted and I am venting out a side wall. I am using b-vent and it specifies on the b-vent that I need a 1" clearance. I went with 1-1/4 clearance and I used the red fire caulk between the metal shroud that centers the b-vent in the hole and the b-vent.

My question is this, what can I use to block the airflow around the outside of the shroud that holds the b-vent in place. I still have a gap between the shroud and the siding. Should I just use normal white caulk for windows and doors? I need to fill some gaps that are pretty big since siding is not flat. .

I am not to the point where I can install the drywall, I am still runing the electical and I will need to get it inspected as well as the HVAC inspected including this heater installation.

Any help will be appreciated.

[Al Willits]

Check the code, it probably says 1" clearance to combusibles, then a non flamable material would prob work.

Al

[Samuel Brooks]

Check the code, it probably says 1" clearance to combusibles, then a non flamable material would prob work.

Al

OK, I will call around and see what I can find out. Thanks for the response. I wanted to use the expanding foam to fill in the gap. I figured I could cut back any area that expands too close to the pipe.

Sam

[David G Baker]

I have the double walled pipe through my wall and I build a box around the pipe that was around 12"x12" and the thickness of the wall. I put 5/8" Sheetrock designed for walls that need fire retardant Sheetrock on all of the inside surfaces of the box and a pipe ring around the pipe where it exits the wall.
I didn't use caulking on the pipe but I could have if I needed it. The pipe ring was quite snug and the Sheetrock gave me a smooth flat surface.

[Frank Hagan]

Installation information.
I have a direct vent natural gas powered 30,000 btu heater. It is ceiling mounted and I am venting out a side wall. I am using b-vent and it specifies on the b-vent that I need a 1" clearance. I went with 1-1/4 clearance and I used the red fire caulk between the metal shroud that centers the b-vent in the hole and the b-vent.

Did the installation manual with the furnace say you can use B-vent? I'm no longer in the business, but all the side vent furnaces I was familiar with required non-corrosive venting material. Its important to vent properly with the proper pitch (towards the termination outside) to prevent condensation from pooling in the vent pipe. Regular B-vent tends to corrode, and all the deaths I dealt with were mostly due to venting problems (corrosion, improper material used, squirrels making nests in the vent, etc.) The manufacturer will have the specs for proper venting.

There are sidewall jacks for the penetration.

[Ben Grunow]

I usually cut out a square of siding and install a block of 1" thick wood (with a flashing on top) so the escutcheon has something flat to sit against. Otherwise there is a space for bugs and moisture to move in.

Like the one under the wall sconce in this pic.

DSCN0278.JPG

good luck