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garage wall penetration

Yeah, that's basically what we'll end up with. This is a Toyotomi boiler. The flue pipe is about 2 1/2 " in diameter. They have a sock that goes over it that lowers the clearance to combustibles to 3". (Don't know what this is made out of, looks like Nomex. Their installation instructions say 3" to combustibles).

We'll cut the sheet rock back far enough and put a sheet metal plate over the hole, and then pass the vent through it and seal it wit the caulk. Just though there must be a better way.

I'm worried about condensation too, but didn't want to box it in and increase the heat build up. All the parts of the vent are stainless, so it should hold up. Anything in the garage is pitched to the outside so any moisture will go out.


  • Paul Fredricks_9
    Paul Fredricks_9 Member Posts: 315

    We have an installation where we need to direct vent. The flue pipe needs to go from the basement, through a garage, and then to the outside wall. We have 2 dilemmas: we need to keep a minimum clearance to combustibles, but we have to seal the penetration in order to meet the fire rating of the garage/house wall.

    Any suggestions?

    We thought a larger sized piece of B vent, with the flue pipe running through it, but then that would have to be sealed. That would make future work on the pipe difficult. Or maybe just have the pipe pass through a piece of sheet metal, with the gap sealed with fire proof caulk.
  • EricAune
    EricAune Member Posts: 432
    Fire caulk

    Not sure about running the pipe inside another. I have had to do this a couple times. Unfortunately each time the garage was unconditioned. We had a carpenter build a "housing" around the vent so there was minimal condensing of the flue gasses in the venting.

    I have used 3M intumescent fire caulking for years. Check with your local code authorities first, they might have a product recommendation.


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  • Bob Bona_4
    Bob Bona_4 Member Posts: 2,083

    take a look at Modine's Hot Dawg thimble kit, Paul. It does have a section of SS single wall 3" impregnated in it for exterior terminations, but the thimble stand offs are really sanitary looking.

    Might have to trim it, just thinking out loud..
  • Big Will
    Big Will Member Posts: 396

    Call a sheet metal guy. Any good shop with a circle sheer can make a ring for that that is fire rated and looks real clean. Even a hand crank circle shear can do it on about five minutes.
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