Source
r/woodstoving•
HC-IIIX

Please help me plan! I'm about to pass my stove pipe through a wooden exernal wall using this method. Is there anything I need to know?

My first post here, so thank you for helping!

I've purchased a wood stove and I need to pass the pipe through a 15cm external, insulated wooden wall of a cabin.

I've found this method which seems affordable and safe. I don't have a big budget for pre-made solutions, but I am very handy so I don't mind building a DIY solution.

http://blog.kominki-batura.pl/montaz-komina-i-piecyka-w-domu-z-drewna/

Essentially, it involves building a fireproof box of non-combustible insulation board to provide clearance around the insulated pipe as it passed through.

Is this generally a good idea?

Should it be filled with rockwool instead of air? (I don't know which is a better insulater).

Any other advice?

Posted May 5, 2022, 6:16 AM UTC

87
seijio•

I think you are supposed to maintain a 2" air gap around the pipe. Take a look at the official part for this method. Maybe you can bend some metal into "U" shapes to give it some clearance between the pipe and pass-though?

Non-combustible materials still conduct heat. Overtime this could lead to a fire. Very low odds, and takes a long time...but it is possible.

2
HC-IIIXOP•

That's a good idea, thank you!

1
linux_assassin•

I don't see anything inherently wrong with the design.

Do not fill the box with rockwool or other insulate; it has a higher R value AND a higher thermal capacity; these are NOT desirable features in something who's purpose is to allow the heat to radiate away without accumulating. You can use rockwoll AROUND the box to help seal it.

Further depending on where you are in the world, make sure that the homebrew solution will meet your insurance company requirements- it would be very awful to have a fire take place and then be told you have no coverage for not using an approved pass through.

2
HC-IIIXOP•

Thank you. That's some great insights.

1
DrYIMBY•

Looks good. I'd put rock wool in to avoid drafts.

-1
HC-IIIXOP•

Thank you. So for fireproofing, rockwool is an acceptable swap for the air?

1
DrYIMBY•

I think it’s fine, but do make sure creosote is not leaking from the chimney and building up in the insulation. That wouldn’t be safe.

1