What kind of thimble do i need?

[bholler]

It is a new (display model that had one tiny burn allegedly) Nectre N550. Clearance to combustibles is 10” as per the label but i’m looking to put it around 7” since it’s 100% non-combustible wall.

That said, i’d rather not see the stainless portion, just the black stove pipe and trim ring. Based on Bhollers 1.5”-2” suggestion i think that’s possible. So my current plan is to get the metal framing in place and measure, then figure out my rough pipe length needed. Any comment on whether to pack the thimble with cement in a roughly 12” square supported by the framing?

To do a proper masonry passthrough it isn't a 12" square. It is 12" past the thimble. So the square would be 12"+6"+12" or a 30" square. You are doing a non-combustible wall so that isn't required but I would fill around it with mineral wool insulation

 

[NorEaster603]

To do a proper masonry passthrough it isn't a 12" square. It is 12" past the thimble. So the square would be 12"+6"+12" or a 30" square. You are doing a non-combustible wall so that isn't required but I would fill around it with mineral wool insulation

Got it. Any reason to use mineral wool vs fiberglass?

 

[Woody Stover]

Yes that is the T from the stainless liner. Looks like he ran it through another piece of pipe that is cemented in place. Not sure if this is the “correct” way or not but for the money paid i sure hope so…

Yeah, I think my SIL's friend paid like $1000 for the install, but it appears they didn't elect to spend much on materials. 😒 I thought about seeing if he wanted to demand a refund for a not-to-code install, but we might need that dealer to contact PE if the need arises..

 

[Woody Stover]

Got it. Any reason to use mineral wool vs fiberglass?

Mineral wool is fireproof.

 

[bholler]

Got it. Any reason to use mineral wool vs fiberglass?

What he said. It is rated for the proper temps. If you use fiberglass your wall is no longer non-combustible

 

[NorEaster603]

What he said. It is rated for the proper temps. If you use fiberglass your wall is no longer non-combustible

Glass burns?

 

[bholler]

Glass burns?

It probably won't see high enough temps to actually burn in this application but it can absolutely melt.

 

[NorEaster603]

It probably won't see high enough temps to actually burn in this application but it can absolutely melt.

Good point. Ok well thanks for all the help! I’ll get stuck in and update this as i go.

 

[Woody Stover]

Glass burns?

An I-beam won't burn but steel wool will.