Extended depth wall thimble?

[P38X2]

I'm POSSIBLY looking for an extended depth wall thimble, preferably with an OAK hookup, for my basement stove.
I need to clear a drywalled 2x4 wall, approximately a 2" gap and an 8"-10" concrete foundation wall.

I say possibly because I may have it covered sufficiently DIY style.

My current thimble setup consists of an 8" stovepipe section passing through the walls from slightly proud of the drywall on the inside to flush on the outside. The pipe is screwed and RTV'd together. On the outside of the thimble around the hole in the concrete, stud wall and gap between the 2 walls is Roxul batting. Same goes for the space between the thimble and vent pipe. The thimble is secured and flanged so it cannot slide in or out.

What say you guys? Is my butt covered? I can't find anything remotely close to deep enough for my application and I didn't want to frame a box into the stud wall (so that I was ultimately only passing through the foundation wall), although in hindsight it would have been much easier.

 

[kinsmanstoves]

take a standard wall thimble and add a piece of metal to fill in the gap.

Eric

 

[P38X2]

Thanks, Eric.

That would work nicely but is it necessary? Does my DIY put up any red flags? I should've asked in my first post if the thimble has to meet an actual standard such as UL. That is my primary concern. I guess I can infer from your post that it doesn't as modding a "factory" thimble would negate any rating from the man.

 

[kinsmanstoves]

Depends on how you look at it. I would think the main concern is clearance to combustibles. Other than that I would say your good but as my wife says, "I been wrong before".

Eric

 

[SmokeyTheBear]

You might want to run that by the code folks just to cover your hind end.

Eric said it, the main concern is clearance to combustibles.

 

[P38X2]

Thanks, Smokey.

I was waiting patiently for a code comment from you. I was thinking the same thing. Not to ask a stupid question but would you recommend I call the town building inspector, fire dept or stove shop? I'd rather not get the town involved as my property taxes are already in the holy chit range. I'm SURE they'd find something to justify another increase

I'm no authority but there's no doubt in my mind that the thimble is sound and all clearances have been met. If anyone chimed in and said the thimble MUST be tested, rated and approved, that'd be a different story.

 

[SmokeyTheBear]

The town building inspector just describe the "proposed" method and see what they say.

It is common for them to get questions about all kinds of such things.

You could also talk to the vent manufacturer.

In general you are supposed to use a tested and listing certified system when one exists.

 

[P38X2]

Good idea. I'll do that. Thanks again.

 

[MSmith66]

I'm POSSIBLY looking for an extended depth wall thimble, preferably with an OAK hookup, for my basement stove.
I need to clear a drywalled 2x4 wall, approximately a 2" gap and an 8"-10" concrete foundation wall.

I say possibly because I may have it covered sufficiently DIY style.

My current thimble setup consists of an 8" stovepipe section passing through the walls from slightly proud of the drywall on the inside to flush on the outside. The pipe is screwed and RTV'd together. On the outside of the thimble around the hole in the concrete, stud wall and gap between the 2 walls is Roxul batting. Same goes for the space between the thimble and vent pipe. The thimble is secured and flanged so it cannot slide in or out.

What say you guys? Is my butt covered? I can't find anything remotely close to deep enough for my application and I didn't want to frame a box into the stud wall (so that I was ultimately only passing through the foundation wall), although in hindsight it would have been much easier.

For any install that I have done with a thick wall, I have used 24 gauge 6" black stove pipe to extend the wall thimble. Most pipe manufactures will recommend it.

 

[boosted3g]

I had the same exact situation with my install and was advised by duravent to use a peice of pipe to fill the gap. If memory served correct i just used a 7" diameter 26 gage pipe and cut to length.

 

[P38X2]

I popped in my stove shop today. One of the techs advised me to do what you guys have suggested. He said my current setup is more than adequate and that I definitely did it the hard way. Seems to be on par with my typically MO

Thanks for the replies.

 

[SmokeyTheBear]

Hey nothing wrong with going the extra mile.