Lopi & wall thimble question

[Texican65]

Hi there. my wife and I bought our first home this summer, and it came with an ancient schrader woodstove with single wall stove pipe, which was not installed or set up properly. I replaced the schrader with a restored lopi M380, early secondary burn ideas with an airtight firebox. Anyways, when using the schrader, if I didn't babysit it, it got very hot, very fast, it wasn't airtight and had no clearance from the corners...not very safe. I noticed a couple of times that the drywall where the stove pipe went Into the wall was getting very hot one night, almost too hot to comfortably touch for too long. I damped it down and it cooled off eventually. Kinda scared me a bit, and I quit using the schrader. when I set the lopi up, I decided to use double wall stove pipe to see if it would help keep things cooler.
When taking the old pipe off the wall, I noticed the drywall was only 1/4 to 1/2 inch away from the outside of the chimney pipe that penetrates thru the inside wall. My dad says it ought to be at least 2 inches away. I cut away the drywall around the pipe 2 inches and I ran into a metal plate behind the drywall. I wasn't sure if there was a thimble supporting the pipe, but I think this might be it? Can any of you all tell in the pictures if that's part of the thimble? I think the 8" double wall chimney pipe and adapter is metalbestos brand?

Thanks very much,

Dow

 

[bholler]

It looks like class a chimney and a wall pass thru. It wasn't installed correctly but that is what it looks like. What does it look like on the outside?

 

[Texican65]

Morning bholler, thanks for the response. The pipe that goes thru the wall runs 11 inches back to a T, it goes down to a little flat spot...a clean out dump I think, and then up the side of the house 6 or 7 feet higher than the roof. There's a chase on the outside of the house covering the chimney pipe, and there's no access to the pipe from the outside, other than from the chimney on top of the roof, it's stainless double wall up top too.
I figured it might have been installed wrong, or maybe different code when the house was built in 1991? I think it's too close to the corner of the room. What do you see that leads you to believe it was installed incorrectly? This is a tri-level home, and the stove is in the bottom level, probably not ideal, but it's what we've got to deal with I guess.

Thanks,

Dow

 

[begreen]

There appears to be a few things wrong with the original installation. The hearth is too small for the stove. The old Schrader is supposed to be no closer that. 24" to the brick wall. (36" less 33%). The stub coming off of the thimble should have been longer to project into the room by the mfg. specified distance. This can be 3-6". The chimney stub coming from the tee should have a surrounding thimble or frame that maintains 2" from the surrounding framing. Otherwise it needs to have a 9" air space from combustibles. I'm not sure what pipe brand this is, but here is an illustration using a proper mfg. thimble for Supervent. You may need to do a bit more exploratory surgery to see what they did and you will need to determine the chimney brand. This is what Supervent's wall thimble looks like:
https://www.menards.com/main/heatin...vent-6-black-wall-thimble/p-1444453717845.htm

More general info on passing through a wall.
https://www.hearth.com/talk/threads/chimney-passing-a-chimney-through-the-wall.147754/

The new stove should have closer clearances. Do you know which version of the M380 this is or when it was made? Teh M380-96 has 6.5" corner clearances. If that is your model the hearth size may work. For the Lopi use double-wall pipe to connect the stove. It's less radiant and will keep the flue gases hotter.

 

[Texican65]

Many thanks begreen! It's hard to tell in the photos I provided, but the pipe stub coming off the tee into the room protrudes right at 3 inches. I think that is ok. I hope the hearth isn't too small for the lopi, it's 53x53 and 46 tall. i took the pipe adapter into a hearth store when buying double wall stove pipe, and I showed the man a few pictures, he said its metalbestos. I'm hoping that's a metalbestos branded thimble around the pipe stub in the wall. Maybe I can take part of the siding off the chase to get a better view at how this was installed years ago, without tearing up the interior wall?
As for the lopi, I'm not 100% sure which model of the 380 it is? There is not a label plate or sticker on it anywhere. It has a rear hear shield, and a baffle inside, with secondary air inlets above the double doors. The baffle has 4 firebricks and there's 4 bricks along the side and back walls. Ill let ya know what I find when I take the siding off the bottom of the chase. Thanks for your help, I really don't want to burn our first house down.

Dow

 

[begreen]

Is there a date on the UL tag?

Selkirk makes multiple pipes that often are called Metalbestos. If you use double wall connector (DSP) pipe then there is an adapter section that ties into the chimney pipe.

If you stick with single-wall be sure there is 18" to the nearest combustible.

 

[Texican65]

Yes, I've got the double wall stove pipe now, and I'm using the pre-existing adapter that was being used for the single wall, the double wall pipe slides right over the pipe end of the adapter. However, it looks an awful lot like the super vent chimney pipe adapter in your diagram. There's a picture of my adapter in one of the photos I previously attached. It's the black piece sitting on top of the hearth underneath the chimney pipe sticking out of the wall. The only label anywhere is on a retaining ring that holds the adapter to the chimney pipe. I can check it for a date when I get home.

 

[Texican65]

Well, I was able to pry the siding away from the chase just enough to peek in...couldn't see anything. There was roofing felt or tar paper covering what I think is plywood.

The UL tag on the chimney pipe/ adapter retaining clip reads:

UL listed 98H3 Model SC/58
Part no. JSC6SLB RM 19000

GSW Heating Products Division
Hamilton, Ontario, Canada

And also, looking at the house blueprints from 1990, I don't see this stove or chimney anywhere on the blueprints. It must have been added later. Any idea how or where to look to find building/fire permit type paperwork, or to find out who might have done the work?

Thanks,

Dow

 

[begreen]

That is Supervent pipe. Sorry if I wasn't clear but it's the UL label on the back of the stove I was asking about to see if there is a date or a model number there?

 

[Texican65]

Shoot. There's nothing on the stove, no label anywhere. Only lettering is inside the brass doors, it says lopi, made in Bellevue, wa.

Reading more into the installation manual for supervent chimney pipe, I think I might be ok with this setup. It's type X 5/8" fireproof drywall for the inner walls in this room, there's a wall thimble supporting a foot of stub pipe that connects to the pipe tee, the stub pipe protrudes 3" into the room, it's double walled supervent chimney pipe all the way to the top of the chimney. The lopi will be 3 times as far away from the brick hearth sides. I've changed the single wall stove pipe to double. I'm wondering if this was up to code in 1990, with the drywall less than 2" from the stub pipe, I fixed that though. The way that schrader was installed wasn't very smart, but I've remedied that. I think we're probably ok without ripping the wall or chase apart to look behind the interior wall?

What say ye experts?

Dow

 

[bholler]

I think we're probably ok without ripping the wall or chase apart to look behind the interior wall?

I would not trust it if it were my house. Or a customer of mine. And btw there is no fireproof drywall. Fire rated and fire proof are very different

 

[Texican65]

Ok, well, if you guys don't trust it, I don't either! Just my wife and old man are raggin on me that I'm being overly paranoid, and she's cold.

What's the less painful route? Wreck the chase, the interior drywall, or maybe even have a certified inspector come out with a boroscope or similar device?

Thanks,
Dow

 

[bholler]

What's the less painful route? Wreck the chase, the interior drywall, or maybe even have a certified inspector come out with a boroscope or similar device?

Yes a camera would be helpful but you will also need to open up something to see inside the chase and check for clearances. Regardless you need to cut the drywall back 2" from the pipe anyway so i would start there.

 

[begreen]

Stove placement will probably be ok. I would do some exploratory surgery to discover what was done instead of a proper thimble. If there is none then see how close the nearest wood framing is to the pipe. If 9" or more then a cement board patch will work for now. If not then a SuperVent thimble should be installed to maintain proper clearances.