help please hearth pad and new stove thimble questions

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.

rosieXdox

New Member
Sep 29, 2021
70
new jersey
this is after they removed the concrete. you see the red flashlight where i’m shining the light on the edge of the terra-cotta pipe, where now there is a gap between the masonry brick chimney and the terra-cotta chimney pipe.

next photo is the double wall pipe that’s cut with insulation sticking out of it.

7F320C54-569E-4F1C-AE7E-102704A8957B.jpeg 3FDFB83C-6560-4BC8-B98E-1CE9BCF5EA67.jpeg
 

rosieXdox

New Member
Sep 29, 2021
70
new jersey
this is the cut pipe the first time they cut it. they cut the wrong end and came back with the other end cut.
if you look closely that’s the hole in the wall and what it looked like with the black circle plate thing taken off.

FF30A45E-D72C-4ED4-92E5-2AEA2CE3F61C.jpeg
 

rosieXdox

New Member
Sep 29, 2021
70
new jersey
the woodstove was put right on the grout line, and the stove pipe (black) from the elbow to the wall is not angles upwards, it’s level.
the clearances aren’t exactly right either. they’re short.

these guys did no measuring at all. they used a magnesite level on the stove pipe but they were measuring the vertical pipe.. idk
they didn’t check the angle of the elbow to thimble pipe angle either.

I asked isn’t it supposed to angle up 1/4” every so many inches? and he said no, that’s the pipe inside the wall.
 

rosieXdox

New Member
Sep 29, 2021
70
new jersey
This company is supposed to be reputable. I asked for them to pull a permit, and called the town to ask if they had revcievex an application yet. At the time they said no, but “let ———— handle it”. (meaning the company we used.
so i didn’t follow up to see.

the guys left today without having me pay, so i have to go there to pay.
they actually made a mistake had to leave and come back with a new stove, and forgot their battery charger here too. so 3 trips would be a lot already. I’ll call and pay. or just go there, since i didn’t get a chance to get a stovetop heat powered fan yet, or thermometer.

Also the stove pipe they used is the telescoping kind, which they screwed directly to the top of the stove. no crimped edge attacher pipe piece. though they had it with them. Instead it’s just pipe over the stoves pipe, screwed in sortof. since this is lopi they use casing pipe for the stove to go up into the black stove pipe. he tried screwing into that, i mean what’s that 5/16” thick pipe?!
 

rosieXdox

New Member
Sep 29, 2021
70
new jersey
I’m very nervous about the gap where the hot air can get inside the actual chimney, but not inside the terra-cotta because of that huge gap. we plan to open the wall back up and concrete that spot. so that the chimney pipe is only able to put air into the terra-cotta pipe and not into the chimney space
 

begreen

Mooderator
Staff member
Nov 18, 2005
93,751
South Puget Sound, WA
It doesn't look like they did anything to improve clearances to the wood paneling or drywall underneath. A section of double-wall stove pipe is not proper at all for this situation, nor is double-wall insulated (class A) unless proper clearances for it are observed. It should have an insulated thimble from Saf-T-Thimble (heat fab) or Insul Flue (Dalsin Mfg).

Here is an article on passing through a wall. My guess is that the stove manual also has a page or more on this topic.
 
  • Like
Reactions: Shrewboy

rosieXdox

New Member
Sep 29, 2021
70
new jersey
The lopi Endeavor manual had a lot about chimneys. but not a lot about specific wall pass through.


I went to pay for the stove and talk to the main guy there today. Initially when i told him my understanding of what happened he was very upset and would t allow me to pay. He wanted the other main guy to go and look at it here.
then I showed him the picture with the silver double wall chimney pipe and he said ok that IS class A thimble. I said ok, i thought it was double wall chimney pipe. I thought i needed that big bubble thing.

right now, it’s the pipe inside what your link calls a crock, and then outside of that is something white. Idk if it’s durock, sheet rock, i don’t know. it’s under the wood paneling.


your link is what they said initially that i’d need. they initially said way back when i was just looking at stoves. They said i’d need a whole wall of brick of something. And have to be rid of the pine wall paneling. Then they came to the realization that class a thimbles exist- like they just suddenly remembered or came up with that idea.
so after being charged for one at nearly 300...... i don’t think that’s what i’ve got? or is class a thimble the same thing as bounce wall chimney pipe? or is it triple walled and i just don’t know what’s what?

the guy said it needed 2” from the outside of the pipe to the nearest combustible, and measures that area even if the crock is part of the space that’s being measured.
your article said it needed to be 2” empty airspace. and that’s not what’s here.
 

begreen

Mooderator
Staff member
Nov 18, 2005
93,751
South Puget Sound, WA
the guy said it needed 2” from the outside of the pipe to the nearest combustible, and measures that area even if the crock is part of the space that’s being measured.
your article said it needed to be 2” empty airspace. and that’s not what’s here.
It's hard to tell from the photo what they used. Just guessing here but maybe they cut back the outer skin and used the inner liner as a snout into the actual chimney? If they used class A chimney pipe there then 2" clearance to any combustible is a requirement. There are class A thimbles that maintain this gap including the one the manufacturer of the chimney pipe.
 

rosieXdox

New Member
Sep 29, 2021
70
new jersey
It's hard to tell from the photo what they used. Just guessing here but maybe they cut back the outer skin and used the inner liner as a snout into the actual chimney? If they used class A chimney pipe there then 2" clearance to any combustible is a requirement. There are class A thimbles that maintain this gap including the one the manufacturer of the chimney pipe.
are we talking 2”
of empty airspace from outside edge of the pipe? it’s sitting inside the crock. is it 2” away from things that could catch, meaning it can touch the crock? and the crock can touch the white (unsure if that’s durock, sheet rock, or something else)?
 

rosieXdox

New Member
Sep 29, 2021
70
new jersey
When they cut it- they cut through it flat. they didn’t only cut 1 layer. it’s just cut to shorten it to the right length to fit into the wall hole depth.

there’s 3 pieces-
1 -is the class a pipe (thimble)?
2- is the flare
3- is the ring
4- is the stove pipe to elbow
5- is the wlbow
6- is the stove pipe into the stove.

i asked about not having the stove pipe adapter with the crimps bit and he said with these newer stoves you just put stove pipe (ours is double wall telescoping) directly over the stove.
 

begreen

Mooderator
Staff member
Nov 18, 2005
93,751
South Puget Sound, WA
By cutting it, they violated the UL certification for the pipe. And a flush connection against the chimney brick face means a leaky seal and a potential spot for a hot spark to get in the wall. And the only thing supporting the class A that they used is the surrounding wood and drywall which it needs to be 2" away from. This is amateur hour.

It would have been much better off by using an uncut, 6" or 12" section of class A, with a short sleeve of stainless 6" single wall to penetrate to the inner wall of the chimney, with the class A run through a class A thimble.

An even better install would have a full, insulated liner run down the chimney to a liner tee, capped on the bottom (, unless there is a cleanout door at the bottom of the chimney). The tee snout would be run through a proper, insulated wall thimble of the type mentioned above.
 

rosieXdox

New Member
Sep 29, 2021
70
new jersey
By cutting it, they violated the UL certification for the pipe. And a flush connection against the chimney brick face means a leaky seal and a potential spot for a hot spark to get in the wall. And the only thing supporting the class A that they used is the surrounding wood and drywall which it needs to be 2" away from. This is amateur hour.

It would have been much better off by using an uncut, 6" or 12" section of class A, with a short sleeve of stainless 6" single wall to penetrate to the inner wall of the chimney, with the class A run through a class A thimble.

An even better install would have a full, insulated liner run down the chimney to a liner tee, capped on the bottom (, unless there is a cleanout door at the bottom of the chimney). The tee snout would be run through a proper, insulated wall thimble of the type mentioned above.
They’re coming back tuesday to fix the gap.
what can i say to ask them to do it right, without removing the entire wall area? they had originally planned to cut back the pine some, but that isn’t what happened.

i’m just an average joe, all of this is a language i’m learning.
what can I say so that they do it right?
Shouldn’t they be measuring for clearances too? they didn’t measure anything.
we did measure after the guys left and it’s ok except it’s too close by a bout an inch.

so best option if money and time weren’t factors would be - reline the chimney with double wall chimney pipe. The brick of the chimney does have a clean out. So i guess the T pipe with the clean out cap might just be a straight pipe or a T to the clean-out? unsure how you’d terminate the pipe. but i’m sure that’s not a new thing.

your one article said over 80% of homes it’s wrong. well this one is
 

d.sebens

Member
Oct 26, 2021
89
White Heath Illinois
If you keep getting push back for them to do it right you could call the stove manufacturer and see if you can talk to the regional rep. It’s easy to screw a person but they might listen more if their fireplace/stove brand is upset with them.
 

rosieXdox

New Member
Sep 29, 2021
70
new jersey
So i understand that they need to re do the through wall?
and ideally the metal chimney pipe should fit into and past the threshold of the terra-cotta chimney pipe? then should the space between the sides of the pipe and the terra-cotta pipe be filled with masonry?
right now the pipe they cut ends at the end of the crock. and the gap exists where the corner edge of the terra-cotta pipe. so you can see around the outside of the terra-cotta pipe and see the brick masonry chimney interior.
 

rosieXdox

New Member
Sep 29, 2021
70
new jersey
If you keep getting push back for them to do it right you could call the stove manufacturer and see if you can talk to the regional rep. It’s easy to screw a person but they might listen more if their fireplace/stove brand is upset with them.


I really don’t like getting people in hot water.
this is my home, and the lives of my family, if there’s a house fire. idk.

i might call a different local company if when this other guy from this company comes on tuesday tells me it’s all square, even when I ask begreens questions.
 

begreen

Mooderator
Staff member
Nov 18, 2005
93,751
South Puget Sound, WA
I've explained 2 options for a better install. @bholler may have additional ideas. Regardless of the method there will be some cutting back of the combustibles to achieve the required clearance. How much will depend on the method used.
 
  • Like
Reactions: rosieXdox

panderson03

Member
Oct 21, 2018
33
minnesota
The 1/2” gap can easily be filled with a board cut to the height oh the hearth pad.. There should be no carpet under the hearth. If it were me and I wanted a custom fit, I would just make one with a bottom plywood layer, then cement board then tile.
that's what we did for our 3 hearths
 

rosieXdox

New Member
Sep 29, 2021
70
new jersey
i have updates.

today a guy came who looked at it. He didn’t want to take out the pipe inside the crock. he didn’t have any concrete with him, so idk why he came, he said he’s been sent to the wrong calls all week. I said they told me “Lou” was supposed to come and as soon as i said that he said I’ll just leave it like this and i’m sure he’s coming. Lou is the owner.

No one else came.

I’ve taken some more pictures.
I also called a different shop and asked questions.
That shop told me Class A pipe is not supposed to be cut. And there should be no holes or gaps. It should be a closed pipe, one exit one entry point. But he did not want to come into this and help fix. He said he doesn’t know what’s going on, and doesn’t get in the middle of another places work. And he couldn’t speculate on whether is is actually right, or wrong. But that class A shouldn’t be cut, and the path from the wood stove to the top of the chimney should be a closed pipe, no holes, no gaps.


Since the terra-cotta chimney liner/flue has a gap where you can see around it, should the whole terra-cotta pipe be removed and a steel liner installed?
Should it be repaired with cement?
Should the class A pipe be replaced with a not cut piece?
Should the class A pipe fit into the terra-cotta pipe interior? Or butt up against the exterior of the terra-cotta? or be close to the exterior of the terra-cotta but not close enough to touch?

The 2” clearance is another one I’m not clear on. Please forgive me. I just want to figure this out so I know what’s going on, and I know if we are up to code and most importantly safe.