Chimney Liner Clearence Question

[pberardi]

Hope I put this in the right forum. Looking to see if i am ok with clearances in the attached pictures.

I installed a 316ti liner through an existing internal chimney yesterday and want to make sure my installation is safe and I am interpreting the code correctly. The previous owner had a wood burner on the first floor and would use that as a primary heat source. I removed the floor in that room for a staircase opening and purchased a new liner in hopes of moving the wood stove to the basement.

I tried to draw out my chimney to better depict my setup.

Picture 1 - I removed the floor and put in 2x12's to support the chimney from the first floor since the brick did not run from the basement to the first floor. There is about a 1/2"-3/4" gap between the wood 2x12's and the block chimney liner. Some of the wood shims I used are touching the block.

Picture 2 - I think this is fine since I removed the wall that was present when I moved in and just rebuilt it and made it smaller. This wall does have 2x4's in it however they are not touching the chimney liner.

Picture 3 - I have about 6.5" of clearance from my tee stub out to the 2x4 on the right. I will be framing the wall with steel studs and using a wall thimble to go through the drywall. My concern is the floor joist shown with the arrow - there is only about 3/4" of clearance here.

 

[bholler]

Hope I put this in the right forum. Looking to see if i am ok with clearances in the attached pictures.

I installed a 316ti liner through an existing internal chimney yesterday and want to make sure my installation is safe and I am interpreting the code correctly. The previous owner had a wood burner on the first floor and would use that as a primary heat source. I removed the floor in that room for a staircase opening and purchased a new liner in hopes of moving the wood stove to the basement.

I tried to draw out my chimney to better depict my setup.

Picture 1 - I removed the floor and put in 2x12's to support the chimney from the first floor since the brick did not run from the basement to the first floor. There is about a 1/2"-3/4" gap between the wood 2x12's and the block chimney liner. Some of the wood shims I used are touching the block.

Picture 2 - I think this is fine since I removed the wall that was present when I moved in and just rebuilt it and made it smaller. This wall does have 2x4's in it however they are not touching the chimney liner.

Picture 3 - I have about 6.5" of clearance from my tee stub out to the 2x4 on the right. I will be framing the wall with steel studs and using a wall thimble to go through the drywall. My concern is the floor joist shown with the arrow - there is only about 3/4" of clearance here.

You absolutely need an insulated liner. For an internal chimney like yours you need 2" of clearance to combustibles. You also have wood way too close to the pipe as it exits the chimney.

 

[pberardi]

If that is the case i will need to switch gears and move the appliance to the first floor since cutting the floor back is not an option

 

[begreen]

There is wood too close to the chimney in many locations, not just the floor. An insulated liner is definitely necessary.

Curious about why were 2x12s used instead of brick?

 

[bholler]

If that is the case i will need to switch gears and move the appliance to the first floor since cutting the floor back is not an option

Chances are you need an insulated liner regardless

 

[pberardi]

The 2x12's were actually there from before, i just cut the floor out and cut them short since i needed to hold up the brick in the top half shown in the pictures. The previous owner must have burned in the basement at one point since the original chimney liner is dirty.

I could figure out how to cut the floor back in the picture shown with the tee stub. I am not sure how to fix the brick issue though...i guess i could fab up some steel but that would be a pretty big task.

 

[pberardi]

Would something like this be an option?

(broken link removed to http://duravent.com/docs/product/DuraLiner_Catalog.pdf)

Says its 0 clearance?

 

[bholler]

Would something like this be an option?

(broken link removed to http://duravent.com/docs/product/DuraLiner_Catalog.pdf)

Says its 0 clearance?

To replace the liner you just put in yes. But you could also just pull it remove the clay tiles and insulate the liner you have. Dura liner will nor address the clearances of the pipe after it leaves the chimney. You will need an insulated thimble and possibly doublewall pipe.

 

[pberardi]

I am on board with getting an insulated wall thimble to be safe i am going to replace the two 2x4's next to the tee stub with steel studs also. I could probably get 1/4" insulation around it as it is now in the clay liner. Is that enough? I read a lot before the install and decided to not insulate since it said it was not required since i am going through about 70% conditioned space, thoughts?

I made some progress tonight. Moved the 2x12's out to 2.125" clearance on all three sides and cut the floor back on the one. Sucks but i need to open up the wall i just put in to remove one 2x4, i will do that tomorrow.

What do i do in the attic where it comes through the ceiling? I am going to cut the 2x4 top plate for the wall but i will have a 2" gap that will be a good highway for mice, can i fill it with something?

 

[bholler]

I am on board with getting an insulated wall thimble to be safe i am going to replace the two 2x4's next to the tee stub with steel studs also. I could probably get 1/4" insulation around it as it is now in the clay liner. Is that enough? I read a lot before the install and decided to not insulate since it said it was not required since i am going through about 70% conditioned space, thoughts?

I made some progress tonight. Moved the 2x12's out to 2.125" clearance on all three sides and cut the floor back on the one. Sucks but i need to open up the wall i just put in to remove one 2x4, i will do that tomorrow.

What do i do in the attic where it comes through the ceiling? I am going to cut the 2x4 top plate for the wall but i will have a 2" gap that will be a good highway for mice, can i fill it with something?

It is required because you dont have required clearances. And no 1/4" is not enough. You need 1/2" insulation to reach zero clearance from the outside of the masonry structure.

 

[pberardi]

That would be if i still had combustibles touching the masonry chimney liner though right? With what I did last night and hopefully today I will have corrected the clearance issue and provided a 2" air void on all four sides of the masonry chimney liner. After i pull stuff away tonight my only focus would be on properly existing the chimney in the basement with double wall pipe/timble or insulated thimble.

With all that being said I would be within code if i left the liner as is and if I added insulation it would be icing on the cake?

 

[bholler]

That would be if i still had combustibles touching the masonry chimney liner though right? With what I did last night and hopefully today I will have corrected the clearance issue and provided a 2" air void on all four sides of the masonry chimney liner. After i pull stuff away tonight my only focus would be on properly existing the chimney in the basement with double wall pipe/timble or insulated thimble.

With all that being said I would be within code if i left the liner as is and if I added insulation it would be icing on the cake?

You need that 2" of clearance from the outside of the brick not the liner. And yes if you get that clearance the entire way up it would be safe without insulation.

 

[pberardi]

Now that makes sense. I am very thankful for all the great help.

One more thing - Can i put a 1/4" blanket around the liner and reinstall then put mortar style insulation fill between the clay liner and block? that would give me almost 1" of insulation. I am trying to avoid removing the clay liner for obvious reasons. Honestly if i could get away with just putting the mortar style insulation between the clay liner and block without adding the 1/4" blanket that would be huge.

 

[bholler]

Now that makes sense. I am very thankful for all the great help.

One more thing - Can i put a 1/4" blanket around the liner and reinstall then put mortar style insulation fill between the clay liner and block? that would give me almost 1" of insulation. I am trying to avoid removing the clay liner for obvious reasons. Honestly if i could get away with just putting the mortar style insulation between the clay liner and block without adding the 1/4" blanket that would be huge.

If you have the required clearances and your liner is rated for pour in then yes you could do that.

 

[pberardi]

Bad news from tonight. found some type of adhesive in between the block of the chimney and the brick after i opened up the wall. I used to do a lot of masonry work and this smells just like construction adhesive/block adhesive.

 

[bholler]

Bad news from tonight. found some type of adhesive in between the block of the chimney and the brick after i opened up the wall. I used to do a lot of masonry work and this smells just like construction adhesive/block adhesive.

Yeah that means the clay needs to come out so the liner can be properly insulated.

 

[pberardi]

so even with the glue/adhesive on there it would be safe with 1/2" insulation? I was worried about that stuff melting/burning.

 

[bholler]

so even with the glue/adhesive on there it would be safe with 1/2" insulation? I was worried about that stuff melting/burning.

Yes the half inch insulation gives you zero clearance to combustibles on the outside of that block

 

[pberardi]

Well chimney clay liner is removed. I cut a small sledge hammer head in half, welded it to some chain and a piece of rebar. I ordered 1/2" insulation and a wall thimble for the basement where it comes out of the block liner.

 

[bholler]

Well chimney clay liner is removed. I cut a small sledge hammer head in half, welded it to some chain and a piece of rebar. I ordered 1/2" insulation and a wall thimble for the basement where it comes out of the block liner.

Good for you

 

[black smoke signals]

so even with the glue/adhesive on there it would be safe with 1/2" insulation? I was worried about that stuff melting/burning.

Cool home made tool !!

 

[pberardi]

Well, fedex was expected to show up Thursday and I even took a half day Friday to install the liner. Didn't show, turns out the chimney place never shipped it by mistake. Liner finally got here from fedex today around 11am. Fiance helped me put the insulation on and carry the liner out to the front yard. Got the liner in, put the wall thimble on.

What is the distance to combustibles with that thimble? in the install booklet they show framing out a square around the pipe to help support it so i would assume 0"? The nearest combustible to the thimble is about 8" (2x4 shown in the picture).