Steel liner inside clay liner

[FiveAlive]

Hey all,

Received 2 quotes to install a wood stove. Both were similar in price but one wanted an extra $500 to smash the current clay liner (approx 6.5 inches by 7 inches) and the other one would put the 6inch steel liner inside the current clay liner.

I prefer the latter option but just wanted to make sure it would be safe to do so, the condition of the clay liner seems ok but no doubt the steel liner would touch part of the clay liner when being placed.

I just wanted to ask if this would be a safety concerns or would not cause any issues even if the steel liner would touch the clay liner in some areas

Any thoughts?

 

[bholler]

Hey all,

Received 2 quotes to install a wood stove. Both were similar in price but one wanted an extra $500 to smash the current clay liner (approx 6.5 inches by 7 inches) and the other one would put the 6inch steel liner inside the current clay liner.

I prefer the latter option but just wanted to make sure it would be safe to do so, the condition of the clay liner seems ok but no doubt the steel liner would touch part of the clay liner when being placed.

I just wanted to ask if this would be a safety concerns or would not cause any issues even if the steel liner would touch the clay liner in some areas

Any thoughts?

Are they going to insulate the liner where they are doing the breakout?

 

[Ctwoodtick]

The liner needs to be insulated. If your installers aren’t talking about that get another quote w/ insulation included.

 

[FiveAlive]

I should have stated our chimney is in the middle of the house not exterior. I spoke with the manufacturer and they indicated there was no need to insulate interior chimneys. I’ve attached a photo of what the clay liner looks like.

 

[bholler]

I should have stated our chimney is in the middle of the house not exterior. I spoke with the manufacturer and they indicated there was no need to insulate interior chimneys. I’ve attached a photo of what the clay liner looks like.

What manufacturer? Did they check to see if you had the required 2" clearance to combustibles from the outside of the masonry chimney structure? If they didn't check that they have no clue if you need insulation or not.

 

[Tech Guru]

When I worked for a manufacturer we would always preface that it wasn't required (or as necessary) on a 'code compliant' masonry chimney. Those two words get you out of a world of trouble. But agreed, if you can't be certain your system has maintained the proper clearances when the masonry chimney was built, or any framing that was done afterwards, insulating the liner would always be preferable.

 

[FiveAlive]

Osburn is the manufacturer,

Would the clay liner not act as sufficient protection? Our house is approximately 50 years old, I'm not sure if insulation was needed on the outside of the clay liner in the older times but I imagine there would be some type of protection as it would not have been safe to use wood stoves back then no?

From previous posts on hearth.com and through other resources, nearly all indicated insulation is not needed for interior chimneys but there are always some favoring it, some not.

The chimney that runs through the middle of our house and I believe the only area that may be combustible within 2 inch of the chimney is the hardwood floor on the main level (possibly the ceiling / walls too but I'm not sure). I don't know if the putting a steel liner inside the current clay liner would offer sufficient protection without having to add insulation around the steel liner if this is even something that is needed.

One option to still have some insulation would be the pour in insulation such as Everguard. If it is beneficial to have this between the steel liner & clay liner I can ask the installer for this.

I've also heard Roxul can be stuffed around the liner as well.

I realize there's likely not an answer that is uniform.

Any thoughts on this? Would it be better to add insulation or is it not necessary given the setup I have?

 

[webby3650]

In the event of a chimney fire, if your current chimney doesn’t have proper clearance, the radiant heat from the fire will transfer straight through the chimney. Obviously the results are catastrophic. Very rarely do masonry chimney’s have proper clearance, typically the floor system is attached to chimney...

 

[FiveAlive]

Alright thanks,

In that case, we may just go with another option with from a different quote using a 5 inch or 5.5 inch liner (this was with a Pacific Energy wood stove) . They did indicate that they would put roxul insulation around the liner.

While sub 6 inch liner is not recommended through Osburn, they stated it can be done. The dealer for the Pacific Energy mentioned that the Super 27 stoves function just as well with 5 inch liners.

The documentation of the super 27 just mentions a 6 inch liner. Will using a smaller liner than 6inch have any adverse effects?

 

[bholler]

Alright thanks,

In that case, we may just go with another option with from a different quote using a 5 inch or 5.5 inch liner (this was with a Pacific Energy wood stove) . They did indicate that they would put roxul insulation around the liner.

While sub 6 inch liner is not recommended through Osburn, they stated it can be done. The dealer for the Pacific Energy mentioned that the Super 27 stoves function just as well with 5 inch liners.

The documentation of the super 27 just mentions a 6 inch liner. Will using a smaller liner than 6inch have any adverse effects?

If they are breaking out the liners you will have plenty of room for insulation. Without removing the tiles even with a 5.5 you won't have room to insulate properly.

 

[FiveAlive]

Thanks bholler,

I think the simplest solution is just to tear down the clay liner and put a properly sized 6 inch chimney liner and insulating it appropriately instead of down sizing it with insufficient insulation.

Would Roxul insullation be sufficient as insulation? That's what the dealer for the Pacific Energy uses.

 

[bholler]

Thanks bholler,

I think the simplest solution is just to tear down the clay liner and put a properly sized 6 inch chimney liner and insulating it appropriately instead of down sizing it with insufficient insulation.

Would Roxul insullation be sufficient as insulation? That's what the dealer for the Pacific Energy uses.

No roxul is not an approved chimney liner insulation. And I don't know how you would go about installing it anyway. You need a ul listed chimney liner insulation or a pre insulated liner

 

[webby3650]

Roxul is commonly used to stuff around the liner at the top and above the block off plate at the bottom. Either they are incorrectly calling the liner insulation Roxul, or they are considering “insulated” only stuffed around the liner at the top. It would not be possible to insulate a liner with Roxul.