Chimney Liner Quandry

[Cincygoof]

I have a wood burning fireplace.
I was recently advised that due to the amount of creosote glazing at the top of my chimney, the best option is to have a steel liner inserted. I have gotten multiple estimates; however, one thing that has me puzzled is that some say that the original clay liner needs to be removed before placing the new liner, but others say it can be done without removing the original clay tiles. Of course the option which does not remove the old tiles is significantly cheaper.
My question is to those who know better than me: is there really a significant difference or benefit to removing the old clay liner as opposed to just inserting inside the current liner? In both circumstances we have been told that there is a lifetime warranty on the new liner.

 

[bholler]

I have a wood burning fireplace.
I was recently advised that due to the amount of creosote glazing at the top of my chimney, the best option is to have a steel liner inserted. I have gotten multiple estimates; however, one thing that has me puzzled is that some say that the original clay liner needs to be removed before placing the new liner, but others say it can be done without removing the original clay tiles. Of course the option which does not remove the old tiles is significantly cheaper.
My question is to those who know better than me: is there really a significant difference or benefit to removing the old clay liner as opposed to just inserting inside the current liner? In both circumstances we have been told that there is a lifetime warranty on the new liner.

We need allot more info to answer that question. What size is the fireplace opening?
What size is your current liner?
Is the current liner straight with no offset joints?
Does the chimney have the required clearances to combustibles?
Can the existing creosote be cleaned properly so a new liner can be installed.

 

[stoveliker]

Welcome to the forum. You came to the right place. (And the first response is by THE (professional) chimney expert here. So heed his advice.)

To give some context to the questions above: the flue should be the same cross sectional size as the exhaust opening of the fireplace - i.e. it's not good to make the flue smaller than the fireplace needs, because then you may get smoke roll out in your room.

If the clay tiles are the exact size the fireplace needs, then adding a liner inside will always make the cross section smaller. While there is (can be) some range of play in which the system will still work properly, it may not be the case here.

Second, if clearances from the outside of the masonry chimney to combustibles are not met, you need an insulated liner. For fire safety (and to meet code). That insulation takes additional space around the steel liner.

(And liners should only be installed in a clean(ed) chimney, to avoid having the creosote get hot in pockets after the liner is in.)

My main question is: is this indeed a (masonry) fireplace, or something else? Can you post a pic of the fireplace, and as much of the chimney as you can photograph (top, and if outside, the whole thing). These things will help getting the best advice.

 

[Cincygoof]

I'm not sure of some of the questions posed, such as size of my existing liner.
The company who is proposing to add a liner without removing the existing clay liner believes the creosote can adequately be cleaned. Of course the company who wants to remove the liner has said that chemical treatment to clean doesn't actually work efficiently.
I have attached a couple of photos this time. The opening of my fireplace is 36"x 29" (it's 26" deep, but don't know if that is pertinent). I'm not sure of the combustible to clearance ratio, or how to measure/estimate this.
I do not believe there are any real issues with the current liner, other than creosote glazing. The inspection didn't show any vertical cracks or major gaps or offset joints.
If the liner is removed, an 11" insulated liner would be installed; if not removed, the company proposes a 9"insulated liner.

 

[stoveliker]

It is hard to see, but I think there are shingles within an inch of the masonry chimney. That would necessitate an insulated liner.

I know nothing of chemical cleaning of creosote.

 

[Cincygoof]

We need allot more info to answer that question. What size is the fireplace opening?
What size is your current liner?
Is the current liner straight with no offset joints?
Does the chimney have the required clearances to combustibles?
Can the existing creosote be cleaned properly so a new liner can be installed.

I made a new posting with pictures and the information, I hope, will offer additional insight into the situation.

 

[bholler]

I made a new posting with pictures and the information, I hope, will offer additional insight into the situation.

For proper sizing you need 104 square inches of liner. Even 11" is slightly small but it should work. 9" probably wont

 

[Cincygoof]

It is hard to see, but I think there are shingles within an inch of the masonry chimney. That would necessitate an insulated liner.

I know nothing of chemical cleaning of creosote.

There is several inches (maybe 3-4) of metal flashing between the chimney and the shingles. Both options presented for the liners are insulated, but different sizes depending on whether the existing clay liner tiles are removed or not

 

[Cincygoof]

For proper sizing you need 104 square inches of liner. Even 11" is slightly small but it should work. 9" probably wont

Thank you.

 

[Cincygoof]

We have continued to get estimates for work on our chimney. A third option has been presented and I was hoping to get professional opinions on this. It is the option of cleaning the existing clay liner and applying a coating to the liner to seal the existing liner. Any good or bad experiences with this type of product?

 

[bholler]

We have continued to get estimates for work on our chimney. A third option has been presented and I was hoping to get professional opinions on this. It is the option of cleaning the existing clay liner and applying a coating to the liner to seal the existing liner. Any good or bad experiences with this type of product?

My experience with that product is that it is an expensive relatively short term option

 

[Cincygoof]

Thank you.