Masonry thimble questions

bholler

Chimney sweep
Staff member
Jan 14, 2014
23,037
central pa
The reason I have to change the clean out door is whoever built the chimney put in a fireplace ash door instead of a clean out door. I'll have to pull it and cut it out a little more to put in an actual clean out door. I do appreciate all the responses I've got from everyone. It's helped out a lot. Looks like the sat-t-thimble or the Olympia wall thimble are two options I'm going to look at for this. I'm gonna look into them both some more and see when I can have the chimney sweep come out. When I called the ther day it would be into December before he could make it out. So once he comes to check the chimney for safety I'll ask him about my plan. I'll be having them come back out after I do the install to do an installation inspection for insurance and make sure everything is good.
Yeah change that out for sure no way it will seal right. I really prefer the olympia one the safe-t-thimble works fine the olympia one is just much easier to install
 

Nadroj

New Member
Nov 23, 2016
17
Ohio
With the Olympia thimble do I need to buy the rigid pipe seperatly from the thimble or does the thimble have everything needed and once I install it I just connect my stove pipe from stove into the Olympia thimble?
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
23,037
central pa
With the Olympia thimble do I need to buy the rigid pipe seperatly from the thimble or does the thimble have everything needed and once I install it I just connect my stove pipe from stove into the Olympia thimble?
Get the one for the masonry chimney for your application as long as the sweep says your liner is in good shape ect. It will come with a peice of rigid stainless pipe to go through the thimble they also make one for a ss liner that comes with an extended tee snout.
 

Nadroj

New Member
Nov 23, 2016
17
Ohio
Thanks b holler, looks like next step will probably be setting a date for the sweep to inspect the chimney and liner!
 

Nadroj

New Member
Nov 23, 2016
17
Ohio
Had a certified sweep come out and do an inspection on the chimney. He said the chimney never appeared to be used much but did say he saw a couple hair like cracks in the liner in a couple spots probably from moisture and cold weather so he deemed it unusable. Looks like my options are to line it or rebuild it. Or I could change plans with it and just go with class a stainless.

They are supposed to give me a quote on lining it but it's gonna be way to expensive for them to do it I know. He was saying roughly $1500 to $2000 probably.
 

Ashful

Minister of Fire
Mar 7, 2012
15,715
Philadelphia
My stainless liners have cost:

$1800 = 45 feet rigid un-insulated in 1998
$1600 = 20 feet flex un-insulated in 2011
$3000 = 29 feet + 15 feet (two chimneys) smooth-wall flex with insulation in 2014

The 29 foot chimney had some serious complications.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
23,037
central pa
$1800 = 45 feet rigid un-insulated in 1998
$1600 = 20 feet flex un-insulated in 2011
$3000 = 29 feet + 15 feet (two chimneys) smooth-wall flex with insulation in 2014
they should all be insulated so that will push those prices up a bit.
 

Ashful

Minister of Fire
Mar 7, 2012
15,715
Philadelphia
The two uninsulated liners were on oil furnaces, not wood stoves. They were also installed in terra cotta lined chimneys, in which the terra cotta liner had failed or shifted.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
23,037
central pa
The two uninsulated liners were on oil furnaces, not wood stoves. They were also installed in terra cotta lined chimneys, in which the terra cotta liner had failed or shifted.
Ahh ok we still insulate but it is not required. It still reduces condensation and stabilizes draft so we do it.
 
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Nadroj

New Member
Nov 23, 2016
17
Ohio
If my flue roughly measures 7x 7 1/4 when measure the I.D at the top of my chimney will a 6" line fit in that? I'm assuming I would have to insuate a stainless liner and I would think a 6" liner with insulation would be a snug fit if even possible?
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
23,037
central pa
If my flue roughly measures 7x 7 1/4 when measure the I.D at the top of my chimney will a 6" line fit in that? I'm assuming I would have to insuate a stainless liner and I would think a 6" liner with insulation would be a snug fit if even possible?
Yeah I can all but guarantee it is not going to fit without taking the tiles out.
 

Nadroj

New Member
Nov 23, 2016
17
Ohio
What I was figuring. I haven't heard back from the sweep as far as an estimate goes and what all there plan was to do a liner but I didnt think a 6" would fit with the clay liner. Any liners out there allow a type of insulation like vermiculite to be poured around it instead of a blanket type of insulation?

Bholler, I appreciate all the responses I've got from you, it really helps me out a lot! Thank you
 
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Ashful

Minister of Fire
Mar 7, 2012
15,715
Philadelphia
Yeah I can all but guarantee it is not going to fit without taking the tiles out.
I assume you mean insulated? Wouldn't an uninsulated flex liner fit? Cap with block of plates, and fill with vermiculite, if you please.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
23,037
central pa
I assume you mean insulated?
Correct. But many times even a bare liner wont fit. It does not take mutch of an offset in a joint to cause a big problem.

Cap with block of plates, and fill with vermiculite, if you please.
No way to get enough pour in there to meet code requirements. You need 1" of insulation all the way around and you cant get that there.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
23,037
central pa
. Any liners out there allow a type of insulation like vermiculite to be poured around it instead of a blanket type of insulation?
As I said above yes many allow for it but require 1" of insulation for use with solid fuel. And you cant get that.
 

Ashful

Minister of Fire
Mar 7, 2012
15,715
Philadelphia
As I said above yes many allow for it but require 1" of insulation for use with solid fuel. And you cant get that.
bholler, does that vary by state / locale? I do not believe an insulated liner is code, here. Or at least, I can say I've had no less than 7 different outfits quote me an UN-insulated liner in an existing clay tile chimney. It seems, at least around here, they're only recommended for otherwise-seriously compromised chimneys.
 
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bholler

Chimney sweep
Staff member
Jan 14, 2014
23,037
central pa
bholler, does that vary by state / locale? I do not believe an insulated liner is code, here. Or at least, I can say I've had no less than 7 different outfits quote me an UN-insulated liner in an existing clay tile chimney. It seems, at least around here, they're only recommended for otherwise-seriously compromised chimneys.
Well no an insulated liner is not absolutely required in every situation. But for a solid fuel burning appliance unless you have the required clearance to combustibles from the outside of the masonry structure you need a fully insulated liner. That means for an external chimney 1" space between the chimney and any combustibles and 2" for any interior chimney. I have been doing this a long time and have seen very few chimneys that actually met that requirement. And best practices tell sweeps that unless you can positively confirm the required clearances the entire length of the chimney you need to assume those clearances are not met. The condition of the chimney has absolutely no bearing on the requirement for insulation at all. So yes there are allot of guys out there who drop uninsulated liner but that does not mean it is right many of them also don't thoroughly clean the chimney before hand either or do the full level 2 inspection to check for clearances ect.

In addition to that by code you are required to install a ul listed component in accordance with its listing. And every manufacturer I have talked to about it says that their liner was only tested for solid fuel with insulation on it. So to me insulation is required for that reason as well.

For oil and gas it is not required in any cases but is recommended.
 
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Ashful

Minister of Fire
Mar 7, 2012
15,715
Philadelphia
Thank you, bholler. Always a wealth of information!
 
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Nadroj

New Member
Nov 23, 2016
17
Ohio
Well, been a while and no update. I had debated whether to tear the block chimney down and replace with class a or take a hand at knocking out the clay liner to put in insulated stainless flex liner. I put together a tool yesterday and put it to work this evening and got most of the liner knocked out and will finish tomorrow hopefully. If all goes well I'll add another chimney block to the top to meet the code requirement for the height and order a stainless flex liner kit with insulation and the Olympia insulated masonry thimble. I think I may veneer stone the block as well later this fall if time and finances allow.
 

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funbaker10

New Member
Oct 28, 2019
4
Wisconsin
Nadroj, this was a great post with many good questions, answers, and discussions. How did the project end up working out for you?

bholler, a few posts back you mentioned the for an interior masonry chimney there must be 2" of clearance from the outside of the masonry structure to any combustibles. Is this clearance gap meant to have high temperature capable insulation stuffed into this 2" gap? If not, wouldn't this clearance create a "hole" per say from the inside of the house to the outside? How would warm air from the house be prevented from following the chimney right through the roof?
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
23,037
central pa
Nadroj, this was a great post with many good questions, answers, and discussions. How did the project end up working out for you?

bholler, a few posts back you mentioned the for an interior masonry chimney there must be 2" of clearance from the outside of the masonry structure to any combustibles. Is this clearance gap meant to have high temperature capable insulation stuffed into this 2" gap? If not, wouldn't this clearance create a "hole" per say from the inside of the house to the outside? How would warm air from the house be prevented from following the chimney right through the roof?
You can close the hole with non-combustible materials