I have a 1"x5" hole at the rear of my smoke ledge, some holes around the throat and the 4"x6" hole I cut in my metal backing of my masonry fireplace; can I patch with ss mesh and refractory cement or is sheet metal and screws better? The smoke ledge hole is barely accesable. I'm preparing to reline.
what's the best patching method for throat and smoke ledge holes prior to reline?
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webbie
Seasoned Moderator
Metal backing? Damper Area? Is this a heatform (metal interior in masonry fireplace) or all masonry with just a cast damper area and frame?
Sheet metal and screws sounds good to me from afar. That has less tendency to crack and fall out. Hopefully the holes are just through one layer and not exposing wood framing, etc.
Maybe some rockwool stuffed in before the metal if you are worried about radiant heat /
Sheet metal and screws sounds good to me from afar. That has less tendency to crack and fall out. Hopefully the holes are just through one layer and not exposing wood framing, etc.
Maybe some rockwool stuffed in before the metal if you are worried about radiant heat /
Craig I think it time to detail a proper inspection of the chimney and firebox, before an insert is installed.
This is covered in code stating a code compliant NFPA 211 fireplace and chimney is require prior to the insert installation
So here goes how to inspect a masonry firebox and chimney. Tools needed a decent flashlight and a hammer.
the chimney set up that brick facing consist only part way up the wall with the top pare having a combustible wall above
Not as big an issue in full-faced floor to ceiling masonry facing
Unfortunately all to often, the masonry brick or facing is not sealed off. With your flash light, from inside the firebox, shine towards the front.
Many times you should see a metal angle iron called a lintel is there a space between the front brick or masonry and the angle iron?
If there is then chances are it is a direct path to the combustible header and framing material above.
The easiest way to fill the gap is to apply refractory cement with a caulking gun, forcing in as much cement in that crack as possible.
Now examine your existing firebricks looking for cracks.
Next lightly tap your firebricks start at the bottom and work to the to. If filled with the required solid masonry the taping sound should be consistent.
If you hear the hollow sound as you work towards the top you just discovered the prior mason took a short cut and the firebox is not NFPA 211 compliant.
There are probably leaves an all sorts of combustibles in there possibly construction debris including blocks of wood. Time to fish your shop vac in there and clean it out.
Now what to do? The easiest suggestion is to fill that area with non combustibles It is almost impossible to get mortar in there but, I would fill it with sand.
Also check the side’s, Damper plates are held in position with cotter pins. It is easier to take the damper plate out to fill in the voids
With the damper plate open or removed, it is time to inspect your chimney Shine the flash light up your chimney look for creosote and look at you clay liners.
Do they line up? do you see missing mortar in the joints? Do you see any cracks or missing or flaking clay liners?
Also note the size of your liner. This will determine whether you need to fully line the chimney to satisfy the cross-sectional area code..
Ok the inside the firebox inspection is done. Time now to head up to the top of the chimney to examine the chimney crown cap and look at your flue liner top down
First thing to look for is the bricks are they intact? Is mortar missing in the joints? Are the top layers cracked or loose? Is the crown cap solid no cracks present? Finally examine your clay liners do you see creosote missing mortar joints or cracks.
As an inspector, I usually require a condition report on all chimneys older than 10 years prior to issuing a permit. Part of that report tells me whether a cleaning is also required.
This is covered in code stating a code compliant NFPA 211 fireplace and chimney is require prior to the insert installation
So here goes how to inspect a masonry firebox and chimney. Tools needed a decent flashlight and a hammer.
the chimney set up that brick facing consist only part way up the wall with the top pare having a combustible wall above
Not as big an issue in full-faced floor to ceiling masonry facing
Unfortunately all to often, the masonry brick or facing is not sealed off. With your flash light, from inside the firebox, shine towards the front.
Many times you should see a metal angle iron called a lintel is there a space between the front brick or masonry and the angle iron?
If there is then chances are it is a direct path to the combustible header and framing material above.
The easiest way to fill the gap is to apply refractory cement with a caulking gun, forcing in as much cement in that crack as possible.
Now examine your existing firebricks looking for cracks.
Next lightly tap your firebricks start at the bottom and work to the to. If filled with the required solid masonry the taping sound should be consistent.
If you hear the hollow sound as you work towards the top you just discovered the prior mason took a short cut and the firebox is not NFPA 211 compliant.
There are probably leaves an all sorts of combustibles in there possibly construction debris including blocks of wood. Time to fish your shop vac in there and clean it out.
Now what to do? The easiest suggestion is to fill that area with non combustibles It is almost impossible to get mortar in there but, I would fill it with sand.
Also check the side’s, Damper plates are held in position with cotter pins. It is easier to take the damper plate out to fill in the voids
With the damper plate open or removed, it is time to inspect your chimney Shine the flash light up your chimney look for creosote and look at you clay liners.
Do they line up? do you see missing mortar in the joints? Do you see any cracks or missing or flaking clay liners?
Also note the size of your liner. This will determine whether you need to fully line the chimney to satisfy the cross-sectional area code..
Ok the inside the firebox inspection is done. Time now to head up to the top of the chimney to examine the chimney crown cap and look at your flue liner top down
First thing to look for is the bricks are they intact? Is mortar missing in the joints? Are the top layers cracked or loose? Is the crown cap solid no cracks present? Finally examine your clay liners do you see creosote missing mortar joints or cracks.
As an inspector, I usually require a condition report on all chimneys older than 10 years prior to issuing a permit. Part of that report tells me whether a cleaning is also required.
webbie
Seasoned Moderator
Good info, Elk....
Attention writers - if anyone wants to take a stab at editing and completing Elks post, it would make a great wiki entry! We could also add a diagram of the firebox with call-outs. I will do the pics and posting if anyone else wants to attempt the writing.
Attention writers - if anyone wants to take a stab at editing and completing Elks post, it would make a great wiki entry! We could also add a diagram of the firebox with call-outs. I will do the pics and posting if anyone else wants to attempt the writing.
Gooserider
Mod Emeritus
I could take a swing at it if you and Elk are willing to work with me on it.... Could take a few days but not that long. I used to do tech writing at my old job, writing and maintaining test procedures - Elk's writing isn't any worse than some of the ESL folks that I had to figure out. 
The boss used to tell me I was one of his best at doing documentation.
Probably would help if I had the firebox diagram to work with so that we are using the same terms for everything.
Gooserider
The boss used to tell me I was one of his best at doing documentation.Probably would help if I had the firebox diagram to work with so that we are using the same terms for everything.
Gooserider
Thanks goose I am thinking of bringing my digital camera along for inspections to show the headers in relatinship to the bricks and shoot som pictures of fireboxes
I then thought I should include the code wording for the need of inspection and try to bring it all together
I then thought I should include the code wording for the need of inspection and try to bring it all together
webbie
Seasoned Moderator
Gooserider
Mod Emeritus
Here's my first pass at Elk's post, with some additional stuff that I thought made it a bit more complete. Please look it over for accuracy, grammar and all that stuff. See if it makes sense as a procedure. Note that I felt there were some places where it would be appropriate to put in either more information or a reference to a different article. I marked those spots with comments in curly braces "{}" - they will need attention.
Gooserider
Instructions on how to inspect a chimney and firebox prior to installing an insert.
This is based on a message from Elk, translated from the Elkish to English by Gooserider. It is not a complete code section, but rather is based on the things that Elk looks at when he goes to inspect a fireplace as part of his job doing inspections for his town's building department.
Per code, any fireplace that an insert is installed in MUST be NFPA 211 Code compliant. In other words, before an insert is installed, it must be verified that the fireplace the insert is going to be put in is structurally sound and safe. (It doesn't mean the fireplace needs to work well, just that it is safe) An insert generates a considerable amount of heat, which must be contained by the fireplace structure to keep it from reaching any combustible parts of the house.
By itself, AN INSERT IS NOT THE CURE FOR AN UNSAFE FIREPLACE! If the fireplace would not be safe to build a fire in, it is not safe to put an insert in, but must be fixed first.
This procedure is also largely applicable if installing a woodstove into, or in front of, a fireplace.
Note that this process is intended for masonry fireplaces with clay tile flues, if you have a "Zero Clearance" (ZC) or other metal fireplace, and / or a chimney made with something other than clay tile liners, please see {reference} or ask for more advice in the forums.
Elk says that as an inspector, he usually requires a condition report on all chimneys more than 10 years old prior to issuing a permit. Part of the report says whether a cleaning is required. {Does this report need to come from a sweep? Should they get this report before or after doing the stuff in this procedure?}
Tools required:
Good flashlight, trouble light, or other strong light source.
Hammer
Wire brushes, scrapers and other implements of destruction (optional depending on how much soot is covering things)
Eye protection and a dust mask or other breathing protection reccomended
Caulking gun with refractory cement (if needed)
Shop vacuum - This can be a very messy job, it helps to keep cleaning up the crud as you work.
Ladder(s) or other way to access top of chimney
1. The first check is mostly needed on fireplaces with a brick facing that only goes part way up the wall, with a combustible wall above. It is less likely to be a problem in full-faced floor to ceiling masonry faced fireplaces, but should be checked in any case. Unfortunately all to often, the masonry brick or facing is not sealed off properly. With your flash light, from inside the firebox, shine towards the front. Many times you will see a metal angle iron called a lintel, that supports the front edge of the fireplace opening. Look for a space between the front brick or masonry facing and the angle iron. There should NOT be any gaps! If there are, then chances are it is a direct path to the combustible header and framing material above. The easiest way to fill a gap is to apply refractory cement with a caulking gun, forcing as much cement into the space as possible.
2. Remove the damper plate. They are usually held in with cotter pins. Removing the damper plate makes the inspection and repair easier, and most insert installs will require that the plate be removed in any case.
3. Examine the existing firebricks in the entire firebox looking for cracks in either the bricks themselves or in the mortar joints between them. Any cracks must be repaired before the insert is installed {need instructions on how....}
4. Lightly tap the firebricks starting at the bottom and working to the top. Do this on both the back and each side. If filled with the required solid masonry the tapping sound should be "solid" and consistent. If you hear a hollow sound, especially as you work towards the top, you just discovered the prior mason took a short cut and the firebox is not NFPA 211 compliant. There may be leaves and all sorts of other combustibles in there, possibly construction debris, including blocks of wood. Time to fish your shop vac in there and clean it out. {How do you get into the space? Remove bricks? Go through the wall on the other side???} The area then needs to be filled with non combustibles. It is almost impossible to get mortar into the space, but filling it with sand is acceptable. {Would it be better to fill it with DRY concrete or mortar mix like "Sakrete" or equivalent, then drop some water on it? It seems like that would be better as the stuff would harden into masonry rather than possibly leak out at some time in the future}
5. With the damper plate open or removed, it is time to inspect the chimney. Shine the light up your chimney, look for creosote (which will need to be cleaned off). Look at your clay liners. Do they line up? Do you see missing mortar in the joints? Do you see any cracks or missing or flaking clay liners? {what do you do if there is a problem?} {Reference on what to do if not clay lined? If you don't have clay liners, further inspection and work will definitely be needed} Also note the size of the liner. This will determine whether you need to fully line the chimney to satisfy the cross-sectional area code. {Insert reference to this!}
(will continue in next post)
Gooserider
Instructions on how to inspect a chimney and firebox prior to installing an insert.
This is based on a message from Elk, translated from the Elkish
to English by Gooserider. It is not a complete code section, but rather is based on the things that Elk looks at when he goes to inspect a fireplace as part of his job doing inspections for his town's building department.Per code, any fireplace that an insert is installed in MUST be NFPA 211 Code compliant. In other words, before an insert is installed, it must be verified that the fireplace the insert is going to be put in is structurally sound and safe. (It doesn't mean the fireplace needs to work well, just that it is safe) An insert generates a considerable amount of heat, which must be contained by the fireplace structure to keep it from reaching any combustible parts of the house.
By itself, AN INSERT IS NOT THE CURE FOR AN UNSAFE FIREPLACE! If the fireplace would not be safe to build a fire in, it is not safe to put an insert in, but must be fixed first.
This procedure is also largely applicable if installing a woodstove into, or in front of, a fireplace.
Note that this process is intended for masonry fireplaces with clay tile flues, if you have a "Zero Clearance" (ZC) or other metal fireplace, and / or a chimney made with something other than clay tile liners, please see {reference} or ask for more advice in the forums.
Elk says that as an inspector, he usually requires a condition report on all chimneys more than 10 years old prior to issuing a permit. Part of the report says whether a cleaning is required. {Does this report need to come from a sweep? Should they get this report before or after doing the stuff in this procedure?}
Tools required:
Good flashlight, trouble light, or other strong light source.
Hammer
Wire brushes, scrapers and other implements of destruction (optional depending on how much soot is covering things)
Eye protection and a dust mask or other breathing protection reccomended
Caulking gun with refractory cement (if needed)
Shop vacuum - This can be a very messy job, it helps to keep cleaning up the crud as you work.
Ladder(s) or other way to access top of chimney
1. The first check is mostly needed on fireplaces with a brick facing that only goes part way up the wall, with a combustible wall above. It is less likely to be a problem in full-faced floor to ceiling masonry faced fireplaces, but should be checked in any case. Unfortunately all to often, the masonry brick or facing is not sealed off properly. With your flash light, from inside the firebox, shine towards the front. Many times you will see a metal angle iron called a lintel, that supports the front edge of the fireplace opening. Look for a space between the front brick or masonry facing and the angle iron. There should NOT be any gaps! If there are, then chances are it is a direct path to the combustible header and framing material above. The easiest way to fill a gap is to apply refractory cement with a caulking gun, forcing as much cement into the space as possible.
2. Remove the damper plate. They are usually held in with cotter pins. Removing the damper plate makes the inspection and repair easier, and most insert installs will require that the plate be removed in any case.
3. Examine the existing firebricks in the entire firebox looking for cracks in either the bricks themselves or in the mortar joints between them. Any cracks must be repaired before the insert is installed {need instructions on how....}
4. Lightly tap the firebricks starting at the bottom and working to the top. Do this on both the back and each side. If filled with the required solid masonry the tapping sound should be "solid" and consistent. If you hear a hollow sound, especially as you work towards the top, you just discovered the prior mason took a short cut and the firebox is not NFPA 211 compliant. There may be leaves and all sorts of other combustibles in there, possibly construction debris, including blocks of wood. Time to fish your shop vac in there and clean it out. {How do you get into the space? Remove bricks? Go through the wall on the other side???} The area then needs to be filled with non combustibles. It is almost impossible to get mortar into the space, but filling it with sand is acceptable. {Would it be better to fill it with DRY concrete or mortar mix like "Sakrete" or equivalent, then drop some water on it? It seems like that would be better as the stuff would harden into masonry rather than possibly leak out at some time in the future}
5. With the damper plate open or removed, it is time to inspect the chimney. Shine the light up your chimney, look for creosote (which will need to be cleaned off). Look at your clay liners. Do they line up? Do you see missing mortar in the joints? Do you see any cracks or missing or flaking clay liners? {what do you do if there is a problem?} {Reference on what to do if not clay lined? If you don't have clay liners, further inspection and work will definitely be needed} Also note the size of the liner. This will determine whether you need to fully line the chimney to satisfy the cross-sectional area code. {Insert reference to this!}
(will continue in next post)
Gooserider
Mod Emeritus
Continued from previous...
6. The inside firebox inspection is done. Time now to head up to the top of the chimney to examine the chimney crown cap and look at your flue liner from the top down. First, look at the bricks. Are they intact? Is mortar missing in the joints? Are the top layers cracked or loose? Is the crown cap solid with no cracks present? Finally examine clay liners, as in step 5. Do you see creosote? Missing mortar in the joints or cracks? Missing or flaking tiles?
Gooserider
6. The inside firebox inspection is done. Time now to head up to the top of the chimney to examine the chimney crown cap and look at your flue liner from the top down. First, look at the bricks. Are they intact? Is mortar missing in the joints? Are the top layers cracked or loose? Is the crown cap solid with no cracks present? Finally examine clay liners, as in step 5. Do you see creosote? Missing mortar in the joints or cracks? Missing or flaking tiles?
Gooserider
b]Lets start with the masonry fireplace and then later expand it to ZC fireplaces. Inserts can only be installed in ZC fireplaces if they are listed to do so[/b]
Does this report need to come from a sweep requires a condition report on all chimneys more than 10 years old prior to issuing a permit.
Part of the report says whether a cleaning is required. {? Should they get this report before or after doing the stuff in this procedure?}
When obtaining a permit come prepared I think a separate wiki is needed on the permitting process. In another separate wiki a sample condition report the homeowner could fill out as proof of inspection and having done one with a signed affidavit signed by the homeowner. Also qualified to do an inspection on a masonry chimney, would be a licensed masonry contractor. Part of being prepared is If the owner took pictures detailing the firebox and chimney condition many inspectors will consider that as proof of condition also proof it is clean. If in doubt, ask if the inspector would do a prelim inspection. I have done that before, If I see enough evidence, that I have questions about, I then will require a licensed sweep or mason to provide me a report.
{need instructions on how....} to repair the fire box?
A post this past week I detailed how to scrape out loose mortar and v grove out cracks and apply refractory cement.
Hopefully a shop vac has a flexible hose that can be placed in the voids behind the damper and firebrick void. I use a dental type mirror to check but with a flashlight and mirror angled down one can check for debris.
I like your idea of pouring dry concrete then water
If you don't have clay liners, further inspection and work will definitely be needed} Also note the size of the liner. This will determine whether you need to fully line the chimney to satisfy the cross-sectional area code. {Insert reference to this!}
If you don’t have a any liner a full approved S liner is required. If there are missing mortar joint in the or signs of damage to the clay flue liners a full ss liner is required if the liners can not be reached for repairs.
Cross-sectional code exterior chimney 2 times the flue collar is permitted. Meaning for a 6” flue collar stove it can only be vented in an 8/8 flue the 8/12 is too large requiring a full liner
If an interior chimney the 3 times the cross-sectional area is ok meaning one can direct connect into an 8/12 clay flue but not into
a 12/12. Even though code compliant draft wise I recommend full liners in larger than 8/8 clay flues for 6” stove collars
Does this report need to come from a sweep requires a condition report on all chimneys more than 10 years old prior to issuing a permit.
Part of the report says whether a cleaning is required. {? Should they get this report before or after doing the stuff in this procedure?}
When obtaining a permit come prepared I think a separate wiki is needed on the permitting process. In another separate wiki a sample condition report the homeowner could fill out as proof of inspection and having done one with a signed affidavit signed by the homeowner. Also qualified to do an inspection on a masonry chimney, would be a licensed masonry contractor. Part of being prepared is If the owner took pictures detailing the firebox and chimney condition many inspectors will consider that as proof of condition also proof it is clean. If in doubt, ask if the inspector would do a prelim inspection. I have done that before, If I see enough evidence, that I have questions about, I then will require a licensed sweep or mason to provide me a report.
{need instructions on how....} to repair the fire box?
A post this past week I detailed how to scrape out loose mortar and v grove out cracks and apply refractory cement.
Hopefully a shop vac has a flexible hose that can be placed in the voids behind the damper and firebrick void. I use a dental type mirror to check but with a flashlight and mirror angled down one can check for debris.
I like your idea of pouring dry concrete then water
If you don't have clay liners, further inspection and work will definitely be needed} Also note the size of the liner. This will determine whether you need to fully line the chimney to satisfy the cross-sectional area code. {Insert reference to this!}
If you don’t have a any liner a full approved S liner is required. If there are missing mortar joint in the or signs of damage to the clay flue liners a full ss liner is required if the liners can not be reached for repairs.
Cross-sectional code exterior chimney 2 times the flue collar is permitted. Meaning for a 6” flue collar stove it can only be vented in an 8/8 flue the 8/12 is too large requiring a full liner
If an interior chimney the 3 times the cross-sectional area is ok meaning one can direct connect into an 8/12 clay flue but not into
a 12/12. Even though code compliant draft wise I recommend full liners in larger than 8/8 clay flues for 6” stove collars
webbie
Seasoned Moderator
Thanks - Goose and Elk. I will read, make changes and add diagram...that is if you are finished (goosed)
As Elk says, prefabs are for another subject. I may even have posted a wiki on this - I'll have to check.
Yes:
https://www.hearth.com/econtent/index.php/wiki/Convert_Prefab_Fireplace/
a short wiki on the prefab subject - remember, any registered member can add to these - just click the edit button on the top right of the wiki article
As Elk says, prefabs are for another subject. I may even have posted a wiki on this - I'll have to check.
Yes:
https://www.hearth.com/econtent/index.php/wiki/Convert_Prefab_Fireplace/
a short wiki on the prefab subject - remember, any registered member can add to these - just click the edit button on the top right of the wiki article
webbie
Seasoned Moderator
OK, here is the start of the inspection article on wiki - thanks to Elk and Goose.
https://www.hearth.com/econtent/index.php/wiki/Inspect_your_chimney_before_installing_insert/
https://www.hearth.com/econtent/index.php/wiki/Inspect_your_chimney_before_installing_insert/
Gooserider
Mod Emeritus
Over all looks good, but I did see a problem in section 5
Note the sentence fragment in bold... In my initial post, I said that a reference was needed as to what to do if no liners, it looks like that got lost in the editing...
There may be a few other minor points I'd like to clean up - what is the process with this wiki software?
Gooserider
Note the sentence fragment in bold... In my initial post, I said that a reference was needed as to what to do if no liners, it looks like that got lost in the editing...
There may be a few other minor points I'd like to clean up - what is the process with this wiki software?
Gooserider
webbie
Seasoned Moderator
Just hit the edit button at the top of the article and fix/edit.
I did remove some stuff, as one article cannot tell all - so give it a shot.
There is a link on the front wiki page to the code you would use if you want link, etc....
Also, new articles can easily be created just by entering the title of the proposed article in the "Find page or create page" box.
I did remove some stuff, as one article cannot tell all - so give it a shot.
There is a link on the front wiki page to the code you would use if you want link, etc....
Also, new articles can easily be created just by entering the title of the proposed article in the "Find page or create page" box.
Gooserider
Mod Emeritus
I've done some additional edits on the wiki article to add in the stuff mentioned above, feel free to look it over. If you see any problems, feel free to let me know or fix them, however I am considering this to be a done project for now.
Gooserider
Gooserider
webbie
Seasoned Moderator
Thanks - the good thing about wiki is that you can always add or edit. My hope is that eventually we will have thousands of entries there and hundreds of regular contributors.
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