Chimney cap required?

[Gene South]

I cannot find a building code requiting a "chimney cap". I can find codes that "spark arrestors" (chimney caps), must be removable, etc, but nothing stating a cap is required. I would like to hear other inspectors thoughts on whether a chimney cap is required.

[Nick Ostrowski]

I think it's just a difference in terminology. I believe they are both the same thing. Kind of like one person calling it a hose bib and another calling it a spigot.

[Gene South]

Hi Nick, Thanks. What I meant was if a chimney cap (or spark arrestor) is installed, then it must be removeable for access for cleaning and maintenance. But I can find no where that says a chimney cap is required installed in the first place. The reason I am asking I am working in a nice neighborhood of new homes and on one house, the builder did not install a chimney cap, but on the others, he did. I don't want to make a big deal of it only to find out later it is the builder's option and not required.

[Mike Lamb]

This is for a fireplace I assume? If it is a manufactured unit the manufacturer's instructions or the instructions with the vent might tell you. Type L vents need a cap. Unused flues need to be capped.

I read or heard a while ago of a homeowner suing her home inspector because a squirrel had come down the chimney and did a lot of damage to the home. She claimed her inspector should have warned her that this could happen so it might be prudent to advise your client to get one whether it's required or not.

[Nick Ostrowski]

Whether required or not, I always recommend one. Rain, snow, tree debris, birds, and animals could get inside the chimney otherwise.

[Nolan Kienitz]

Whether required or not common sense tells one to advise that it is not there and needs to be installed.

I was at a home just the other day that didn't have one (brick/stone f/p) and the damper was rusted solid due to rain having had it's way for many years.

.

[BridgeMan]

I read or heard a while ago of a homeowner suing her home inspector because a squirrel had come down the chimney and did a lot of damage to the home. She claimed her inspector should have warned her that this could happen so it might be prudent to advise your client to get one whether it's required or not.

The homeowner (or anyone, for that matter) can sue anyone, for anything. Wrong color shirt? Go ahead and file a lawsuit against the guy, for causing her hives to act up again. He should have known she was allergic to blue . . . or red . . . or purple . . . or brown . . . ad nausea. Back in my working days as District Bridge Engineer for the DOT, I was sent a "notice of intent to sue" by a lawyer representing the widow of a drunk who ran into a pier column on one of my bridges (going close to 80 mph in his Corvette). The lawyer's wording was quite precise, stating that the bridge was obviously constructed in the wrong location, and had it not been there, his client would still be alive.

Protecting people from themselves, that's what it's all about.

But getting back to the OP's question--I could find nothing in the IRC requiring chimney caps. Maybe Peck or Watson will come back with a reprimand, correcting me, after they've punished us enough (for scolding them for bickering) by not posting for a while.

[Vern Heiler]

A chimney cap is the mortar or metal cap that covers the top of the chimney. The "rain cap and or screen" is what prevents rain and small animals from entering the flue. Rain caps and screens are not required. Some people leave the rain cap and screen off intentionally to provide habitat for the chimney swift which has lost many of its breeding spaces due to rain caps.

[Joe Funderburk]

A chimney cap is the mortar or metal cap that covers the top of the chimney.

That's the chimney crown.

[Joe Funderburk]

There is no requirement in the IRC for a chimney cap or spark arrestor, but like others, I always recommend one. I once opened the damper and a raccoon that appeared to me as big as a bear cub almost fell out on my face. I felt a sudden urge to go to the bathroom. The seller had to pay $300 to have it removed from the flue by a wildlife specialist.

[Garry Sorrells]

There is no requirement in the IRC for a chimney cap or spark arrestor, but like others, I always recommend one. I once opened the damper and a raccoon that appeared to me as big as a bear cub almost fell out on my face. I felt a sudden urge to go to the bathroom. The seller had to pay $300 to have it removed from the flue by a wildlife specialist.


Dang.... I didn't know that I was a "wild life specialist" after removing birds, squirrels, possum and raccoons. Like the title. Will have to use it the next time someone calls with the problem. Just thought the title was "crazy to do it". Nothing like rasssling a critter out of a house to make your day.

[Vern Heiler]

That's the chimney crown.

After looking around I have found it called: mortar cap, crown, and top seal.
Just another one of those things called by many names.

[Bob Harper]

NFPA 211-2010
3.3.18.1 Chimney cap. A protective covering or housing for the top of a chimney intended to prevent the entry of rain, snow, animals and birds and to prevent downdrafts.

3.3.50 Crown. A sloped covering for the top of a masonry chimney that is designed to shed water away from the flue liner and the chimney and to allow for expansion and movement of the flue liner.

4.6.1 Design. Chimney or vent caps, where required fr the termination of chimneys or vents shall be designed to prevent the entry of rain, snow and birds and other animals.

4.6.2 Rain cap height. The minimum distance from the underside of an unlisted rain cap to the top of covered flues shall be the lesser dimension of the width or depth of the covered flue. Where more than one flue is covered, the lesser dimension of the highest flue shall be used.

4.6.3 Screening. Screening material attached to chimney or vent caps to prevent the entry of animals and insects shall not adversely affect the chimney or vent draft.

4.6.4 is a whole section on spark arrestors for solid fuel but you can look it up yourself.

[David OKeefe]

Does it matter if it's a flue for a fireplace or a furnace? I've seen chimneys with two flues but only one flue has a cap on it. Why is that?

[Garry Sorrells]

Does it matter if it's a flue for a fireplace or a furnace? I've seen chimneys with two flues but only one flue has a cap on it. Why is that?

1) Work done on furnace and cap was done as part of job.
2) Work done on fireplace and installed then.
3) Only was concerned on one flue with and not the other
4) Flues different sizes and brought the wrong size cap for one flue and never came back with the correct size.

[Bob Harper]

sweeps will often install a "multi-flue cap" or "chimney top protector" which is one big cap that covers most or all of the crown and flues. Some like the look but I don't install them. I have found recirculation of heater flue gases back into the home down the fireplace flue when the fireplace CAZ is depressurized. These caps tend to trap a fog of flue gases and can actually lead to damage, whether from creosote or acidic heater flue gases. I also find unlike most single caps, these can often cause wind-induced flow conflicts leading to smoke spillage. In order to get the clearance you need above the flue tile, these caps often have to ride very high making them look like a dog kennel on top of the chimney.

[Lon Henderson]

Fifteen years ago, I opened a damper and about twenty dead birds and one live pigeon fell into the fireplace. Three years later, I ran into the buyer at a store. She told me that they had the top of the chimney screened off. The birds tore a hole in the screening and got back into the chimney.

Somewhere, Hitchcock smiled ever so slightly.

[Joe Funderburk]

Does it matter if it's a flue for a fireplace or a furnace? Not to me. I recommend a cap/spark arrestor on any chimney that doesn't have one, even if not in use to keep wildlife out.

[Bob Harper]

Fifteen years ago, I opened a damper and about twenty dead birds and one live pigeon fell into the fireplace. Three years later, I ran into the buyer at a store. She told me that they had the top of the chimney screened off. The birds tore a hole in the screening and got back into the chimney.

Somewhere, Hitchcock smiled ever so slightly.

Birds aren't going to rip open the std. 18ga. ss mesh on professional chimney caps. They can usually resist racoons and squirrels.

[ROBERT YOUNG]

A chimney cap is the mortar or metal cap that covers the top of the chimney. The "rain cap and or screen" is what prevents rain and small animals from entering the flue. Rain caps and screens are not required. Some people leave the rain cap and screen off intentionally to provide habitat for the chimney swift which has lost many of its breeding spaces due to rain caps.

It is called Chimney crown (http://www.google.ca/url?sa=t&rct=j&q=&esrc=s&frm=1&source=web&cd=3&sqi=2&ved=0CFEQFjAC&url=http%3A%2F%2Fwww.masonryconstruction.com%2FIma ges%2FHow%2520to%2520Construct%2520a%2520Chimney%2 520Crown_tcm68-1375172.pdf&ei=lBH6UL2NEpLq0QGytoFI&usg=AFQjCNGrAZeVCacACvkz098zC9egBYxfYQ&sig2=BxLDUd85EMmPyJuENPFugg).

[ROBERT YOUNG]

I cannot find a building code requiting a "chimney cap". I can find codes that "spark arrestors" (chimney caps), must be removable, etc, but nothing stating a cap is required. I would like to hear other inspectors thoughts on whether a chimney cap is required.

A chimney Crown.
A cap goes atop the clay or metal liners or flues.

The anatomy of a chimney and fireplace. (http://www.highschimney.com/articles/parts-chimney-anatomy-fireplace-chimney-guide/)

The masonry chimney must have a crown the exceeds the masonry periphery (the brick) by 4" on all sides.
The underside of the "Crown" must have a rain stop, curff or notch ( concave) one inch back from the leading edge on the underside.
To stop water tension.
The 4" over hang acts like an eave on a roof shielding the walls.
Man made crowns are 4" thick and taper to 2.5". From the flue liner (4") to the periphery at a 15% or more
The liners protrude 6" to act as a wind break.
Hope that helped.

A chimney crown. The cap would be metal hat to stop rain from going down the liners or flues.

[Lon Henderson]

Regional differences in lingo......around here the crown is called the chimney cap.

[BridgeMan]

And around here (in the 5 states I've lived in) the chimney cap is called a crown.

And angle iron is actually steel angle. And most I-beams are actually W-beams.

[ROBERT YOUNG]

NFPA 211-2010
3.3.18.1 Chimney cap. A protective covering or housing for the top of a chimney intended to prevent the entry of rain, snow, animals and birds and to prevent downdrafts.

3.3.50 Crown. A sloped covering for the top of a masonry chimney that is designed to shed water away from the flue liner and the chimney and to allow for expansion and movement of the flue liner.

4.6.1 Design. Chimney or vent caps, where required fr the termination of chimneys or vents shall be designed to prevent the entry of rain, snow and birds and other animals.

4.6.2 Rain cap height. The minimum distance from the underside of an unlisted rain cap to the top of covered flues shall be the lesser dimension of the width or depth of the covered flue. Where more than one flue is covered, the lesser dimension of the highest flue shall be used.

4.6.3 Screening. Screening material attached to chimney or vent caps to prevent the entry of animals and insects shall not adversely affect the chimney or vent draft.

4.6.4 is a whole section on spark arrestors for solid fuel but you can look it up yourself.

Thanks Bob. Missed your post.
All the best.

[Gene South]

Here are two photos related to the original house that started this thread. The chimney without the cap (the hooded metal cap) is the house in question. The chimney with the cap (metal cap) is one of the neigboring houses and the way the rest of the neighborhood chimneys look. When I say "cap" I am referring to the metal hood that is mounted on top of the masonry chimney. The masonry flatwork on top of a chimney (and below the cap), I have always referred to as a "crown" which I believe is the correct terminology. My original question that started this thread was whether a cap (metal hood cap) was required. I am since sure that it (the metal hood cap) is not required. Thank everyone for your input.

[Raymond Wand]

The chimney in the left requires a proper crown and flue hood.

[Bob Harper]

Here are two photos related to the original house that started this thread. The chimney without the cap (the hooded metal cap) is the house in question. The chimney with the cap (metal cap) is one of the neigboring houses and the way the rest of the neighborhood chimneys look. When I say "cap" I am referring to the metal hood that is mounted on top of the masonry chimney. The masonry flatwork on top of a chimney (and below the cap), I have always referred to as a "crown" which I believe is the correct terminology. My original question that started this thread was whether a cap (metal hood cap) was required. I am since sure that it (the metal hood cap) is not required. Thank everyone for your input.

The picture on the right shows what appears to be a listed termination under a 'shroud'. Unless you can find documentation to the effect this shroud is listed for use with this fireplace and termination then it is an illegal fire hazard and must be removed.

[BridgeMan]

Unless you can find documentation to the effect this shroud is listed for use with this fireplace and termination then it is an illegal fire hazard and must be removed.

Or properly evaluated by a qualified individual, with written documentation to support said evaluation.

[David Caldwell]

Ladies and Gentlemen,

Please correct me if I am misinterpreting this: IRC R1003.9.1 states, "Masonry chimneys shall have a concrete, metal or stone cap, slopped to shed water, a drip edge and a caulked bond break around any flue liners in accordance with ASTM C 1283" R1003.9.2 states, Where a spark arrestor is installed on a masonry chimney, the spark arrestor shall meet all fo the following requirements:, then lists 1 - 4. I interpret this "Cap" to be something that prevents things like rain, animals, insects, rodents, etc. from getting in the chimney. I am still learning here, but it makes logical sense to me that a chimney should have this item for just the a fore stated reasons. Thanks in advance. :)