Thread: Fireblocks around chimneys

My reading of R1003-19 says that there should be fireblocking around steel fireplace flues (or anything else) when they enter the attic. I should never be able to stand in the attic and look down into the 1st floor. However, on > 90% of the chimneys I see a big gaping hole and the top of the steel (or brick) firebox below. I always write it up as a fire hazard but am I being too picky? When I'm not doing HI's I'm a fire inspector so I tend to be tough on fire issues. Any advice from a better expert than me?

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I always write it up as a fire hazard but am I being too picky?

NO!
Basic home construction 101. One does not need to be an expert to point this out.
JMHO

Originally Posted by David Edenburn

My reading of R1003-19 says that there should be fireblocking around steel fireplace flues (or anything else) when they enter the attic. I should never be able to stand in the attic and look down into the 1st floor. However, on > 90% of the chimneys I see a big gaping hole and the top of the steel (or brick) firebox below. I always write it up as a fire hazard but am I being too picky? When I'm not doing HI's I'm a fire inspector so I tend to be tough on fire issues. Any advice from a better expert than me?

You are doing the right thing.

Originally Posted by David Edenburn

My reading of R1003-19 says that there should be fireblocking around steel fireplace flues (or anything else) when they enter the attic. I should never be able to stand in the attic and look down into the 1st floor. However, on > 90% of the chimneys I see a big gaping hole and the top of the steel (or brick) firebox below.

Being as you are a fire inspector, you hold more power than we, home inspectors, do (we have no power). I recommend you explain to the Fire Chief what you explained above, and ask him to explain it to the Building Official, who can then explain it to his inspectors.

">90%" That's a lot of "not good" building practice and it needs to be curtailed as soon as possible.

I always write it up as a fire hazard

It is. Good inspecting.

but am I being too picky?

Absolutely not.

When I'm not doing HI's I'm a fire inspector so I tend to be tough on fire issues. Any advice from a better expert than me?

As a fire inspector, *YOU* are the expert, not us. \

Home inspectors have no teeth, all we can do is gum them to death. As a fire inspector, you have teeth, bite their arses off!

They (the building department and inspectors) should know better than to allow that.

R1003.19 Chimney fireblocking. All spaces between chimneys and floors and ceilings through which chimneys pass shall be fireblocked with noncombustible material securely fastened In place. The fireblocking of spaces between chimneys and Wood joists, beams or headers shall be self-supporting or be Placed on strips of metal or metal lath laid across the spaces between combustible material and the chimney.

R1003.19 applies to Masonry Chimneys, not Pre-fabs.

The paragraph you're looking for is M1802.9 wherein is states: "Vent and chimney installations shall be fireblocked in accordance with R602.8, which says fireblocking shall be provided "At openings around vents, pipes, ducts, cables and wires at ceiling and fllor level, with an approved material to resist the free passage of flame and products of combustion."

Does the lack of fireblocking at the aforementioned locations in itself, present a "fire hazard"? I think of a physical hazard like when there is contact of combustible wood against a potentially hot metal pipe. Or, a thick build-up of creosote inside the chimney.

The way I see it, if the fireplace and (or) chimney caught fire, having these safety related components in place would provide the following: 1. Fireblocking should allow more time in resisting the spread of flames and products of combustion. If occupied, better odds of getting out of the house in time. 2. Better odds of avoiding a catastrophic loss of the property. Fire department has more time to respond and to take action.

Originally Posted by Hank Spinnler

Does the lack of fireblocking at the aforementioned locations in itself, present a "fire hazard"? I think of a physical hazard like when there is contact of combustible wood against a potentially hot metal pipe. Or, a thick build-up of creosote inside the chimney.

The way I see it, if the fireplace and (or) chimney caught fire, having these safety related components in place would provide the following: 1. Fireblocking should allow more time in resisting the spread of flames and products of combustion. If occupied, better odds of getting out of the house in time. 2. Better odds of avoiding a catastrophic loss of the property. Fire department has more time to respond and to take action.

If it is a safety related component that is missing, is that not a fire hazard???
Seems like semantics to me. Kind of like egress windows that are inoperable, not a fire hazard unless you need them in a fire.

I don't see it as an actual risk or even a theoretical risk. Would the lack of fireblocking actually cause a fire? If so, how?

On some occasions, I have seen where do-it-yourselfers have dumped trash or strips of fiberglass batt insulation have fallen down the chase and on top of the metal insert. I write this up as a fire hazard.

Like your window analogy, if the chimney damper will not open, you'd quickly have smoke pouring into your home. A fire hazard.

Bottom line, I do write this type of thing up and when warranted, provide the applicable code reference. I just don't use the phrase "fire hazard".

Any other opinions?

Fire blocking is a required part of safe construction to limit or contain a fire. No it won't actually start a fire but neither does a FPE breaker (for the most part) it is the overloaded or shorted wire that is the immediate cause, the breaker just limits or contains the hazard.
But I see your point and we can bring analogies on end.
I don't know that I have ever labeled missing fire-blocking as a "fire Hazard" per se. I just note that it is missing, required, and the purpose.

Good points Jim. David, did this help you?

Here is an open chimney chase as it passes through the attic. The C.O. was given while I was there and two county inspectors chose to ignore this as well as 14 other code violations & manufacturer's installation instructions.

Hank, what's the red triangle indicating?

Neal, that's outlining where the osb sheathing should be installed to seal off the chase. I don't want to see the metal chimney in the attic. Per 2006 IRC 602.8: Fireblocking shall be provided to cut off all concealed draft openings (both vertical and horizontal) and to form an effective fire barrier betrween stories, and between a top story and the roof space.

Originally Posted by Hank Spinnler

Neal, that's outlining where the osb sheathing should be installed to seal off the chase. I don't want to see the metal chimney in the attic. Per 2006 IRC 602.8: Fireblocking shall be provided to cut off all concealed draft openings (both vertical and horizontal) and to form an effective fire barrier betrween stories, and between a top story and the roof space.

I guess I would have to do some reading but I do not believe there is a concern with the flue running thru an attic.

It is not a concealed draft opening. It is a closed flue pipe. As long as it is sealed off at ceiling level I don't see a concern. Unless you are saying you went over there and opening around the flue goes all the way to the fireplace thru the ceiling.all the way down.

The red highlight above is just stating at the ceiling height not thru the entire attic.But I will re-read things.

Originally Posted by Hank Spinnler

Neal, that's outlining where the osb sheathing should be installed to seal off the chase. I don't want to see the metal chimney in the attic.

Hank, if that were the case, all metal Bvents or chimneys should be enclosed with a wood chase.

I agree with Ted.

The shot in the attic shows a partial photo of a sheathed chase inside the middle-third area of the attic. There was a leak around the flashing on the roof. Here, some AHJ's require metal chimneys be fully enclosed and some do not. Oftentimes, I will see a framed chase in the attic without sheathing. I'm aware that this does not apply to Type B vents.

Hank,

Red bold is mine for highlighting:

Originally Posted by Hank Spinnler

Neal, that's outlining where the osb sheathing should be installed to seal off the chase. I don't want to see the metal chimney in the attic. Per 2006 IRC 602.8: Fireblocking shall be provided to cut off all concealed draft openings (both vertical and horizontal) and to form an effective fire barrier betrween stories, and between a top story and the roof space.

Using your thinking, no exposed chimneys would be allowed "between stories" either.

What that is saying is this:
- 2006 IRC 602.8: Fireblocking shall be provided to cut off all concealed draft openings (both vertical and horizontal) and to form an effective fire barrier ...
- - between stories, ... i.e., at floor/ceiling assemblies
- - and between a top story and the roof space, i.e., at ceiling/roof assemblies - there is no stated requirement to fireblock the roof "space", i.e., the "attic", not the "roof".

The chimney is allowed to be exposed in the attic, however, (going back to the original post's photo) you should NOT be able to look down from the attic and see the fireplace below - there should be fireblocking at the first floor ceiling, at the second floor ceiling (using a two story house as an example).

Thanks Jerry. To clarify why I think this way - some AHJ's in the larger municipalities in GA require both the fireblocking between stories as well as the space between the attic ceiling and the roof.

I think the ICC could clean up this passage a little. Others seem to interpret it the way I described, thinking it's really talking about fireblocking the attic space.

The OP's photo shows a factory bult Fp--not masonry, which Chuck correctly pointed out does not apply to the R1000 section but R602.8. However, there is another fire related defect here. The factory chimney requires an attic insulation shield to maintain the stated clearance to combustibles (usually 2" on factory chimney but not always) and to provide for cooling air circulation. The lack of a listed firestop and surrounding fireblocking allows for insulation to fall down on top of the fireplace and chimney, which is a direct fire hazard. The lack of a listed firestop where required by the listing means the chimney does not have its requisite laternal support either. Even with the proper firestopping and fireblocking, you would need the attic insulation shield.

Something does not have to present an imminent threat to be considered a fire hazard.

I highly recommend you all adopt the ANSI alert word system regarding reporting hazards:
notice-used for non-safety related FYI
caution!-something may go wrong and if it does it will probably result in damage to property and possibly personal injury
warning!-something is likely to wrong and when it does, it will result in significant damage to property and significant personal injury
danger!-something definitely will go wrong and when it does it will result in catastrophic damage to property with resulting personal injury or death.

Notice how the likelihood of the incident escalates with the increasing severity of damage and personal injury.

I would rate this defect under *warning*.

I used to interpret the code as requiring the vertical fireblocking to the roof deck but Dale Feb explained it to me that the IRC does not, while Calif. does. Yes, the presence of vertical fireblocking or a fully contained chase can mean the difference btw a $30-50K fire and one another decimal place over.

HTH,