Fire Stop/Draft Stop Requirement

[Nick Ostrowski]

I looked at a 14-15 year old townhome yesterday where none of the penetrations through the basement ceiling were firestopped or draft stopped. I recommended sealing them for safety but it got me to wondering when fire stopping/draft stopping became a building requirement.

Any ideas?

[A.D. Miller]

I looked at a 14-15 year old townhome yesterday where none of the penetrations through the basement ceiling were firestopped or draft stopped. I recommended sealing them for safety but it got me to wondering when fire stopping/draft stopping became a building requirement.

Any ideas?

History of Firestops in North America (http://ahering.webs.com/history_of_firestops_in_north_america.htm)

[A.D. Miller]

NO: Assuming that townhome was not a boat, this will be more helpful:

Welocm Text (http://www.jleinc.com/firestop/Pages/Codes.htm)

[Jerry Peck]

but it got me to wondering when fire stopping/draft stopping became a building requirement.

Any ideas?


To clarify, you are referring to firestopping and draftstopping versus fireblocking, correct?

[Nick Ostrowski]

Correct Jerry.

Thanks for the info Aaron.

[A.D. Miller]

To clarify, you are referring to firestopping and draftstopping versus fireblocking, correct?

JP: I don't think fireblocking pertains here. He was discussing penetrations of a ceiling, presumable by utility elements. Isn't fireblocking something quite different?

Fire blocking is a term commonly used to describe the blocking used at the mid span of a wood framed area to inhibit the advance of fire within a concealed space, thereby maintaining the structural integrity of the building during a fire. It is described in the building codes (IRC/IBC) as follows:

FIREBLOCKING. Building materials installed to resist the free passage of flame to other areas of the building through concealed spaces.

Fireblocking is seldom required in residential construction any more (there are some exceptions), however there is a process called "Draft Stopping" that is common in all wood framing and used extensively in residential construction.

Fireblocking is most commonly seen in fire rated assemblies (walls, floors and ceilings). It should be made of noncombustible materials or a rated assembly that incorporates combustible materials (rated assemblies have been tested and are built to very strict standards). There are some applications that allow standard dimensional lumber (such as 2x4's) to be used. Check with your specifications or code requirements in your area for clarification. Most can be placed using standard forms of attachment, such as nails, screws or staples, and some require special attachment processes. If special attachment is required, it will usually be spelled out in the design specifications (see you plans and details or assembly specifications).

Draft stopping is described in the building codes (IRC/IBC) as follows:

DRAFTSTOP. A material, device or construction installed to restrict the movement of air within open spaces of concealed areas of building components such as crawl spaces, floor/ceiling assemblies, roof/ceiling assemblies and attics.

Draft stopping is required to be located in areas where a transition from horizontal to vertical or vertical to horizontal occurs. It is also required in spaces over a prescribed volume or square footage to limit how much air is available to feed a fire. The intent is to starve the fire of oxygen before it can grow to a point that it can cause severe damage to the building or structure. As draft stopping is used to limit air and not stop fire it can be build of almost any material approved by the building codes. We commonly use sheet metal, wood framing members, insulation or expanding foam for draft stopping.

[Jerry Peck]

JP: I don't think fireblocking pertains here. He was discussing penetrations of a ceiling, presumable by utility elements. Isn't fireblocking something quite different?

That is what I was clarifying.


Fire blocking is a term commonly used to describe the blocking used at the mid span of a wood framed area to inhibit the advance of fire within a concealed space, thereby maintaining the structural integrity of the building during a fire. It is described in the building codes (IRC/IBC) as follows:


Fireblocking is oneword, not two words. ;)

Fireblocking is also what is done at the top plate and the bottom plate, not just mid-span.

[A.D. Miller]

Fireblocking is oneword, not two words. ;)

JP: Two words lusting after each other.:D


Fireblocking is also what is done at the top plate and the bottom plate, not just mid-span

JP: Well hell, I only cut and pasted that crap from somewhere else. I did not read it all - I knew you would.:eek:

[Jerry Peck]

JP: Well hell, I only cut and pasted that crap from somewhere else. I did not read it all - I knew you would.:eek:


I didn't read it either, I just presumed it said the right stuff ... does that mean I have to go back and read it? :confused:

[Nick Ostrowski]

I didn't read it either, I just presumed it said the right stuff ... does that mean I have to go back and read it? :confused:

Well I hope somebody read it because I gave up.

[Jerry McCarthy]

Definitions – 2009 IRC

FIREBLOCKING: Building materials installed to resist the free passage of flame to other areas of the building through concealed spaces.

DRAFT STOP: A material, device or construction installed to restrict the movement of air within open spaces of concealed areas of building components such as crawl spaces, floor-ceiling assemblies, roof-ceiling assemblies and attics.

Definitions: 2007 California Building Code - Ditto

[Nick Ostrowski]

So does anybody know when either fireblocking or draft stoppage became a requirement?

[Jerry Peck]

Sometimes 'firestops' and 'fireblocks', or 'firestopping' and 'fireblocking' are used interchangeably, although there are subtle differences by most uses. Here is an example of using those terms interchangeably:
- From the IRC.
- - E3302.3 Penetrations of firestops and draftstops. Penetrations through fire blocking and draftstopping shall be protected in an approved manner to maintain the integrity of the element penetrated.

Note that even "fireblocking" is "fire blocking" in there too.

Fireblocking is as WC Jerry posted:
- FIREBLOCKING: Building materials installed to resist the free passage of flame to other areas of the building through concealed spaces.

Firestopping usually used as referring to sealing around penetrations through fire-resistance rated assemblies.

Here are two examples:
- The frame wall was fireblocked at the ceiling by the installation of minimum thickness 2x wood which was tight fitting at its ends and edges.
- The concrete floor between stories where the DWV pipes run vertically through were firestopped around where the pipes penetrated the floor through holes in the floor.

Draftstopping, on the other hand, is simply to reduce the size of concealed areas to prevent or restrict the movement of air to stop the spread of smoke and combustion by-products.

Not sure if that helps or makes it muddier?

[Jerry Peck]

So does anybody know when either fireblocking or draft stoppage became a requirement?


I'm guessing after the Great Chicago fire is when more attention started to be paid to it.

Otherwise, I know that where I was in the 1960 that fireblocking was required, and looking at most older framed homes after balloon framing changed to platform framing are all fireblocked, and even many of the balloon framed homes were fireblocked at the floor, the ceiling, and at the 4 foot level (mid story). Go back past that into older balloon framed structures and you will be able to fish wires from the crawlspace to the attic, meaning there is no fireblocking in the walls.

Is that vague enough of a time frame?

The better way to ask the question would be something like: 'Was fireblocking required in 19XX?'

[A.D. Miller]

Here's another that you can pick the nits from:

Firestopping & Fireblocking: What's the Difference? - Cover Story - PM Engineer (http://www.pmengineer.com/Articles/Cover_Story/a06512d743298010VgnVCM100000f932a8c0)____

[A.D. Miller]

There certainly does not seem to be a wide-spread consensus on the terminology in question.

As per the OED, the term fireblock was first used across the Pond:

d. Pertaining to the fire of a hearth or furnace, as fire-bellows, -block, -blower, -brush, -cheek, â€*-cricket, -door, -grate, -nook, -rake, -set, â€*-stock, -stove.
1836 F. Mahoney Rel. Father Prout ii. (1859) 247, I+made the kindling *fireblocks shine.

But then, that has nothing to do with the usage in question.

Webster's Third New International Unabridged says this about it:

fire blocks (yes JP, those are two distinctly separate words, and yes, it does appear to be plural) n pl : pieces of wood nailed horizontally between studs or joists to prevent the spread of fire and hot gases.

Please note that there is no mention whatsoever of the term "fireblock", either as a noun or a verb, or "fireblocking".

Random House Second Edition Unabridged has no entry.

Dictionary.com has no entry.

American Heritage Dictionary of the English Language Fourth Edition has no entry.

Microsoft Encarta has no entry.

Wictionary.com has not entry.

Architectural Graphics Standards Eight Edition shows an illustration depicting a "fireblock" as a "draft stop".

The Encyclopedia of Building and Construction Terms says:
Fire Blocking - Short wood pieces placed between studs, joists or rafters to prevent the spread of fire. Also called FIRE STOPS.

The Illustrated Dictionary of Building Materials and Techniques says:
fire block - 1. One of a series of blocks of wood nailed horizontally between wall studs to prevent the spread of flame and smoke in the airspace between whose studs. 2. Any concealed, tightly enclosed space that serves such a purpose; also referred to as a fire-stop or draft stop.

Carpentry & Building Construction Third Edition shows illustrations depicting "firestopping".

3M seems to think this sealant is designed for sealing fire blocks:
Shop 3M: 3M Fire Block Sealant FB 136 (http://www.shop3m.com/3m-fire-block-sealant-fb-136-15l6fsm7gv.html)

Boss sees it differently:

http://www.efi.org/wholesale/specs/Foam%20Products%20Spec%20Sheets/BOSS%20136%203500-65.pdf

I suppose, as Juliet said:

"What's in a name? That which we call a rose
By any other name would smell as sweet."

[Jerry McCarthy]

As an apprentice carpenter in the very early 50s my job was installing fireblocking in all vertical walls of a building. The job was only slightly less boring than lying on my back in the foundation crawl space nailing off the floor joist herringbone blocking?

[A.D. Miller]

As an apprentice carpenter in the very early 50s my job was installing fireblocking in all vertical walls of a building. The job was only slightly less boring than lying on my back in the foundation crawl space nailing off the floor joist herringbone blocking?

JM: I suffered the same indignations. Fireblocks, framing furr-downs, combustion air chases for water heaters, look-out blocks for the cornice carpenters - grunt work . . .:D

[Jerry McCarthy]

AM; How many home inspectors or even today's carpenters (if you can call them that) know what "herringbone" is? :confused:

[A.D. Miller]

AM; How many home inspectors or even today's carpenters (if you can call them that) know what "herringbone" is? :confused:

JM: Few likely suspects on that note. The same number that own plumb bobs; know how to cut a roof or a staircase with a framing square and a hand saw; know what it means to scribe trim; hell, the list is long, man.:D

And, how many do you think could frame all day using a 28-oz. hammer or a rig axe? Carry drywall up stairs 8 hours a day? Load roofs with shingles in the absence of a laddivator or a front end loader? How many can even spell trigonometry? Cut rafter tails overhead with an 8-in worm-drive saw?

Let's face it, the real men left the building.:eek:

[Jerry McCarthy]

Add to that; cut a stair stringer, walk a top plate packing ceiling joist, coped an inside corner molding, rode a garbo-bucket, built their own scaffolding, actually wore carpenter overalls, dug a gummy pit and built a shelter around it, (today there called a portapotty and emptied by some guy driving what’s called “the honey wagon”), know what a pier pocket is, know how to plumb and line framed walls, placed concrete in foundation forms with a wheelbarrow & shovel, built their own trusses, knew that garages should be vented, built their own tool box and fully equipped it, know where Eskilstuna chisels and Sandvick hand saws come from, know how many teeth to the inch a finish and/or rip saw have, layout a building with a transit, oh but could we go on.
Bet there’s plenty of others on this board who know what we are taking about and probably many who don’t.

Signed: Tyrannous Rex :eek:

[A.D. Miller]

Add to that; cut a stair stringer, walk a top plate packing ceiling joist, coped an inside corner molding, rode a garbo-bucket, built their own scaffolding, actually wore carpenter overalls, dug a gummy pit and built a shelter around it, (today there called a portapotty and emptied by some guy driving what’s called “the honey wagon�), know what a pier pocket is, know how to plumb and line framed walls, placed concrete in foundation forms with a wheelbarrow & shovel, built their own trusses, knew that garages should be vented, built their own tool box and fully equipped it, know where Eskilstuna chisels and Sandvick hand saws come from, know how many teeth to the inch a finish and/or rip saw have, layout a building with a transit, oh but could we go on.
Bet there’s plenty of others on this board who know what we are taking about and probably many who don’t.

Signed: Tyrannous Rex :eek:

JM: If there are others on this forum dating back to the Jurassic Period, they'll probably chime in after nap time and just before the corkscrew spins.:D

[Jim Luttrall]

Man, I thought I was old!:D
Did they have electricity on site or did you have to fly a kite and catch your own?;)

[chris mcintyre]

JM: If there are others on this forum dating back to the Jurassic Period, they'll probably chime in after nap time and just before the corkscrew spins.:D

When I started, I worked for a fourth generation carpenter whose dad was in his seventies and worked everyday. As his helper when it was time to install a door lock I would fetch him the brace and bit, and the ratchet screw driver from behind the seat of the truck that no one was allowed to use.

I also remember the controversy when the son started letting a guy come by every other week to pick up all the dull saw blades for sharpening, the dad just shook his head and said "what is the world coming to."

[A.D. Miller]

Man, I thought I was old!:D
Did they have electricity on site or did you have to fly a kite and catch your own?;)

JL: No we had juice. You must be thinking of JP and JM.:D

But, double-insulated power tools were not all that common when I got into the business. There's nothing quite like having a metal-cased Skil saw short out on you while you're running it. It causes the muscles in your arm to contort aiming the saw at you leg. I never got cut, but witnessed a few who were not so lucky.

We also used many hand tools. Cutting a stair stringer with a power saw works, but is actually easier with a sharp hand saw. And yes CM, we all had sets of files and emery to sharpen our own.

We also used hand planes for some work, though routers were in common use. I still have 8 hand planes, including a Stanley No. 45 combined plow and beading plane. There is no better workout than hand planing boards, especially oak. However, these days, I use a router . . . while the hand planes take up a shelf in my office - relics of a bygone era.:D