Type III and type V building?

[MondoMarcus]

Hey everybody! I'm about done with my FIRE105 class and I have a simple question.

I understand that a type three building is considered normal construction, with limited combustibility and that a type five is wood frame, or mostly residential. But I have a difficult time looking at a building and deciding wich it is sometimes. How do I know if a local restraunt or fast food joint is wood frame or not?

And what materials does a type III consist of? It seems as though ordinary would be wood frame... wouldn't it?

Are their any websites that might show a picture of a structure and quiz me as to what type it is?

[PATF1engineer]

Ordinary construction (Type III) uses non-combustible materials for the exterior bearing walls, typically concrete block, and wood floors and roof structures. A wood frame building (Type V) has combustible bearing walls, normally wood studs. Both types can have brick veneers which can make it somewhat more difficult to tell them apart.

Type III is normally used for larger, often multi story, commercial or multi family types of structures. These buildings often have various types of trusses for the roof or the floor and often have flat roofs. There are practical limits to the size and height of wood frame buildings but you are starting to see them used more in non-residential applications. The roofs on wood frame buildings are normally not flat.

The best way to tell the difference is to pre-plan them. Beyond the obvious size and occupancy differences, ordinary construction will have thicker, heavier looking walls that you might be able notice by looking at door and window openings. The way the outside of the structure is sheeted can give you some ideas also. I think it is uncommon for someone to sheet over or use some type of siding on top of block; I think this is mostly done over wood framing. If you encounter a building that is either partly or totally sheeted in wood or another type of siding it is likely to be wood frame.

There is a lot of goofy stuff being built these days that consist of mixes of various materials and construction methods. You will come across structures that do not fit well into either category. You are starting see people push the limits of frame types of construction in small to mid size commercial buildings. I have seen lightweight trusses used with frame walls in commercial buildings. Scary stuff. I recommend picking up copies of "Collapse of Burning Buildings" by Vincent Dunn and "Building Construction for the Fire Service" by Francis Brannigan. Stay safe.

[FFEMTMills]

I have to agree with PATF1engineer on everything he said. When your looking at a Type III building think "downtown USA".

[Golzy12]

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[MondoMarcus]

Yes, I own a copy of Brannigan's book. It's a tough read for me but there is a lot of useful information packed into those pages.

So a TYPE V building using a brick veneer is still TYPE V. It must be extremely difficult deciphering once the building has already been built. On a call most buildings will have prior investigation though, right?

A normal outdoor strip mall for instance... TYPE III?

[stm4710]

Finally a good question from an explorer!

Brannigans books can be hard to stomach, I would suggest the IFSTA Building Construction related to fire service. Its more fightfighter/explorer friendly and breaks info down to more bite size pieices . It will also help give you a baseline knowledge to understand Mr. Brannigans books.

Good question.

[Golzy12]

Yes, I own a copy of Brannigan's book. It's a tough read for me but there is a lot of useful information packed into those pages.

So a TYPE V building using a brick veneer is still TYPE V. It must be extremely difficult deciphering once the building has already been built. On a call most buildings will have prior investigation though, right?

A normal outdoor strip mall for instance... TYPE III?

So a TYPE V building using a brick veneer is still TYPE V- thats right

On a call most buildings will have prior investigation though, right-not nescecerely(sp). Use your best judgementas a rule of thumb, if you dont know what type of building it is, assume it's the building that is more dangerous in this case a type III is less dangerous

[FireH2O]

An excellent question, indeed! However, the answer can be quite complex. The type of construction for a building is determined by the building code. To complicate matters, it depends on what building code is used (IBC, UBC, BOCA, NBC, NFPA 5000, or Standard). It also depends on what edition. The type of construction assigned at the time of construction may be different than the type that would be assigned under the current edition of the building code.

A “Type III” building may have an exterior wall that has a 0 Hr, 1 Hr, 2 Hr, or 4 Hr fire resistance rating. The exterior wall is required to be non-combustible. This means concrete, masonry, or steel. Some building codes allow fire retardant treated wood in the exterior wall. It depends on the building code in effect at the time of construction and whether it is a bearing or non-bearing wall. When you examine the exterior wall and see wood, it does not necessarily exclude Type III construction. Like I said, it’s complicated.

The occupancy of the building and the type of construction will dictate the allowable building area (sq.ft.). Increases in area are permitted for fire sprinklers and multi-stories. So, when you look at a building, consider the building area and occupancy. A 100,000 sq.ft. building will typically not be a Type V building. However, there are provisions for “unlimited area” buildings. Like I said, it’s complicated.

Terminology has changed. What was classified as a Type III-N building is now called a Type III-B building.

One way to determine the type of construction at the time of construction is to check with the building department. They should have files. If you’re lucky, they will have a street file containing information regarding every street address (with the possible exception of SFD’s). Make a list of the properties in which you are interested and go to the building department. This is pre-planning. Check the fire department street files as they will typically identify buildings with fire sprinkler systems, fire alarm systems, smoke control systems, occupancy permits such as high piled storage, etc.

From a fire suppression standpoint you are interested in how long a building will be structurally stable and whether the construction (as opposed to the contents) will be burning. Type I buildings are fire resistive. Type V-N or Type V-B buildings are combustible with little to no fire resistance. The types of construction in between Types I and V are generally in order of decreasing fire resistance, with a few possible exceptions.

Study the building code in effect in your jurisdiction. The International Code Congress (ICC) which promulgates the International Building Code offers seminars.

Terms such as “wood frame“, “ordinary”, “masonry”, “noncombustible“, “fire resistive” may be good descriptions of the types of construction but they are not consistent with the types of construction used by the building codes. For example, a “wood frame” building may have 4 Hr fire resistive walls while a “noncombustible” building may have unprotected steel studs and light weight open web trusses. From a firefighting viewpoint, which one is “better” from a structural standpoint? The “Wood frame” building is better than the “non-combustible” building (all else being equal, of course). Go figure!

I think the definition of “strip” mall may vary. I can’t remember ever seeing a Type I strip mall, although I have seen many Type I malls (one with an interior pedestrian walkway). I think of a “strip” mall as one where access to each store is directly from the outside and stores are arranged in a single line. I have seen these as Type II or Type V construction. If they are large in area, they may be Type II Fire Resistive (Type II-A) or Type V-1 Hr (Type V-A).

I hope this helps. It’s not everything, but it should be a good start. PATF1engineer provides valuable information, please re-read it.

Like I said, it’s complicated.

[Inspectorlady]

What is a Type III-N building? Doesn't the "N" represent "not fire rated"??

THANKS!