Construction type

[ELLEN09US]

Hello everyone,

Is the construction type for CMU wall and wood roof type III?

Thank you!

 

[Yikes]

ELLEN90US, see table 601
Type III construciton requires minimum 2 hour rated walls.
IIIA requires a one hour roof structure.
IIIB has a 0 hour roof.

A building with CMU walls and a wood roof can be made to qualify as as Type III.

Note that per 602.1.1, you can still decide to call it a lower type of construction (such as Type V) if you want, even though it is made out of CMU.

 

[ELLEN09US]

Thanks!
this is an existing building. I just want to put the info for the building.
So, it's type 5?

 

[classicT]

Thanks!
this is an existing building. I just want to put the info for the building.
So, it's type 5?

Get a copy of the CO from the AHJ.

 

[ELLEN09US]

Thanks!

 

[Builder Bob]

Depends -Type III B, if the exterior walls are two hour rated for bearing walls, then yes

If not - type V

 

[steveray]

Is it a heavy timber roof? Could be IIB....

 

[Paul Sweet]

8" block will usually give you a 2-hour fire rating (IBC 722.3.2)

NCMA TEK 02-01B will give you the equivalent thickness. Also see NCMA TEK 07-01C for fire rating info.
https://ncma.org/resource-results/?type=tek

 

[Builder Bob]

Assuming correctly grouted joints, reinforcement, and no holes polked thru - the problem we have is seismic, and until 2001 in SC, masonry was not constructed with seismic provisions - thus does not qualify.

 

[Paul Sweet]

Grout will increase the equivalent thickness, and thus the fire resistance.