Does anyone know of 1hr UL assmeblies for steel beams that are in a 1hr rated wood f-c assembly (L546 to be specific)? All SFRM, intumescent coating and even gyp surronds assemblies seem to have metal deck and concrete floor which L546 doesn't have.
-
Welcome to The Building Code Forum
Your premier resource for building code knowledge.
This forum remains free to the public thanks to the generous support of our Sawhorse Members and Corporate Sponsors. Their contributions help keep this community thriving and accessible.
Want enhanced access to expert discussions and exclusive features? Learn more about the benefits here.
Ready to upgrade? Log in and upgrade now.
1HR UL Assemblies for Steel Beam in Wood F-C Assembly
- Thread starter lee1079
- Start date
steveray
SAWHORSE
Does the beam need individual encasement? Or is being in the assembly enough?
Builder Bob
SAWHORSE
spot on Steve Ray...
I'm going by 2012 IBC 704.3. Do you know of code section telling individual encasement is not required/needed?
What section first says your situation requires the steel beams have to have one hour??
my250r11
REGISTERED
IMO if inside the assembly it is fine if outside needs to be encased in 1hr assembly.
steveray
SAWHORSE
IBC 714.2....Take a look...
mtlogcabin
SAWHORSE
Is the building sprinkled?
The footnote in the Table 601 provides an exception for VA buildings
d. An approved automatic sprinkler system in accordance with Section 903.3.1.1 shall be allowed to be substituted for 1-hour fire-resistance-rated construction, provided such system is not otherwise required by other provisions of the code or used for an allowable area increase in accordance with Section 506.3 or an allowable height increase in accordance with Section 504.2. The 1-hour substitution for the fire resistance of exterior walls shall not be permitted.
Other wise encasement on all four sides may be required per 704.3 and 704.4
The footnote in the Table 601 provides an exception for VA buildings
d. An approved automatic sprinkler system in accordance with Section 903.3.1.1 shall be allowed to be substituted for 1-hour fire-resistance-rated construction, provided such system is not otherwise required by other provisions of the code or used for an allowable area increase in accordance with Section 506.3 or an allowable height increase in accordance with Section 504.2. The 1-hour substitution for the fire resistance of exterior walls shall not be permitted.
Other wise encasement on all four sides may be required per 704.3 and 704.4
It is I-1 occupancy so sprinkler is required "by other provisions of the code" and substitution would not be allowed I think.
steveray
SAWHORSE
Hunh...they moved and tweaked that since my 2003 codes, I will have to keep that in mind when we take the giant leap to 2012 in October...
Yikes
SAWHORSE
704.3 infers that if the beam is supporting only two floors or less, or a floor and roof or less, or a wall tow stories high or less, then individual encasement is NOT required. It can be protected by the typical membrane assembly of the one-hour floor-ceiling assembly.
704.3 Protection of the primary structural frame other than columns.
Members of the primary structural frame other than columns that are required to have protection to achieve a fire-resistance rating and support more than two floors or one floor and roof, or support a load-bearing wall or a nonload-bearing wall more than two stories high, shall be provided individual encasement protection by protecting them on all sides for the full length, including connections to other structural members, with materials having the required fire-resistance rating.
I see that we have not actually answered your original question, but instead we are trying to find ways to avoid individual encasement. Does anyone have commentary on the exception in italics above? I don't understand what it means.
704.3 Protection of the primary structural frame other than columns.
Members of the primary structural frame other than columns that are required to have protection to achieve a fire-resistance rating and support more than two floors or one floor and roof, or support a load-bearing wall or a nonload-bearing wall more than two stories high, shall be provided individual encasement protection by protecting them on all sides for the full length, including connections to other structural members, with materials having the required fire-resistance rating.
Exception: Individual encasement protection on all sides shall be permitted on all exposed sides provided the extent of protection is in accordance with the required fire-resistance rating, as determined in Section 703.
I see that we have not actually answered your original question, but instead we are trying to find ways to avoid individual encasement. Does anyone have commentary on the exception in italics above? I don't understand what it means.
I see them now and the beams don't fall into those conditions so no individual encasement protection is required. Here is the excerpt from the commentary although it doesn't explain Exception.
704.3 Protection of the primary structural frame other
than columns. Members of the primary structural frame
other than columns that are required to have protection to
achieve a fire-resistance rating and support more than two
floors or one floor and roof, or support a load-bearing wall or
a nonload-bearing wall more than two stories high, shall be
provided individual encasement protection by protecting
them on all sides for the full length, including connections to
other structural members, with materials having the required
fire-resistance rating.
Exception: Individual encasement protection on all sides
shall be permitted on all exposed sides provided the extent
of protection is in accordance with the required fire-resistance
rating, as determined in Section 703.
•:•All primary structural frames do not need to comply
with this section. Only those primary structural frame
members that are required to have a fire-resistance
rating and support more than two floors, more than
one floor and a roof, a bearing wall of any height or a
nonload-bearing wall more than two stories high, are
required to be protected by individual encasement.
Individual encasement, though not defined, is
attained by using tested design assemblies that provide
gypsum board applied directly to the member or
to studs that are directly attached to all sides of the
member, mastic and intumescent coatings, and
sprayed fire-resistant materials.
Individual encasement is required for the primary
structural frame members receiving tributary loads
from multiple levels in order to reduce the risk associated
with catastrophic failure. The risk represented by
structural collapse during a fire is significantly
increased in multistory buildings, since the occupants
require additional time of egress and a single structural
element that supports multiple elements
requires more conservative protection methods.
Though the text states that the encasement must
be on all four sides of the structural member, the
FIRE AND SMOKE PROTECTION FEATURES
exception will allow tested assemblies that have the
encasement on only the exposed sides of a member.
Figure 704.3 is an example of individual encasement
protection.
Note that some structural members such as heavy
wood beams may not require any protection (encasement
or membrane) to attain a fire rating (see calculated
fire resistance, Section 722.1).
Maybe if one side is not exposed/ say against or almost against say a concrete wall, you do not have to worry about that one "non-exposed" side??