Fireblocking and draftstopping is contained in Section 717 "Concealed Spaces" of the
International Building Code. Tests conducted by Omega Point Laboratories demonstrated
that cellulose insulation performed better than wood as a fire stop.
The following is contained in the 2003 INTERNATIONAL BUILDING CODE (IBC) and 2004
SUPPLEMENTS. Contact your architect, engineer, or local code official concerning
your specific project application.
SECTION 717: CONCEALED SPACES
Fireblocking and draftstopping shall be installed in combustible concealed locations in
accordance with this section. Fire blocking shall comply with Section 717.2. Draftstopping
shall comply with Sections 717.3 and 717.4 respectively. The permitted use of combustible
materials in concealed spaces of Type I or II construction shall be limited to the
applications indicated in Section 717.5.
717.2 Fireblocking In combustible construction
Fireblocking shall be installed to cut off concealed draft openings (both vertical and
horizontal) and shall form an effective barrier between floors, between a top story and
a floor or attic space. Fireblocking shall be installed in the locations specified in
Section 717.2.2 through 717.2.7
What materials can be considered fireblocking and what is the criteria for a
fireblocking material? There is no specific test criteria for a fireblocking material
however 717.2.1 states the following about fireblocking materials.
717.2.1 Fireblocking materials
Fireblocking shall consist of 2-inch nominal lumber or two thicknesses of 1-inch nominal
lumber with broken lap joints or one thickness of 0.719-inch wood structural panel with
joints backed by 0.719-inch wood structural panel or one thickness of 0.75-inch particleboard
with joints backed by 0.75-inch particleboard. Gypsum board, cement fiber board, batts, or
blankets of mineral wool or glass fiber or other approved materials installed in such a
manner as to be securely retained in place shall be permitted as an acceptable fireblock.
Since there is no test criteria, how are "other approved materials" determined. Logic
dictates "other approved materials" would need to have the same fire endurance as the any
of the materials listed above. Since 2-inch nominal lumber is a common construction fireblock
material, cellulose insulation was compared to this lumber sample in the time-temperature
curve used in ASTM E119 to compare fire endurance.
The Cellulose Insulation Manufacturers Association (CIMA) contracted with Omega Point
Laboratories to compare the fireblocking abilities of spray-applied cellulose insulation
versus spruce-pine-fir wood fireblocking. Small-scale wood stud wall sections were
constructed and divided into three sections. The fireblocking materials under evaluation
were: 1) two layers of 1 x 4 lumber, 2) spray-applied cellulose insulation at a depth of
14-1/2", and 3) one layer of 2 x 4 or 2 x 6 lumber. The wall sections were mounted in slots
in a horizontal test frame, and the ASTM E119 time/temperature curve was followed for a period
of 60 minutes. The maximum furnace temperature under this test was 1,721 degrees F. The
temperature on the unexposed surface (opposite the furnace heat) of the cellulose insulation
remained well below those on the unexposed surface of the wood fireblocking throughout the test.
The detailed test data is contained in Omega Points Laboratories Project Report 10694-111638
dated August 28,2002.
After 1-hour cellulose insulation kept the temperature in the area above the heat source
well below the lumber that is defined in the IBC as a fireblock material. This is another
demonstration of the fire resistance of cellulose insulation compared to conventional
Cellulose....it's naturally better insulation
The following pages contain all Cellulose Insulation fire related material.
R-TEK Insulation is your insulation contractor of choice.
If you have any questions regarding commercial or home insulation please do not hesitate
to call us at: (330) 753-8394. We will be more than happy to assist you.