PDF - Ron Blank and Associates, Inc.

Course Sponsor:
California Expanded
Metal Company
Dynamic and Static Head-of-Wall
Joint Fire Protection
An American Institute of Architects (AIA)
Continuing Education Program
Credit for this course is 1 AIA HSW CE Hour
Course number: cem05d
© Ron Blank & Associates, Inc. 2011
263 North Covina Lane
City of Industry, CA 91744
Phone: (626) 506-3881
E-mail:
[email protected]
Web:
www.cemcosteel.com
An American Institute of Architects (AIA)
Continuing Education Program
Approved Promotional Statement:
• Ron Blank & Associates, Inc. is a registered provider with The American
Institute of Architects Continuing Education System. Credit earned upon
completion of this program will be reported to CES Records for AIA
members. Certificates of Completion are available for all course
participants upon completion of the course conclusion quiz with +80%.
Please view the following slide for more information on Certificates of
Completion through RBA
•
This program is registered with the AIA/CES for continuing professional
education. As such, it does not include content that may be deemed or
construed to be an approval or endorsement by the AIA or Ron Blank &
Associates, Inc. of any material of construction or any method or manner
of handling, using, distributing, or dealing in any material or product.
An American Institute of Architects (AIA)
Continuing Education Program
Course Format: This is a structured, web-based, self study course
with a final exam.
• Course Credit: 1 AIA Health Safety & Welfare (HSW) CE Hour
• Completion Certificate: A confirmation is sent to you by email and
you can print one upon successful completion of a course or from
your RonBlank.com transcript. If you have any difficulties printing or
receiving your Certificate please send requests to
[email protected]
•
•
Design professionals, please remember to print or save your
certificate of completion after successfully completing a course
conclusion quiz. Email confirmations will be sent to the email
address you have provided in your RonBlank.com account.
Course Description
Through an evaluation on head-of-wall assemblies, as well as
the UL standards for approval, the design professional will have
a better understanding of the components involved with each
application. In addition, we will review what design
professionals should consider when specifying protection of
dynamic or static head-of-wall joints.
Learning Objectives
By completing this course, the design professional will be able to:
• Describe what a Head-of-Wall joint is and what constitutes a Headof-Wall assembly
• Describe a UL listed assembly
• List four standards used to determine UL 2079 approval
• Explain the deflection capacity of joint treatments
• Explain hourly ratings of joint treatments
• Describe what comprises the L-rating of joint treatments
• Compare and contrast joint treatment types and list the
advantages/disadvantages of each
• Describe shaft-wall assemblies
• Explain what Architects, Engineers, and Specification professionals
should consider when specifying protection of dynamic or static
Head-of-Wall joints
What is a Head-of-Wall Joint?
The distance between the top of the drywall and the bottom of
the overhead structure
Joint
Head-of-Wall Joint/Gap
•
•
•
The joint (based on amount of deflection required) is designed
and constructed to allow for vertical movement (allowing the
wall to move independent of the structure) due to forces such
as Live/Dead loading, thermal expansion/contraction, wind
sway, or seismic movements.
The Head-of-Wall joint allows vertical movement without
damaging the wall or drywall.
The drywall is the fire protection component and it’s key that
it’s not damaged/cracked.
Types Of Overhead Structures
Fluted Pan Deck
Flat Concrete
Types of Overhead Structures:
Fluted Pan Deck
Fluted pan deck includes
either floor or roof pan deck
assemblies varying in flute
size, height, and
configuration
Types of Overhead Structures:
Concrete Deck
Concrete decks include
post-tension slabs,
poured in place concrete,
and precast concrete
units - any overhead
consisting of a concrete
surface having a flat
surface area
Types of Overhead Structures:
Structural Steel Support
•
Structural steel supports include IBeams, tube steel beams, and open
web trusses where a wall is aligned
underneath a structural steel support
•
Coated/fireproofing around I-Beam
Types of Overhead Structures:
Wallboard Ceiling
Wallboard Ceiling - walls that attached to wallboard ceilings
Types of Overhead Structures:
Cantilever Under Beam
Cantilever Under Beam - walls that attach to Z-furring
cantilevered off steel I-beams
Typical Top Of Wall Deflection Systems:
“T” shaped “shoulder” track
“T” shaped track that creates a
shoulder which allows for
attachment of drywall rips aligned
with the exterior surface of the wall
to protect the head of wall gap
Shoulder Track
Typical Top Of Wall Deflection Systems:
U-shaped filled track
U-shaped track which
incorporates the use of plastic
bags and fire proofing fill in a
composite assembly
U-Shaped Track
Composite Deflection Track with
Intumescent
•
Composite deflection track with
intumescent material factory installed along
the outer web of the track to create a fie,
smoke and sound gasket when installed
against the overhead structure.
•
In a fire the intumescent material will begin
to expand at 375 degrees and seal off the
deflection gap between the edge of the
drywall and the overhead concrete deck
Composite Steel Angle with Intumescent
•
The composite steel angle with
intumescent can eliminate
substantial time and labor due to
the fact that it does not require any
fire caulking or fire sprays over the
mineral wool
•
This systems provides
up to 2” of 100%
unencumbered
movement
Slotted Track/Stuff and Spray Assembly
A lot of companies make slotted track and it is
incorporated in various head-of-wall deflection
and fire stopping solutions. Mineral wool is
installed in the flute voids as well as in the
deflection gap between the edge of the drywall
and the bottom of the fluted pan deck. All of this
work can only be done once the drywall is
installed so that the fire spray can lap over the
mineral wool and onto the drywall.
What Information is
Contained in the Header of a
UL Listed Assembly?
What Information is Presented in the
Header Section of a UL Listing?
UL listing example:
Joint System
System No. HW-D-0577
February 05, 2010
Assembly Ratings — 1, 2 and 3 HR (See Items 2 and 3)
Nominal Joint Width — 1/2 in.
Class II and III Movement Capabilities — 100% Compression or
Extension
L Rating at Ambient — Less Than 1 CFM/Lin Ft
L Rating at 400°F — Less Than 1 CFM/Lin Ft
Dynamic or Static Designation
There are two type of Head of wall assemblies
HW-D-#### & HW-S-####
The “D” represents “dynamic” which means it has movement
capabilities
The “S” represents “static” which means there is NO
movement capabilities
Date of Last Revision of the Assembly
Dynamic Joint System
System No. HW-D - xxxx
February 05, 2010
Assembly Ratings — 1, 2 and 3 HR (See Items 2 and 3)
Nominal Joint Width — 1/2 in.
Class II and III Movement Capabilities — 100% Compression or
Extension
L Rating at Ambient — Less Than 1 CFM/Lin Ft
L Rating at 400°F — Less Than 1 CFM/Lin Ft
It is important to make sure you are using the most current UL report;
the date will indicate which version you are reading and the most
current reports will always be listed on the UL on-line directory
Hourly Rating of Assembly
Dynamic Joint System
System No. HW-D - xxxx
February 05, 2010
Assembly Ratings — 1, 2 and 3 HR (See Items 2 and 3)
Nominal Joint Width — 1/2 in.
Class II and III Movement Capabilities — 100% Compression or
Extension
L Rating at Ambient — Less Than 1 CFM/Lin Ft
L Rating at 400°F — Less Than 1 CFM/Lin Ft
Systems will range from 1 to 4 hour fire rating and these ratings
will be listed here.
Joint/Gap Width
Dynamic Joint System
System No. HW-D - xxxx
February 05, 2010
Assembly Ratings — 1, 2 and 3 HR (See Items 2 and 3)
Nominal Joint Width — 1/2 in.
Class II and III Movement Capabilities — 100% Compression or
Extension
L Rating at Ambient — Less Than 1 CFM/Lin Ft
L Rating at 400°F — Less Than 1 CFM/Lin Ft
The gap between top edge of
drywall and overhead structure.
Some of these numbers have a
range and some have a maximum
number listed.
Movement Capabilities
Dynamic Joint System
System No. HW-D - xxxx
February 05, 2010
Assembly Ratings — 1, 2 and 3 HR (See Items 2 and 3)
Nominal Joint Width — 1/2 in.
Class II and III Movement Capabilities — 100% Compression or
Extension
L Rating at Ambient — Less Than 1 CFM/Lin Ft
L Rating at 400°F — Less Than 1 CFM/Lin Ft
This is the test for movement capabilities, Class I (Thermal),
Class II (Wind Sway), and Class III (Seismic)
What Is The Dynamic Cycle Test?
The dynamic cycle test is when an entire assembly including the wall,
wall framing, sheathing, overhead, and joint materials are cycled to
determine movement capabilities before the air (smoke) leakage, fire,
and hose stream tests take place.
Three measurements are used to determine the class rating and
deflection capabilities of the assembly and joint materials
• Cyclical abilities of the joint materials (Cycles per minute before
failure)
• Nominal gap of the joint (Installed Distance)
• Movement Capabilities (Compression/Extension)
Three levels of cycle
• Level I = 1 cycle/min for 500 cycles (Thermal)
• Level II = 10 cycles/min for 500 cycles (Wind Sway)
• Level III = 30 cycles/min for 500 cycles (Seismic)
L-Rating (Smoke Passage)
Dynamic Joint System
System No. HW-D - xxxx
February 05, 2010
Assembly Ratings — 1, 2 and 3 HR (See Items 2 and 3)
Nominal Joint Width — 1/2 in.
Class II and III Movement Capabilities — 100% Compression or
Extension
L Rating at Ambient — Less Than 1 CFM/Lin Ft
L Rating at 400°F — Less Than 1 CFM/Lin Ft
L-Rating: The L-rating is the amount of air (or cold smoke) that can
leak through a penetration, and the number indicates the amount of
air in cubic feet per minute (CFM)
The L-Rating is tested in both ambient (room temperature) and an
elevated 400°F environments. The ambient test measures any air
leakage that might contain cold smoke before the actual fire.
L- Rating ( Air Leakage)
•
Measurement on non-fire exposed assembly of the air leakage rate
through a fire-stop system or fire-resistive joint system, tested under
a differential pressure of 0.30 inches of water column (75 Pa) at both
75 and 400°F. The rate is expressed as a volumetric flow rate in units
of cfm/lft
•
Assembly is cycled to level listed on individual listings
•
Assembly is then opened to max. capable opening based on
movement ratings
•
Leakage measured at ambient (room temperature or 75 deg
Fahrenheit
•
Leakage measured at elevated temperature of 400 deg F
•
Rating calculated as cfm/lft (cubic feet per minute/ lineal feet of joint)
How Fast Does Smoke Travel?
Consider this:
•
A square room 20 ft x 20 ft x 20 ft has a pencil hole between
compartments.
•
How long will it take for the smoke to fill the room to a
thickness such that you cannot see your hands 18 inches in
front of you?
20 ft x 20 ft x 20 ft room
Pencil Hole
3 minutes
40 seconds
IBC 2009 – 713.6 Fire-resistant Joint
Systems in Smoke Barriers
Standard as of 2009
Fire-resistant joint systems in smoke barriers shall be tested in
accordance with the requirements of UL 2079 for air leakage.
The air leakage rate of the joint shall not exceed 5.0 CFM per
lineal foot (0.00775 m3/slm) of joint at .30 inch (7.47 Pa) of water
for both the ambient temperature and elevated
temperature tests.
Prior to 2006 there was not a measurable rating
defined in the code bodies. Simply defined as
a “non-direct passage of smoke.”
The standard was originally set in 2006 by IBC
based on UL2079 “L” rating tests.
From the National Fire Protection
Association (NFPA)
¾ of all fire deaths are caused by smoke inhalation
57% of all people killed in fire are not in the room of the fire
origin
• 47% of survivors caught in a fire could not see more than 12
feet
• Smoke travels 120-420 feet per minute under fire conditions
•
•
Four Standards Used to
Determine UL 2079 Approval
UL 2079 Standard Tests for Fire
Resistance of Building Joint Systems
•
Four measured standards for certification
1)
2)
3)
4)
•
Cyclical Testing (Movement) – how far it can move and how often
Flame passage (F-rating) – determine if flame can pass through
Thermal passage (T-rating) – heat passage, it can’t exceed 425 degrees
…when cotton ignites, paper starts to burn.
Hose Stream (H-rating) – 5 minutes to get it from the oven to the
stand for rapid testing. No direct stream.
Additional rating
1)
Leakage rating (L-rating)
Nominal (Installed) Gap And Movement
Capabilities
•
•
Movement capabilities are expressed as a percentage of the
nominal gap distance that joint materials can move during
compression and extension at a specified level of cycle without
adversely affecting the protection provided by the joint
materials.
Any material (caulk, mineral wool, etc.) that is applied in the
gap encumbers the movement. It is critical to pay close
attention to the UL Header to see if it indicates a percentage
of encumbrance that you
need to factor into your
deflection criteria and
decision related to what
assembly to use.
Example of Movement Calculation Table
for UL Listing 25% Capability
•
•
•
Assembly ratings – 1 and 2 Hr
Nominal Joint Width – 1 In. Max
Class II Movement Capabilities – 25% Compression or
Extension
(wind sway movement non-seismic conditions)
Nominal Joint
Width
25%
Compression
25%
Extension
Two Way =
Compress. +
Ext.
Compression
Only
½”
1/8”
1/8”
¼”
1/8”
1”
¼”
¼”
½”
¼”
2”
½”
½”
1”
½”
4”
1”
1”
2”
1”
The bottom two rows do not apply to encumbered systems because
the joint is to wide; it is there to show how wide the gap would have
to be to get 1” and 2” overall movement.
Example of Movement Calculation Table
for UL Listing 100% Capability
•
•
•
•
•
Assembly Rating – 1 and 2 Hr
L Rating at Ambient – Less than 1 CFM/Lin Ft
L Rating at 400°F – Less than 1 CFM/Lin Ft
Nominal Joint Width – ½ to 1 In.
Class II and III Movement Capabilities – 100% Compression or
Extension (wind sway and seismic movement)
Nominal
Joint Width
100%
Compression
100%
Extension
Two Way =
Compress. +
Ext.
Compression
Only
½”
½”
½”
1”
½”
¾”
¾”
¼”
1”*
¾”
1”
1”
1”
2”
1”
2”
2”
---
---
2”
F & T Rating (Burn Test)
•
After cycling of assembly, the Head-of-Wall joint is opened to
the maximum allowable joint distance based on the cycle test
•
Entire assembly subjected to fire measuring, the thermal
passage of heat, and restriction of flame through the assembly
•
Maximum allowable rise in temperature on unexposed side of
wall/wall sheathing, fire stop materials, and joint materials is
350°F above ambient (75°F) = 425°F
•
Assembly and joint materials must restrict the passage of any
flame or fire through to unexposed side to meet test criteria
Burn Test (F-Rating)
The Head-of-Wall Assembly is subjected to an 1800 degree oven.
This particular wall assembly has already burned for 2-hours.
H – Rating (Hose Stream)
Assembly removed from oven and subjected to a fire hose stream test
Water applied across entire assembly at 35 psi for approx 30 seconds
(joint testing) from straight nozzle fire hose
• Test the effects of rapid cooling
• Measure performance of assembly to restrict any direct stream of
water from penetrating through the assembly out the unexposed
side
• Observe all materials including mineral wool or fire proofing in deck
flutes to avoid dislodging of materials
•





Mineral wool in flutes
Fire proofing in flutes
Wall/Wall Sheathing on unexposed side
Fire resistive joint materials
Studs
Joint Treatment Types and the
Advantages/Disadvantages
of Each
Head-of-Wall Joint
Protection Systems
Commonly used materials to protect head of wall joints
providing a rated joint in wall partitions:
•
•
•
•
Caulk/spray
Drywall
Fire proofing
Steel intumescent fire stop
Joint
Encumbered Systems
•
•
Encumbered systems rely on adhesive strength and mastic to
fill in the Head-of-Wall joint
When the Head-of-Wall joint is filled in with fire resistant
material, the potential movement is limited to a percentage of
the joint size
Caulks/Sprays
•
•
Fire rated caulks and sprays typically have intumescent and
elastomeric properties that allow for some range of elongation
and compression
These products are applied in uncured “wet” state and can be
used in the Head-of-Wall gap or applied over a backing
material such as mineral wool or foam backing rod
Caulks/Sprays
Advantages
• Many brand formulations to choose from
• Elastomeric properties allow for some amount of movement
(see manufacturer’s recommendation)
• Aids in retention of flute fill materials
Disadvantages
• Encumbered movement typically limited to ½” or less of joint
width
• Quality of installation versus UL design
• Installation typically post MEP (labor to workaround
obstructions)
• Difficult to inspect proper dosage
•
•
Proper dosage
Can be more expensive then other systems
Caulks/Sprays
Avoid Three Sided Adhesion
“bond breaker” tape or backer rod is required to be installed
against the leg of the track prior to installing sealant to prevent
three sided adhesion
Caulk/Spray Disadvantages
Horizontal stress cracks from movement
•
Adhesive failure
Sealant manufacturers will typically call out for a surface free of water, dirt,
oil, frost, etc.
•
Cohesive failure
Dries, cracks, pulls apart when extended
•
Substrate failure
Pulling the fireproofing
(around coated decks, beams)
Drywall “Rips”
Drywall rips can be installed in front of Head-of-Wall gaps to
provide fire protection of equivalent ratings as the wall
assembly
• Can be attached to common cold formed steel angle via
fasteners
• Drywall rip/angle assembly can then be positively attached to
structure with typical steel fasteners
• Typically requires similar amount and profiles of gypsum
panels used to achieve rating of wall assembly
•
Drywall “Rips”
Drywall “Rips”
•
Advantages
 Gypsum materials are readily available
 Cold formed steel angles typically available
 Positive attachment of the Drywall rip/Angle assembly to the structure
•
Disadvantages
 Labor required to “rip” or cut down to size gypsum sheets
 Labor to install gypsum to cold formed steel angles typically 8” O/C with
fasteners
 Still require installation of and additional materials to hold mineral wool
in flutes above the wall assembly
“Shoulder” Track Profile and Systems
Utilizing Drywall Rips
•
•
Shoulder track profile which provides a “shoulder” to attach
drywall rips covering the Head-of-Wall gap
Multiple pieces of metal profiles or drywall rips installed to
create a “shoulder” for drywall rip attachment in front for
Head-of-Wall gaps
“Shoulder” Track Profile and
Systems Utilizing Drywall Rips
“Shoulder” Track
•
Advantages
 Drywall materials readily available and can be cut down to be used for
“rips” in front of Head-of-Wall gap
 Allow for large amounts of uncompromised deflection
•
Disadvantages
 Installation of differing wall widths, fire ratings, and deflection
requirements require multiple track or material profiles
 Labor to install drywall rips with a screw attachment every 3” OC both
sides (two rips per side for 2 hr rating)
 Requires caulk to be installed between the drywall rips and contour of
overhead structure
Composite Steel Angle with Intumescent
An example of how the Composite Steel Angle with Intumescent
is installed once the wall is “topped out” early in the
construction process. The same framer can build the wall and
install the fire protection in one application without installing
drywall. Drywall is always prone to
water damages/mold if the roof is
not installed prior to the
drywall installation.
DEFLECTION DRIFT
ANGLE – DDA
(BOTH SIDES)
SLOTTED
TRACK
Composite Steel Angle with Intumescent
Provides unencumbered movement
• Can be installed before MEP’s
• No fasteners required
• Installed with approved solid/slotted leg tracks
• Eliminates materials and labor to “castle cut” or rip drywall for
use to protect joints or flute
• Spray can be applied before drywall is installed
• Provides higher levels of movement then traditional stuff and
spray systems
• UL joint system for both standard walls and shaft walls
•
Composite Deflection Track
with Intumescent
Addresses deflection and fire stopping in a single step
installation process. The above photos show the composite
deflection track before and after a fire/burn test. As shown in the
“after fire” photo the intumescent completely fills the head of
wall joint with a hard char material that
blocks smoke and fire passage.
Before fire
After fire
Composite Deflection Track with
Intumescent
•
•
•
•
•
•
•
•
•
•
•
•
Superior unencumbered movement
Eliminates reliance of adhesion and bond strength caulk
“Floating Ceiling” (reveal) design with fire-rated wall
No fatigue for the life of the assembly
Faster installation; saves time, and labor
UL Listed for 1-2 hour rating with single profile
Seismic listing and ratings for Level 3
Quality assurance of “factory metered” dosage
Best possible L-Rating of less than 1 CFM
STC ratings tested greater than acoustic sealants
Cured intumescent is odor-free
Unaffected by wet, freezing, humid, hot (below 300 F) conditions
Shaft-Wall Assemblies
What are Shaft Wall Assemblies?
•
•
•
Shaft wall assemblies are walls that can be built from one side
of the wall
Shaft walls assemblies are typically utilized in elevator shafts,
stairwells, and mechanical rooms
As with standard walls, shaft walls also require movement
capabilities
Shaft Wall Assemblies
•
•
•
Shaft wall joint systems are listed in the UL online directory
Shaft wall joint systems are tested the same way standard
walls are tested according to UL 2079
3rd party tested Shaft Wall assemblies with movement are
very limited in types of assemblies
“Shoulder Track” profile Shaft Wall
Assembly
This shaft wall assembly
requires access from
both sides of the wall
which defeats the
propose of a shaft wall
which is supposed to be
able to have the ability
to built from one side of
the wall
“Shoulder Track”
Shaft Wall Assembly
•
Advantages
 Superior unencumbered movement
 3rd Party tested and certified system
•
Disadvantages
 Requires access to both sides of the wall
 High labor and material costs
Slotted Track/Fire Caulking Assembly
Head of wall joints with dynamic movement for shaft wall joint
systems now require a secondary application fire sealant above
the shaft liner to the inside web of the track.
Slotted Track/Fire
Caulking Assembly
Advantages:
• Slotted track and fire caulking are readily available.
• On solid concrete decks walls can be built from one side.
Disadvantages:
• Provides minimum movement.
• On fluted pan decks fire spray needs to be sprayed on both
sides of the wall.
• Most assemblies are very difficult to install and inspect.
• Fire sealant needs to be applied to the inside wall cavity above
the shaft liner which is difficult to access and properly install.
Composite Deflection Track with
Intumescent for Shaft Wall
Composite deflection J-track has factory applied intumescent
tape and is sent out to the project ready to install. 4 psf mineral
wool is than field installed to ensure fire, smoke, or sound is able
to pass through head-of-wall deflection joint.
J-TRACK
Composite Deflection Track with
Intumescent for Shaft Wall
Advantages
No fire caulking required
• Provides unencumbered movement
• 3rd party tested and certified
• Can be built from one side of the wall
•
Disadvantages
•
Additional mineral wool needs to be installed into the web of the
track
Considerations When
Specifying Protection of
Dynamic or Static Head-ofWall Joints
What to Look for Choosing a
Head-of-Wall Assembly
How many UL systems does the manufacture offer?
Do the manufacturer’s UL assemblies cover both standard wall
and shaft walls?
• Will the performance of the assembly meet the movement
requirement?
• What is the overall cost and long-term maintenance of the
system?
•
•
Design Considerations of Dynamic Joint
Protection in Fire Rated Assemblies
Good design practices take into consideration a number of
factors when specifying dynamic joint protection:
•
•
•
•
•
•
•
•
•
•
Deflection requirements
Cyclical movement
Thermal protection
Air leakage
Fatigue of joint systems
Attachment of joint systems (structural requirements)
Environmental forces / Geographic location (zones)
Post construction movement a structure
Live load and frequency of movement
Dead load
Joint Material Properties
In specifying joint protection several factors to also consider:
The attachment or adhesion of the fire stop materials
• The elasticity (compression and extension capabilities) of the
joint materials
• Longevity/Environmental conditions affecting materials
•
Sustainability?
Will the Firestopping Material Contribute to LEED Materials &
Resources – “Construction Waste Management”
• Intent: Divert construction and demolition debris from disposal in
landfills and incinerators. Redirect recyclable recovered resources
back to the manufacturing process. Redirect reusable materials to
appropriate sites
Does it Contribute to LEED Materials & Resources – “Recycled
Content”
• Intent: Increase demand for building products that incorporate
recycled content materials, thereby reducing impacts resulting from
extraction and processing of virgin materials
Course Summary
Now, the design professional will be able to:
• Describe what a Head-of-Wall joint is and what constitutes a Headof-Wall assembly
• Describe a UL listed assembly
• List four standards used to determine UL 2079 approval
• Explain the deflection capacity of joint treatments
• Explain hourly ratings of joint treatments
• Describe what comprises the L-rating of joint treatments
• Compare and contrast joint treatment types and list the
advantages/disadvantages of each
• Describe shaft-wall assemblies
• Explain what Architects, Engineers, and Specification professionals
should consider when specifying protection of dynamic or static
Head-of-Wall joints
Course Sponsor:
California Expanded
Metal Company
Dynamic and Static Head-of-Wall
Joint Fire Protection
An American Institute of Architects (AIA)
Continuing Education Program
Credit for this course is 1 AIA HSW CE Hour
Course number: cem05d
© Ron Blank & Associates, Inc. 2011
263 North Covina Lane
City of Industry, CA 91744
Phone: (626) 506-3881
E-mail:
[email protected]
Web:
www.cemcosteel.com