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eLibrary > FEMA 424 - Design Guide for Improving School Safety in Earthquakes, Floods, and High Winds >

FEMA 424 - Design Guide for Improving School Safety in Earthquakes, Floods, and High Winds, 2004

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fema424_toc_.pdf [Go to Page]
1.1 INTRODUCTION
1.2 SCHOOL CONSTRUCTION: THE NATIONAL PICTURE
1.3 PAST SCHOOL DESIGN
1.4 PRESENT SCHOOL DESIGN
1.5 FUTURE SCHOOL DESIGN
1.6 THE DESIGN AND CONSTRUCTION PROCESS
1.6 SCHOOL DESIGN AND CONSTRUCTION [Go to Page]
1.6.1 Structure
1.6.2 Nonstructural Systems and Components
2.1 INTRODUCTION
2.2 DEFINITIONS OF PERFORMANCE-BASED DESIGN
2.3 THE PRESCRIPTIVE APPROACH TO CODES
2.4 THE PERFORMANCE-BASED APPROACH
2.5 HAZARD, RISK AND PROBABILITY
2.6 ACCEPTABLE RISK AND PERFORMANCE LEVELS
2.7 Correlation between Performance Groups and Tolerated Levels of Damage
2.8 Roles of Designers, Code Officials, and THE School District
2.9 CHANGES TO A BUILDING DESIGNED FOR PERFORMANCE
2.10 Current Performance-Based Codes
2.11 The O&M Manual AND THE Occupants’ handbook
2.12 PERFORMANCE-BASED DESIGN FOR NATURAL HAZARDS [Go to Page]
2.12.1 Performance-based Seismic Design
2.11.2 Performance-based Flood Design
2.11.3 Performance-based High Wind and Tornado Design
3.1 INTRODUCTION
3.2 THE HAZARDS COMPARED [Go to Page]
3.2.1 Location: Where are They?
3.2.2 Warning: How Much Time is There?
3.2.3 Frequency: How Likely are They to Occur?
3.2.4 Risk: How Dangerous are They?
3.2.5 Cost: How Much Damage Will They Cause?
3.3 Comparative losses
3.4 Fire and Life Safety
3.5 HAZARD PROTECTION METHODS COMPARISONS: REINFORCEMENTS AND CONFLICTS
4.1 Introduction
4.2 THE NATURE AND PROBABILITY OF EARTHQUAKES [Go to Page]
4.2.1 Earthquakes and Other Geologic Hazards
4.2.2 Earthquakes: A National Problem
4.2.3 Determination of Local Earthquake Hazards
4.3 VULNERABILITY: WHAT EARTHQUAKES CAN DO TO SCHOOLS [Go to Page]
4.3.1 Vulnerability of Schools
4.3.2 Earthquake Damage to Schools
4.3.3 Significant School Damage in Recent U.S. Earthquakes
4.3.4 Consequences: Casualties, Financial Loss, and Operational Disruption
4.4 SCOPE, EFFECTIVENESS, AND LIMITATIONS OF CODES [Go to Page]
4.4.1 The Background of Seismic Codes
4.4.2 Seismic Codes and Schools
4.4.3 The Effectiveness of Seismic Codes
4.5 EVALUATING EXISTING SCHOOLS FOR SEISMIC RISK AND SPECIFIC RISK REDUCTION METHODS [Go to Page]
4.5.1 Rapid Visual Screening
4.5.2 Systems Checklist for School Seismic Safety Evaluation
4.5.3 The NEHRP Handbook for the Seismic Evaluation of Existing Buildings (FEMA 178/310)
4.6 EARTHQUAKE RISK REDUCTION METHODS [Go to Page]
4.6.1 Risk Reduction for New Schools
4.6.2 Risk Reduction for Existing Schools
4.7 THE SCHOOL AS A POST-EARTHQUAKE SHELTER
4.8 REFERENCES AND SOURCES OF ADDITIONAL INFORMATION
4.9 GLOSSARY OF EARTHQUAKE TERMS
5.1 INTRODUCTION
5.2 NATURE AND PROBABILITY OF FLOODS [Go to Page]
5.2.1 Characteristics of Flooding
5.2.2 Probability of Occurrence
5.2.3 Hazard Identification and Flood Data
5.3 SCOPE, EFFECTIVENESS, AND LIMITATIONS OF BUILDING CODES AND FLOODPLAIN MANAGEMENT REQUIREMENTS [Go to Page]
5.3.1 Overview of the NFIP
5.3.2 Summary of the NFIP Minimum Requirements
5.3.3 Model Building Codes and Standards
5.4 RISK REDUCTION: AVOIDING FLOOD HAZARDS [Go to Page]
5.4.1 Benefits/Costs: Determining Acceptable Risk
5.4.2 Identifying Flood Hazards at School Sites
5.5 RISK REDUCTION: FLOOD-RESISTANT NEW SCHOOLS [Go to Page]
5.5.1 Site Modifications
5.5.2 Elevation Considerations
5.5.3 Flood-proofing Considerations
5.5.4 Accessory Structures
5.5.5 Utility Installations
5.5.6 Potable Water and Wastewater Systems
5.5.7 Storage Tank Installations
5.5.8 Access Roads
5.6 VULNERABILITY: WHAT FLOODS CAN DO TO EXISTING SCHOOLS [Go to Page]
5.6.1 Site Damage
5.6.2 Structural Damage
5.6.3 Saturation Damage
5.6.4 Utility System Damage
5.6.5 Contents Damage
5.7 RISK REDUCTION: PROTECTING EXISTING SCHOOLS [Go to Page]
5.7.1 Site Modifications
5.7.2 Additions
5.7.3 Repairs, Renovations, and Upgrades
5.7.4 Retrofit Dry Flood-proofing
5.7.5 Utility Installations
5.7.6 Potable Water and Wastewater Systems
5.7.7 Other Damage Reduction Measures
5.7.8 Emergency Measures
5.8 THE SCHOOL AS AN EMERGENCY SHELTER
5.9 REFERENCES AND SOURCES OF ADDITIONAL INFORMATION
5.10 GLOSSARY OF FLOOD PROTECTION TERMS
6.1 INTRODUCTION
6.2 THE NATURE AND PROBABILITY OF HIGH WINDS [Go to Page]
6.2.1 Wind/Building Interactions
6.2.2 Probability of Occurrence
6.3 VULNERABILITY: WHAT WIND CAN DO TO SCHOOLS
6.4 SCOPE, EFFECTIVENESS, AND LIMITATIONS OF BUILDING CODES [Go to Page]
6.4.1 Scope
6.4.2 Effectiveness
6.4.3 Limitations
6.5 PRIORITIES, COSTS, AND BENEFITS: NEW SCHOOLS [Go to Page]
6.5.1 Priorities
6.5.2 Cost, Budgeting, and Benefits
6.6 PRIORITIES, COSTS, AND BENEFITS: EXISTING SCHOOLS [Go to Page]
6.6.1 Priorities
6.6.2 Cost, Budgeting, and Benefits
6.7 EVALUATING SCHOOLS FOR RISK FROM HIGH WINDS [Go to Page]
6.7.1 Tornadoes
6.7.2 Portable Classrooms
6.8 RISK REDUCTION DESIGN METHODS [Go to Page]
6.8.1 Siting
6.8.2 School Design
6.8.3 Peer Review
6.8.4 Construction Contract Administration
6.8.5 Post-occupancy Inspections, Periodic Maintenance, Repair, and Replacement
6.9 STRUCTURAL SYSTEMS
6.10 EXTERIOR DOORS [Go to Page]
6.10.1 Loads and Resistance
6.10.2 Durability
6.10.3 Exit Door Hardware
6.10.4 Water Infiltration
6.10.5 Weatherstripping
6.11 NON-LOAD BEARING WALLS, WALL COVERINGS, SOFFITS, and Underside of Elevated Floors [Go to Page]
6.11.1 Loads and Resistance
6.11.2 Durability
6.11.3 Wall Coverings
6.11.4 Underside of Elevated Floors
6.12 ROOF SYSTEMS
6.13 WINDOWS AND SKYLIGHTS [Go to Page]
6.13.1 Loads and Resistance
6.13.2 Durability
6.13.3 Water Infiltration
6.14 EXTERIOR-MOUNTED MECHANICAL, ELECTRICAL, AND COMMUNICATIONS EQUIPMENT [Go to Page]
6.14.1 Loads and Attachment
6.14.2 Equipment Strength
6.14.3 Durability
6.15 SCHOOLS LOCATED IN HURRICANE-PRONE REGIONS [Go to Page]
6.15.1 Design Loads
6.15.2 Structural Systems
6.15.3 Exterior Doors
6.15.4 Non-load Bearing Walls, Wall Coverings, and Soffits
6.15.5 Roof Systems
6.15.7 Emergency Power
6.15.8 Construction Contract Administration
6.15.9 Periodic Inspections, Maintenance, and Repair
6.16 DESIGN FOR TORNADO SHELTERS
6.17 REMEDIAL WORK ON EXISTING SCHOOLS
6.18 REFERENCES AND SOURCES OF ADDITIONAL INFORMATION
Table 2-1: Performance Groups and Tolerated Levels of Damage
Table 2-2: Performance Groups and Tolerated Levels of Damage
Table 2-2: Seismic Expectations Checklist
Table 2-3: Damage Control and Building Performance Levels
Table 4-1: Known Historic (1568-1989) Earthquakes in 47 U.S. States
Table 4-2: School Seismic Safety Evaluation Checklist
Table 4-3: Roofing Maintenance and Repair/Re-Roofing
Table 5- 1: Flood Hazards at School Sites
Table 5-2: Characteristics of Existing School Buildings
Table 6-1: Summation of Risk Reduction Design Methods
Table 6-2: Summation of Design of Schools Used for Hurricane Shelters and/or for Emergency Response After a Storm
Table 6-3: Summation of Design for Tornado Shelters
Table 6-4: Summation of Remedial Work on Existing Schools
Figure 1-1 One-room schoolhouse, Christiana, DE, 1923
Figure 1-2 High school, New York City, 1929
Figure 1-3 Elementary school, Washington, DC, 1930 [Go to Page]
Figure 1-4 Typical finger plan school, 1940s. In California, the access hallways would be open to the air. The cross-section diagram shows the simple and effective day lighting and ventilation.
Figure 1-5 Compact courtyard plan, 1960s
Figure 1-6 Fountain Valley High School, Huntington Beach, CA, 1964 (330 students)
Figure 1-7 Open enclosure plan teaching area, with movable screens and storage, Rhode Island,1970
Figure 1-8 Typical modular classrooms, 1980s, still in use
Figure 1-9 Elementary school, Fairfield, PA, 1980s
Figure 1-10 Private high school, Palo Alto, CA, located in a remodeled industrial building. Note the exterior cross bracing; the building required extensive retrofitting to meet school seismic requirements.
Figure 1-11 West High School, Aurora, IL, 2000 [Go to Page]
Figure1-12 Elementary school, Oxnard, CA, 2000
Figure 1-13 The design and construction process flow chart [Go to Page]
Figure 2-1 Performance-based design approach flow chart
Figure 3-1 Peak accelerations (%g) with 10 percent probability of exceedance in 50 years. Color code shows %g for areas between contour lines. These values are used for seismic design.
Figure 3-2 Presidential Disaster Declarations for floods, January 1965 to November 2000. The incidence of declarations is shown by counties.
Figure 3-3 Presidential Disaster Declarations for hurricanes, January 1965 to November 2000. The incidence of declarations is shown by counties.
Figure 4-1 School, Anchorage, AK, 1964, severely damaged by earthquake-induced landslide.
Figure 4-2 Map of the continental United States that shows counties and probabilities of earthquakes of varying magnitude. [Go to Page]
Figure 4-3 Map showing older seismic zones in part of the United States, from the 1997 Uniform Building Code. The area in the box corresponds to the area in Figure 4-4.
Figure 4-4 Portion of an earthquake ground motion map used in the International Building Code 2003 that shows contours that identify regions of similar spectral response accelerations to be used for seismic design. Spectral response acceleration includes both ground
Figure 4-5 These maps compare the seismicity of the Southeast U.S. and California. Note the larger acceleration values for the latter, symbolized by the darker colors.
Figure 4-6 These maps show a comparison for the Southeast U.S. between the acceleration values for a 1-second (long) and a 0.2-second (short) building period.
Figure 4-7 Ductility [Go to Page]
Figure 4-8 Collapse of portion of nonductile concrete frame school structure, Helena, MT, 1935.
Figure 4-9 Modular classrooms pushed off their foundations; note stairs at left, Northridge, CA, 1994.
Figure 4-10 Fallen filing cabinets and shelves, Northridge, CA, 1994.
Figure 4-11 Fallen shop equipment, Coalinga, CA, 1983.
Figure 4-12 Fallen light fixtures, library, Coalinga, CA, 1983.
Figure 4-13 Fallen heavy lath and plaster ceiling across auditorium seating, Northridge, CA, 1994.
Figure 4-14 Damage to the John Muir School, Long Beach, CA, 1933.
Figure 4-15 Damage to shop building, Compton Junior High School, Long Beach, CA, 1933.
Figure 4-16 A dangerous passage way between two buildings, Polytechnic High School, Long Beach, CA, 1933.
Figure 4-17 A heavy corridor lintel ready to fall, Emerson School, Bakersfield, Kern County, CA, 1952.
Figure 4-18 Overturned shop equipment and failed light fixtures, Kern County, CA, 1952.
Figure 4-19 Destroyed exit corridor, Bakersfield, Kern County, CA, 1952.
Figure 4-20 Typical school damage, Helena, MT, 1935.
Figure 4-21 The student body president was killed here by falling brickwork, Seattle, WA, 1949.
Figure 4-22 Another dangerous entry collapse, Seattle, WA, 1949.
Figure 4-23 Collapse of roof over stage, Seattle, WA, 1949.
Figure 4-24 Damage to library shelving, Seattle, WA, 1949.
Figure 4-25 Severe structural damage to the West Anchorage High School, Anchorage, AK, 1964.
Figure 4-26 Brittle failure at nonductile concrete column, West Anchorage High School, 1964.
Figure 4-30 Example of rapid visual screening information form.
Figure 4-31 The structural and nonstructural components. The upper graphic shows the building structure. The lower graphic shows the addition of the main nonstructural components.
Figure 4-32 Suspended ceiling and light fixture bracing and support. [Go to Page]
Figure 4-33 Bracing tall shelving to the structure.
Figure 4-34 Connection of nonstructural masonry wall to structure to permit independent movement.
Figure 4-35 Bracing for existing unreinforced masonry parapet wall.
Figure 4-36 Design strategies for seismic retrofit of existing buildings.
Figure 4-37 Retrofit of B.F. Day Elementary School, Seattle, WA.
Figure 4-38 Sections and plans of the B.F. Day School: existing at bottom, retrofitted at top. Note that the retrofit has also opened up the basement and first floor to provide large spaces suitable for today’s educational needs.
Figure 5-1 The riverine floodplain
Figure 5-2 The coastal floodplain
Figure 5-3 Riverine flood hazard zones
Figure 5-4 Definition sketch – flood elevations
Figure 5-5 A high school in Bloomsburg, PA, elevated on fill
Figure 5-6 Elementary school in Jefferson County, OH, elevated on columns
Figure 5-7 Hydrostatic force diagram [Go to Page]
Figure 5-8 Fractured concrete basement floor, Gurnee, IL, 1986
Figure 5-9 Damaged walls and cabinets, Peoria County, IL
Figure 5-10 Basement damage at a grade school in Gurnee, IL, 1986
Figure 5-11 Schematic of typical earthen levee and permanent floodwall
Figure 5-12 Masonry floodwall with multiple engin eered closures
Figure 5-13 Elevated electric transformer at an elementary school in Verret, LA
Figure 5-14 Elevated utilities behind an elementary school in Wrightsville Beach, NC
Figure 6-1 Hurricane-prone regions and special wind regions
Figure 6-2 Tornado occurrence in the United States based on historical data
Figure 6-3 Design wind speeds for community tornado shelters [Go to Page]
Figure 6-4 Schematic of wind-induced pressures on a building
Figure 6-5 Schematic of internal pressure condition when the dominant opening is in the windward wall
Figure 6-6 Schematic of internal pressure condition when the dominant opening is in the leeward wall
Figure 6-7 Relative roof uplift pressures as a function of roof geometry, roof slope, and location on roof, and relative positive and negative wall pressures as a function of location along the wall. Negative values indicate suction pressure acting upward from the ro
Figure 6-8 The aggregate ballast on this single-ply membrane roof was blown away in the vicinity of the corners of the wall projections at the window bays. The irregular wall surface created turbulence, which led to wind speed-up and loss of aggregate in the turbulen
Figure 6-9 The metal roof is over a stair tower. The irregularity created by the stair tower caused turbulence that resulted in wind speed-up. The built-up roof’s base flashing was pulled out from underneath the coping and caused a large area of the membrane to lift
Figure 6-10 This high school in northern Illinois was heavily damaged by a strong tornado. In this classroom wing, all of the exterior windows were broken, and virtually all of the cementitious wood-fiber deck panels were blown away. Much of the metal decking over the
Figure 6-11 A portion of the built-up membrane at this school lifted and peeled after the metal edge flashing lifted. The cast-in-place concrete deck kept a lot of water from entering the school. Virtually all of the loose aggregate blew off the roof and broke many wi
Figure 6-12 The outer panes of these windows were broken by aggregate from a built-up roof. The inner panes had several impact craters. In several of the adjacent windows, both the outer and inner panes were broken. The aggregate had a flight path in excess of 245 fee
Figure 6-13 The metal wall covering on this school was applied to plywood over metal studs. The metal stud wall collapsed in this area, but, in other areas, it was blown completely away. The CMU wall behind the studs did not appear to be damaged. This school was on th
Figure 6-14 The unreinforced CMU wall at this school collapsed during a storm that had wind speeds that were less than the design wind speed.
Figure 6-15 The roof and all the walls of a wing of this elementary school were blown away by a violent tornado.
Figure 6-16 This portable classroom was blown up against the main school building during a storm that had wind speeds that were less than the design wind speed. Depending upon the type of exterior wall, an impacting portable classroom may or may not cause wall collaps
Figure 6-17 This newly-constructed gymnasium had a structural metal roof panel (3-inch trapezoidal ribs at 24 inches on center) applied over metal purlins. The panels detached from their concealed clips. A massive quantity of water entered the school and buckled the w
Figure 6-18 A portion of the roof structure blew off of this school, and a portion of it collapsed into classrooms. Because of extensive water damage, a school such as this can be out of operation for a considerable period of time.
Figure 6-19 The HVAC unit in the parking lot in the photo’s lower right corner blew off the curb during a storm that had wind speeds that were less than the design wind speed. A substantial amount of water entered the building before a temporary covering could be plac
Figure 6-20 This figure illustrates load path continuity of the structural system. Members are sized to accommodate the design loads and connections are designed to transfer uplift loads applied to the roof, and the positive and negative loads applied to the exterior
Figure 6-21 View of a steel joist after the metal decking blew away. The decking was attached with puddle welds. However, at most of the welds, there was only superficial bonding of the metal deck to the joist, as illustrated at this weld. Only a small portion of the
Figure 6-22 View of another weld near the weld shown in Figure 6-21. At this weld, the deck was well bonded to the joist. When the decking blew off due to failure of nearby weak welds, at this location the metal decking tore and a portion of it remained attached to th
Figure 6-23 Portions of this waffled precast concrete roof deck were blown off. Bolts had been installed to provide uplift resistance; however, anchor plates and nuts had not been installed. Without the anchor plates, the dead load of the deck was inadequate to resist
Figure 6-24 Several of the precast twin-Tee roof and wall panels collapsed. The connection between the roof and wall panels provided very little uplift load resistance. This roof panel lifted because of combined effects of wind uplift and pretension.
Figure 6-25 Door sill pan flashing with end dams, rear leg, and turned-down front leg
Figure 6-26 Drip at door head and drip with hook at head
Figure 6-27 Door shoe with drip and vinyl seal
Figure 6-28 Neoprene door bottom sweep
Figure 6-29 Automatic door bottom
Figure 6-30 Interlocking threshold with drain pan
Figure 6-31 Threshold with stop and seal
Figure 6-32 Adjustable jamb/head weatherstripping
Figure 6-33 This suspended metal soffit was not designed for upward-acting wind pressure. Depending upon wind direction, soffits can experience either positive or negative pressure. Besides the cost of repairing damaged soffits, wind-borne soffit debris can cause prop
Figure 6-34 The interior walls of this classroom wing were constructed of unreinforced CMU. To avoid occupant injury, it is recommended that masonry walls adjacent to student areas be designed to resist wind loads as discussed in Section 6.11.1.
Figure 6-35 Failure of brick veneer
Figure 6-36 EIFS blow-off near a wall corner. At one area, the metal fascia was also blown in.
Figure 6-37 The metal edge flashing on this modified bitumen membrane roof was installed underneath the membrane, rather than on top of it and then stripped in. In this location, the edge flashing is unable to clamp the membrane down. At one area, the membrane was not
Figure 6-38 This metal edge flashing had a continuous cleat, but the flashing disengaged from the cleat and the vertical flange lifted up. However, the horizontal flange of the flashing did not lift. When a vertical flange disengages and lifts up, the edge flashing an
Figure 6-39 This coping was attached with ¼-inch diameter stainless steel concrete spikes at 12 inches on center. Use of exposed fasteners to attach the vertical flanges of copings and edge flashings has been found to be a very effective and reliable method. When the
Figure 6-40 Continuous bar near the edge of edge flashing or coping. If the edge flashing or coping is blown off, the bar may prevent a catastrophic progressive failure.
Figure 6-41 On this school, the fastener rows of the mechanically attached single-ply membrane ran parallel to the top flange of the steel deck. Hence, essentially all of the row’s uplift load was transmitted to only two deck fasteners at each joist (as illustrated in
Figure 6-42 View of the underside of a steel deck. The mechanically attached single-ply membrane fastener rows ran parallel to the top flange of the steel deck. The flange with the membrane fasteners carries essentially all of the uplift load because of the deck’s ina
Figure 6-43 The parapet on this school was sheathed with metal wall panels. The panels were fastened at 2 feet on center along their bottom edge, which was inadequate to resist the wind load. For mechanically attached parapet coverings, it is imperative to calculate s
Figure 6-44 This air terminal (“lightning rod”) was dislodged and whipped around during a windstorm. The single-ply membrane was punctured by the sharp tip in several locations. During prolonged high winds, repeated slashing of the membrane by loose conductors (“cable
Figure 6-45 Two complete windows, including their frames, blew out. The frames were attached with an inadequate number of fasteners, which were somewhat corroded. It is important to specify an adequate load path and to check its continuity during submittal review.
Figure 6-46 View of a typical window sill pan flashing with end dams and rear legs. Windows that do not have nailing flanges should typically be installed over a pan flashing.
Figure 6-48 The rooftop mechanical equipment on this school was blown over. The displaced equipment can puncture the roof membrane and, as in this case, rain can enter the school through the large opening that is no longer protected by the equipment.
Figure 6-49 This HVAC equipment had two supplemental securement straps. Both straps are still on this unit, but some of the other units on the roof had broken straps. The supplemental attachment was marginal; the straps were too light and the fasteners used to secure
Figure 6-50 The communications mast on this school was pulled out of the deck, resulting in a progressive peeling failure of the fully adhered single-ply membrane. There are several exhaust fans in the background that were blown off their curbs, but were retained on t
Figure 6-51 To overcome blow-off of the fan cowling, which is a common problem, this cowling was attached to the curb with cables. The curb needs to be adequately attached to carry the wind load exerted on the fan.
Figure 6-52 These wire-tied tiles were installed over a concrete deck. They were attached with stainless steel clips at the perimeter rows and all of the tiles had tail hooks. Adhesive was also used between the tail and head of the tiles. Wind-borne debris from heavy
Figure 6-53 At this school, a missile struck the fully adhered low-sloped roof (see arrow) and slid into the steep-sloped reinforced mechanically attached single-ply membrane. A large area of the mechanically attached membrane was blown away due to progressive membran
Figure 6-54 This fully adhered single-ply membrane was struck by a large number of missiles during a hurricane. Although a fully adhered system is not as vulnerable to progressive failure after debris impact as are mechanically attached and air-pressure equalized syst
Figure 6-55 View of a metal shutter designed to provide missile protection for windows. A metal track was permanently mounted to the wall above and below the window frame. Upon notification of an approaching hurricane, the metal shutter panels were inserted into the f
Figure 6-56 A violent tornado passed by this high school and showered the roof with missiles. The missile sticking out of the roof in the foreground is a double 2-inch by 6-inch. The portion sticking out of the roof is 13 feet long. It penetrated a ballasted EPDM memb
Figure 6-57 View of an elementary school corridor after passage of a violent tornado. Although corridors sometimes offer protection, they can be death traps as illustrated in this figure (fortunately the school was not occupied when it was struck). Schools in tornado-
Figure 6-58 This school had a cementitious wood-fiber deck (commonly referred to by the proprietary name “Tectum”). These two deck panels blew away because their attachment to the roof structure was inadequate. An SPF roof covering was over the panels; because of the [Go to Page]