SBCA Scientific Research Reports
SBCA Research Reports
Gypsum Joint Ridging and Cracking
Drywall cracking and ridging are typical problems seen in ceilings and walls of homes. Sometimes, both of these issues appear at the same location, with cracking appearing in wetter months and ridging in drier months. This problem has become more widespread as homeowners insist on larger rooms and open floor plans that have large clear span areas. This Research Report evaluates local environment changes that play a significant role in every gypsum ridging and cracking case.
|Moisture Control, Installation, Construction, Performance|
Bottom Chord Live Load Concurrency and Truss Design
The truss industry is currently employing ASCE as its source for the loading of live loads to the bottom chord of trusses for uninhabitable attics, in accordance with the International Residential Code and the International Building Code. However, there currently is a discrepancy between ASCE 7, the IBC and the IRC. This report examines the discrepancy and the correct loading for proper truss design.
Truss Heel Heights and the Energy Requirements
This report discusses ways of increasing the energy efficiency requirements of the building envelope within the context of the requirements of the 2009, 2012 and 2015 International Residential Code (IRC) and IECC for ceiling insulation and truss heel heights.
|Energy Efficiency, Roof Trusses, Energy Codes, Residential Codes (IRC)|
Exterior Brick Masonry Veneer supported by Wood Trusses
Code compliant use of Metal Plate Connected Wood Trusses (MPCWT) to support brick veneer can be accomplished by both individual designs and by adhering to the recommendations that follow within this report. This discussion focuses on a common use of MPCWT’s; the gable end at the transition from a wider section of a building to a narrower section.
|Cladding Attachments, Connections, Construction|
Deflection Limits for Floor Trusses
There are circumstances when the deflection requirements for a specific structure that utilizes floor trusses as structural members are questioned. The current residential and commercial building codes provide minimum design requirements for loads and for deflection of structural floor members, which also apply to floor trusses. The building designer may specify more stringent requirements. This research report will focus on manufacturer or trade association deflection requirements for a number of floor topping/covering related products
|Floor Trusses, Non-Residential Codes (IBC), Residential Codes (IRC)|
Floor Vibrations Causes and Control Methods
While the perception of floor vibrations is subjective from one person to the next, overall floor systems which exhibit lower deflections and less acceleration from vibration sources tend to be perceived better than other designs. To accomplish this, the designer may elect to do one or a combination of things, covered in this report.
|Floor Trusses, Product Performance, Performance, Products|
Type III-A Buildings: Lumber Use
Many factors go into classifying buildings. Each type will have different allowable height, allowable number of stories and allowable area limitations based on the classification. This report will focus on Type III-A building construction using fire retardant treated wood (FRTW).
|Fire Resistance, Lumber, Lumber Treatments|
Impact of CC loads due to ASCE/SEI 7-16
ASCE/SEI 7-16 Minimum Design Loads for Buildings and Other Structures has revised Chapter 30 regarding Components & Cladding (C&C) wind loads on roofs. This report clarifies the type and scope of changes being made that will also change in the 2018 edition of the model building codes.
|Loads, Non-Residential Codes (IBC), Residential Codes (IRC), Design|
Sealed Truss Placement Diagrams - Texas
It can be often misunderstood whether a Truss Design Engineer has the responsibility to seal a Truss Placement Diagram (TPD). The purpose of this Research Report is to provide the relevant code sections from the latest editions of the International Building Code (IBC) for thorough analysis and interpretation, as they relate to the state of Texas.
|Design Documents, Engineering, Scope of Work|
Special Floor Loading Considerations in Typical Residential Construction
This report will explore some special floor loading issues that are not specifically mentioned in the building codes and require special attention to ensure that the floor system is properly designed with no serviceability issues. The following are the major issues that will be discussed: stone/ceramic tiles, large concentrated loads and floor vibrations.
|Bracing & Restraint, Loads|
Sound Transmission in Wood Floor and Roof Trusses
Controlling sound transmission in buildings through wall, floor and ceiling assemblies is important for the comfort level and enjoyment of building occupants as they live, work and play in these buildings. This report aims to explore the methods one can use to reduce sound transmission in assemblies constructed with wood trusses.
|Floor Trusses, Roof Trusses, Products|
Sealed Truss Placement Diagrams - IRC
It can be often misunderstood whether a Truss Design Engineer has the responsibility to seal a Truss Placement Diagram (TPD). The purpose of this Research Report is to provide the relevant code sections from the latest editions of the International Residential Code (IRC) for thorough analysis and interpretation.
|Engineering, Loads, Scope of Work|
Submittal Packages and Jobsite Packages: What Should Be Included?
In order to promote the safe installation of building components including trusses, manufacturers send out a Jobsite Package to the construction site with the truss delivery. These Jobsite Packages include the Truss Submittal Package. The Truss Submittal Package includes the information that if required will be submitted to the Contractor/Building Designer, who if required will submit it to the local building official.
|Building Component Safety Information (BCSI), Jobsite Documents, Jobsite Packages, Jobsite Safety|
Single Membrane Floor Protection Requirements of 2012 IRC Section R501.3 & 2015 IRC Section R302.13
This Research Report aims to enhance fire performance and fire safety characteristics through the application of a gypsum wallboard membrane.
|Fire Testing, Floor Trusses, Fire Codes|
Sprinkler Systems and Wood Trusses
The goal of this Research Report is to assist in designing safe buildings economically, especially when sprinkler systems are required or desired in the design.
|Fire Resistance, Fire Codes, Loads|
Fire Endurance Calculation for Wood Truss Structural Framing Systems: 2-Hour Assembly
Fire endurance ratings may be mandated by code for many assemblies in both floor and roof framing systems. This Research Report discusses methodologies to calculate 2-hour fire endurances of a given assembly.
|Fire Resistance, Fire Codes|
Fire Resistance Rated Truss Assemblies
A fire endurance rating may be mandated by code for many of the applications where trusses could be used in floor/ceiling, roof/ceiling or in attic separation applications. This Research Report discusses 5 different methods for determining fire resistance.
|Fire Resistance, Fire Codes, Design, Performance|
Fire Retardants and Truss Design
Depending on the type of fire-retardant treatment (FRT) used, materials may require a change in design values and reduction in connector capacity. This report intends on providing a clear perspective of interiror FRT wood used in Truss designs.
|Fire Resistance, Lumber Treatments, Engineering|
Truss Uplift Design
ASCE/SEI 7-10, Minimum Design Loads of Buildings and Other Structures, lists two methods for calculating wind pressures: Main Wind Force Resisting System (MWFRS) and Components & Cladding (C&C). This report will provide information to assist the building designer in deciding upon the appropriate analysis method for uplift due to wind loading.
|Roof Trusses, Engineering, Loads|
Sealed Truss Placement Diagrams - IBC
It can be often misunderstood whether a Truss Design Engineer has the responsibility to seal a Truss Placement Diagram (TPD). The purpose of this Research Report is to provide the relevant code sections from the latest editions of the International Building Code (IBC) for thorough analysis and interpretation.
|Engineering, Loads, Scope of Work|
Floor Truss Ribbon Board Load Path
The capacity of a ribbon board and its system through the composite of the ribbon board, floor sheathing and bottom plate of the wall has not been ascertained. In order to provide better guidance, a series of tests were conducted in order to determine the capacity of the ribbon board system.
|Floor Trusses, Loads|
Overdriven Nails in Structural Sheathings
All building codes provide provisions for the attachment of structural sheathing to wall and roof framing members. In almost every case, the published capacity of the sheathing and fasteners assume the head of the fastener is flush with the surface of the sheathing. This Research Report discusses guidance when fasteners are overdriven.
|Connectors & Fasteners, Sheathing, Installation|
Long Span Truss Installation
Long span trusses can pose significant risk to installers. The dimensions and weight of a long span truss can create instability, buckling and collapse of one or many trusses, if not handled, installed, restrained and braced properly. As such, they require more detailed safety and handling measures than shorter span trusses. This research report provides guidelines for proper handling and installation of long span trusses for both wood and cold-formed steel.
|Bracing & Restraint, Roof Trusses, Installation, Non-Residential Codes (IBC), Construction, Residential Codes (IRC), Design, Products|
Heel Blocking Requirements and Capacity Analysis
Both the International Residential Code (IRC) and the International Building Code (IBC) require that the top plates of exterior braced wall panels be attached to the rafters or roof trusses above. This report will discuss the code requirements and provide alternate engineered designs and capacities, including heel/bird blocking, partial height blocking and blocking panels.
|Connections, Engineering, Loads|
The repair and modification of metal plate connected wood trusses can be a very complicated subject, because each situation must be analyzed individually. This Research Report will give an overview of the fundamental principles behind truss repair that inform the truss designer’s approach in all truss scenarios.
|Design Documents, Engineering, Field Repairs & Alterations|
Sealed Truss Placement Diagrams - California
It can be often misunderstood whether Truss Designers have the responsibility to seal a Truss Placement Diagram (TPD). The purpose of this Research Report is to provide the relevant code sections from the International Building Code (IBC) and the California Building Code for a thorough analysis and interpretation.
|Design Documents, Engineering, Scope of Work|
Cantilevered Sill Plates: Use with Wood Trusses to Align with Varying Thicknesses of Exterior Sheathing
The prescriptive residential energy code requirements found in the 2009, 2012 and 2015 International Residential Code (IRC) include requirements for continuous insulation at foundations in several climate zones. This Research Report discusses the issue of cantilevered sill plates supporting metal plate connected wood trusses installed parallel and perpendicular to the foundation walls where there is a potential for discontinuous planes between the exterior wall above the sill plate and the foundation insulation planes.
|Floor Trusses, Loads|
Lay-On Gable Connection: An Analysis of a Toe Nail Connection Visible After Sheathing is Installed
A lay-on gable frame is typically connected from the top during truss placement, but after sheathing is installed, this connection is no longer visible for the building inspector to verify. This creates a need for an alternate connection that is visible from below. The goal of this Research Report is to analyze a simple, cost-effective, toe nail connection between the lay-on gable frames and supporting truss system that is visible after sheathing is installed.
|Roof Trusses, Connections, Loads|
Sprinkler Loads on Trusses
Building Designers need to account for the dead and live loads of fire sprinkler systems, in addition to the other load requirements imposed under the model building codes. Truss Designers are responsible for incorporating the additional load from the fire sprinkler systems into the truss design. The information in this Research Report is applicable to both floor and roof systems. Only vertical loads from fire sprinkler systems are discussed; lateral loads, where required, should be evaluated separately by a Registered Design Professional.
|Fire Codes, Loads|
Resilient Channel or Hat Channel: Use to Meet the Lateral Restraint/Bracing Requirements of the Bottom Chords of Wood Truss Floor Systems
Minimum top and bottom chord permanent lateral restraint/bracing of structural roof or floor trusses is assumed to be adequate when using code-compliant roof and/or ceiling diaphragms. This lateral restraint/bracing is typically accomplished with code-compliant roof /floor sheathing and fastener spacing and/or code-compliant gypsum ceiling material and fastener spacing or purlins at a given on-center spacing.
|Bracing & Restraint|