Technical Best Practices

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.

Checklists for Mitigating and Remediating Mold on Wood Structural Building Components

The following checklists are to be used as a practical guide in conjunction with the information on mold provided in SBCA Research Report 1807-01: “Mold on Structural Building Components.”

Deck Ledger Attachment to Residential Wood Truss Floor Systems

This Research Report provides construction details for residential deck ledger attachment to metal plate connected wood truss floor systems. Proper attachment of the deck ledger to the house is critical for ensuring that an “attached” deck is safely and securely supported at this location. 

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.

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-Retardant Treated Lumber Use: Ceiling Assemblies in Type III Buildings

This report focuses on building code requirements for using fire retardant treated wood (FRTW) in floor/ceiling and roof/ceiling assemblies in Type III building construction. 

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.

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.

Impact of C&C 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. 

Insulating Concrete Form Sill Plate Requirements

This Research Report will look specifically at the sill plate requirements according to the 2009, 2012, and 2015 International Residential Code (IRC) and International Building Code (IBC) and clarify if a sill plate is required in the following conditions:

• Flat truss bottom chord bearing on ICF wall.
• Flat truss top chord bearing on ICF wall.
• Roof truss bearing on ICF wall.

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.

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.

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. 

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.