Who Should Attend

The audience for this course is engineers involved in the design of wood construction projects, residential designers, metal-plate-connected (MPC) wood truss designers, engineered wood product (EWP) designers, general contractors, and building code officials, plan reviewers and inspectors.

Overview of Course Content

The selection of the twelve topics was guided by good practice design including consideration for how structural design and applicable codes, material properties, and well-defined professional specifications can impact in-service outcomes. Participants will earn 15-hours of continuing education credit (1.5 CEUs) and a certificate at the completion of the course. The topics and instructor follow.

Impact of Wood Quality on Physical and Design Properties of Lumber
The anatomy, cellular structure, and chemical composition of wood will be reviewed. Growth characteristics of a tree, such as wood density, density variation, juvenile wood/mature wood distribution, proportion of heartwood/sapwood, fiber length, fibril angle, compression wood, knots, and grain angel will be discussed and related to the anisotropic design properties of structural lumber, lumber grades, and performance in-service.
Joseph Loferski, Professor, Virginia Tech

Design Values for “Multi-Species and Country Grademarked” Lumber
Lumber mills sometimes process logs from different regions and countries, and this has given rise to a different type of grade stamp for dimension lumber referred to in a new NDS Supplement Table 4G as “Multi-Species and Country Grademarked Visually Graded Dimension Lumber.” Participants will learn how to interpret the grade stamps, the basis of the published design values, methods to calculate fastener and connector values, and ways to specify design values for wood trusses, wall framing, shear walls and other applications.
Frank Woeste, Professor Emeritus, Virginia Tech

Design of Loadbearing Tall Wood Studs for Wind and Gravity Loads
Proper design of wood structures to resist high wind loads requires the correct use of wind load provisions and member design properties. A thorough understanding of the interaction between wind loads and material properties is important in the design process. Adjustments from reference wind conditions to extreme-value peak gusts require designers to make similar adjustments to design properties to ensure equivalent and economic designs. Wind load provisions have been developed for the design of major structural elements using Main Wind-Force Resisting System (MWFRS) loads and secondary cladding elements using Component & Cladding (C&C) loads. Elements and subassemblies which receive loads both directly and as part of the main wind force resisting system, such as wall studs, must be checked independently for MWFRS loads and C&C loads. A loadbearing stud wall design example based on the allowable stress design methods outlined in AWC's 2018 National Design Specification® (NDS®) for Wood Construction and 2018 Wood Frame Construction Manual along with ASCE 7-16 Minimum Design Loads and Associated Criteria for Buildings and Other Structures will demonstrate standard design checks for limit states of strength and deflection.
John “Buddy” Showalter, P.E., Senior Engineer, International Code Council

Mitigating Wood-Framed Egress Stair Stringer Failures
Shortcomings of wood frame egress stair construction and insufficient stringer design capacity can be traced to three sources; the absence of code prescriptive guidelines for stair stringers, the rarity of building design professionals to understand, analyze, and specify project specific stair stringers, and stringer support/connection details. This unit reviews available wood-framed stair stringer prescriptive information to form a rational approach of egress stringer design and evaluation for use in high live load applications.
Scott Coffman, Construction Science & Engineering, Westminster, SC

Permanent Truss Bracing: Engineered and Prescriptive Design
Permanent truss bracing design or specification and installation remains a challenge in-practice. This presentation will include two design methods for the design professional to consider, either an “engineered” permanent bracing design or permanent bracing design accomplished by specifying a “prescriptive” method (2020 BCSI) with supplemental bracing instructions for the contractor as applicable.
Frank Woeste, Professor Emeritus, Virginia Tech

Errors in Substituting Dead Load for Live Load in Wood Design
While it is common for designers to assume localized and elevated dead loads are offset by the code minimum live-load, the assumption is not consistent with building code, and it does not take into account in-service performance impacted by differential deflection, long term creep, and the load duration factor. Common floor loading scenarios are analyzed, and recommended practices presented to facilitate the design and installation of products to perform as intended.
Scott Coffman, Construction Science & Engineering, Westminster, SC

Specifying Roof and Floor Trusses per ANSI/TPI 1-2014
ANSI/TPI 1—2014 National Design Standard for Metal-plate-connected Wood Truss Construction, Chapter 2, Section 2.3.2.4 defines the specific construction details and truss design variables needed by the components designer and truss engineer to design and manufacture the truss elements of the building. In addition, it states that this information shall be included in the Construction Documents and provided by the Building Designer, typically a registered engineer or architect for IBC type construction. ANSI/TPI 1-2014, Section 2.3.2.4, will be reviewed in the context of why the information is required, to what extent it is commonly and sufficiently provided, and how Building Designers can improve their specifications when applicable.
Chawn Duty, P.E., UFP Site Built

Floor Vibration Research Summary & Design Options to Minimize Annoying Vibration Complaints
Full-scale laboratory floors using solid-sawn, I-joists, and floor trusses were tested under static and dynamic loads at Virginia Tech over several years under the direction of Dr. Dan Dolan. The laboratory testing data that included occupied residential floor tests will be summarized. A calculation method for predicting the likelihood of annoying floor vibration complaints in-service was developed and will be demonstrated by examples. In addition, practical steps to improve floor joist, I-joist, or wood truss floor vibration performance by design methods and floor construction will be presented.
Frank Woeste, Professor Emeritus, Virginia Tech

Tall Mass Timber and the Building Code
The 2021 International Building Code (IBC) allows for the construction of tall mass timber buildings with larger heights and areas than previously permitted in Types III, IV, and V construction. Mass timber includes any product currently permitted for use in Type IV (heavy timber) construction such as cross-laminated timber (CLT), structural composite lumber (SCL), glued laminated timber (glulam), mechanically laminated decking (aka nail-laminated timber, NLT), and large section sawn timbers. Research and development conducted in support of new tall mass timber construction types IV-A, IV-B, and IV-C in the 2021 IBC will be presented.
John “Buddy” Showalter, P.E., Senior Engineer, International Code Council

Fire-Resistance Design of Mass Timber Members and Connections
The 2021 International Building Code (IBC) contains new requirements for minimum fire-resistance ratings for mass timber elements used in new construction Types IV-A, IV-B, and IV-C, whether exposed wood (where permitted) or protected with noncombustible materials. Noncombustible protection for mass timber in Types IV-A and IV-B construction serves to provide a portion of the fire resistance of individual elements. A designer can calculate the fire-resistance rating of a protected wood element by adding the fire-resistance rating of the unprotected heavy timber member to protection provided by a noncombustible material applied to exposed wood. The 2021 IBC also requires the connections of mass timber structural members to be protected with materials that have the required fire-resistance rating. New code provisions provide two options for demonstrating compliance with this requirement for connections in Types IV-A, IV-B, and IV-C construction: a testing option and a calculation option. A calculation method will be presented.
John “Buddy” Showalter, P.E., Senior Engineer, International Code Council

Balcony and Deck Design Update per the 2018 IBC/IRC
Cantilevered balconies have limited structural redundancy, and as such, require special attention by design professionals and other parties involved in the construction process. In addition to reviewing the 2018 IBC balcony provisions that were motivated by the 2015 Berkeley balcony collapse, “good practice” design measures for redundant protection of the wood-framing in-service will be presented. New provisions for deck joist-to-ledger or -beam connections and corrosion protection of deck fasteners and connectors exposed to salt water or located within 300 feet of a saltwater shoreline will be reviewed.
Frank Woeste, Professor Emeritus, Virginia Tech

Durability Issues—Decay, Insects and Design/Detailing for Durability
An unstated assumption made by structural designers is that the wood products involved will be protected from decay and insect damage in-service. This presentation addresses the types of organisms and insects that can cause structural deterioration and ways to select materials and detail buildings to mitigate the risks.
Joseph Loferski, Professor, Virginia Tech