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Samuel V. Glass

Samuel V. Glass
Research Physical Scientist
Building and Fire Sciences
One Gifford Pinchot Drive
Madison, WI 53726-2398
United States
Current Research

Wood structures can endure for centuries if they remain sufficiently dry. As the construction industry evolves, research is needed to protect wood buildings from the potential effects of moisture. Proper design, operation, and maintenance of wood buildings are critical to prevent moisture-induced damage, such as mold growth, wood decay, and corrosion of metal fasteners.

Dr. Glass conducts research within the Building and Fire Sciences Research Work Unit at the Forest Products Laboratory. His research focuses on the building envelope, the collective elements that separate the interior and exterior environments, including the foundation, exterior walls, and roof. Dr. Glass investigates the relationships between moisture, energy efficiency, and durability in residential and non-residential wood buildings. Primary research objectives include

  • Advancing the fundamental understanding of wood–moisture interactions;
  • Quantifying moisture transfer in the building envelope;
  • Developing tools for predicting moisture-induced damage in buildings; and
  • Developing moisture control strategies for cross-laminated timber, a relatively new engineered wood product with vast potential for use in mid-rise and high-rise buildings.
Past Research

Dr. Glass conducted his doctoral research in the Department of Chemistry at the University of Wisconsin-Madison. He investigated how surfactant films at the gas-liquid interface control gas uptake and evaporation of water. These studies contributed to understanding chemical reactions that occur in sulfuric acid droplets in the upper troposphere and lower stratosphere, which affect ozone levels.

Research Interest
  • Wood−moisture interactions
  • Water vapor sorption in wood
  • Moisture-related properties of wood and wood products
  • Cross-laminated timber (CLT)
  • Moisture control in buildings
  • Heat, air, and moisture transfer in the building envelope
  • Interior and exterior moisture loads on the building envelope
  • Tools for predicting mold growth, wood decay, and corrosion of metal fasteners
  • Hygrothermal modeling
  • Instrumentation for monitoring moisture levels in building assemblies
Why This Research Is Important

Moisture control in wood buildings is important for human health, building sustainability, and conservation of the forest resource. Excessive moisture levels in buildings can lead to mold growth and respiratory health problems for occupants. Preventing moisture problems contributes to building sustainability by extending the service life. The sustainability and health of America's forests depend on sound conservation practices, including utilization. Efficient wood utilization reduces the risk and impacts of wildfire, provides incentives for private landowners to maintain forest land, and provides a critical source of jobs in rural America. Use of wood as a green building material is important for climate change mitigation because wood products store carbon for as long as the building exists. Wood products require less energy to process than other building materials such as steel or concrete, and use of wood produces less air pollution, solid wastes, and greenhouse gases. These benefits hinge on efficient and proper use of wood in construction.

  • University of Wisconsin-Madison, Ph.D., Physical Chemistry, 2005
  • Calvin College, Grand Rapids, MI, B.A., Chemistry/Classical Civilization/Archaeology, 1998
Professional Experience
  • Research Physical Scientist,  USDA Forest Products Laboratory,  2005 - Current
  • Research Assistant,  University of Wisconsin-Madison, Department of Chemistry,  2001 - 2005
  • Teaching Assistant,  University of Wisconsin-Madison, Department of Chemistry,  1999 - 2001
Professional Organizations
  • Member,  Society of Wood Science and Technology (SWST),  2008 - Current
  • Member,  American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE),  2005 - Current
    Standing Standard Project Committee 160, Criteria for Moisture-Control Design Analysis in Buildings; Technical Committee 1.12, Moisture Management in Buildings; Technical Committee 4.4, Building Materials and Building Envelope Performance
Featured Publications
Other Publications
Research Highlights

Improving experimental techniques that probe wood-moisture interactions

Year: 2017
Prior methods using dynamic vapor sorption instruments mischaracterized the equilibrium moisture content of wood. Equilibrium is reached after much longer times than previously claimed. This project provides a basis for methods that improve accuracy.

Improving the Accuracy of Automated Instruments for Moisture in Wood

Year: 2018
Automated instruments are increasingly used for measuring the equilibrium moisture content of wood. Research finds that common methods have much larger errors than claimed in the literature, so researchers developed a method to improve accuracy.

Updating a Building Design Standard with Improved Criteria for Preventing Mold Growth

Year: 2018
A consensus standard for building design that addresses moisture control analysis was recently revised to improve the criteria for preventing mold growth.

Modeling indoor humidity in homes

Year: 2010
Indoor humidity levels in a home influence not only occupant comfort and indoor air quality but also the durability of the building, especially in cold climates. Researchers at the Forest Products Laboratory undertook a critical assessment of the literature to determine the reliability of other para...

Development of New Kinetics Models for Water Vapor Sorption in Wood

Year: 2019
Wood is constantly exchanging water with its environment and these exchanges control nearly all of wood's amazing properties. USDA Forest Service research reveals that this process is still not understood and old models that were thought to explain these processes are not physically valid.

Keeping Wood-Frame Housing Safe and Warm

Year: 2019
Is it okay to add exterior insulation and cover the wood sheathing to make your home even more energy-efficient? USDA Forest Service researchers at the Forest Products Laboratory investigate under what conditions this practice is safe.

Monitoring Moisture Levels in Mass Timber Buildings

Year: 2019
Detailed measurements on moisture levels in mass timber buildings in the United States are scarce. USDA Forest Service researchers are working with Colorado School of Mines to monitor conditions in mass timber buildings in three different U.S. climates.

Improving the Tools and Practice for Designing Moisture-Safe Wood Buildings

Year: 2020
FPL researchers predict the future! Will this new wood structure be safe and durable in the climate for which it is designed?

Moisture Control in Crawl Spaces in Louisiana

Year: 2011
Builders and homeowners in the Gulf Region often ask how to insulate a crawl space to avoid moisture problems. The Forest Products Laboratory (FPL), in cooperation with Louisiana State University Agricultural Center, monitored conditions in a dozen homes in New Orleans and Baton Rouge to provide res...

Possibilities and Pitfalls of Computer Simulation for Building Moisture Analysis

Year: 2014
Moisture problems are much less expensive to correct in the building design phase than after the building is constructed. Computer-based simulation tools allow designers to gauge the risk of moisture problems. Although simulation can be useful as a design tool, designers must be aware of model limit...

Managing Moisture in Energy-efficient Wall Systems

Year: 2015
Moisture durability is critical for design and construction of energy-efficient buildings. Field measurements of moisture characteristics for highly insulated walls in mixed-humid climates are lacking. Researchers from the Forest Service’s Forest Products Laboratory in Madison, Wisc., and Home Innov...

Scientists study how water changes wood

Year: 2017
Water causes a host of wood damage mechanisms such as mold, decay, fastener corrosion, and splitting. This research elucidates how water changes wood and leads to these wood damage mechanisms.

A percolation model for water and electrical conduction in wood with implications for durability

Year: 2010
Recently, researchers at the Forest Products Laboratory and University of Wisconsin have developed a new model of electrical conduction in wood that provides a good fit to experimental data, offers insight into the mechanism of conduction, and integrates well with other experiments that probe the st...

Investigating the Role of Moisture in Durability of Acetylated Wood

Year: 2020
FPL researchers join international effort to investigate fungal decay resistance of acetylated wood.

Wood Construction Goes Beyond Its Traditional Roots

Year: 2013
As interest in sustainable building options continues to grow. Wood construction is going beyond its traditional roots in housing and expanding into mid-rise, high-rise, and non-residential applications. To support this trend, a new U.S. guide for the early adoption of cross-laminated timber, an inn...

Centennial Edition, Wood Handbook—Wood as an Engineering Material

Year: 2010
The Wood Handbook—Wood as an Engineering Material serves as a primary reference document for a wide variety of users-from the general public through architects and design engineers who use wood in highly engineered structures.