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.

Research Interests

• 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

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.

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.

Education

• University of Wisconsin-Madison, Ph.D. Physical Chemistry 2005
• Calvin College, Grand Rapids, MI, B.A. Chemistry/Classical Civilization/Archaeology 1998

Professional Experience

Professional Organizations

• Society of Wood Science and Technology (SWST), Member (2008 - Current)
• American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), Member (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 & Products

• Glass, Samuel V; Boardman, Charles R.; Thybring, Emil Engelund; Zelinka, Samuel L. 2018. Quantifying and reducing errors in equilibrium moisture content measurements with dynamic vapor sorption (DVS) experiments.
• Thybring, Emil Engelund; Glass, Samuel V; Zelinka, Samuel L. 2019. Kinetics of water vapor sorption in wood cell walls: state of the art and research needs.
• Thybring, Emil E.; Boardman, Charles R.; Glass, Samuel V; Zelinka, Samuel L. 2019. The parallel exponential kinetics model is unfit to characterize moisture sorption kinetics in cellulosic materials.
• Zelinka, Samuel L.; Glass, Samuel V; Thybring, Emil Engelund. 2020. Evaluation of previous measurements of water vapor sorption in wood at multiple temperatures.
• Kordziel, Steven ; Glass, Samuel V; Boardman, Charles R.; Munson, Robert A.; Zelinka, Samuel L.; Pei, Shiling ; Tabares-Velasco, Paulo Cesar. 2020. Hygrothermal characterization and modeling of cross-laminated timber in the building envelope.
• Kordziel, Steven ; Pei, Shiling ; Glass, Samuel V; Zelinka, Samuel ; Tabares-Velasco, Paulo Cesar. 2019. Structure moisture monitoring of an 8-story mass timber building in the Pacific Northwest.
• Glass, Samuel V.; Wang, Jieying; Easley, Steve; Finch, Graham. 2013. Chapter 10: Enclosure--Building enclosure design for cross-laminated timber construction.
• Glass, Samuel V.; Gatland II, Stanley D.; Ueno, Kohta; Schumacher, Christopher J. 2017. Analysis of improved criteria for mold growth in ASHRAE standard 160 by comparison with field observations.
• Glass, Samuel V.; Zelinka, Samuel L. 2010. Moisture relations and physical properties of wood.

Publications

• Thybring, Emil E.; Boardman, Charles R.; Zelinka, Samuel L.; Glass, Samuel V. 2021. Common sorption isotherm models are not physically valid for water in wood.
• Glass, Samuel; Zelinka, Samuel; Thybring, Emil Engelund. 2021. Exponential decay analysis: a flexible, robust, data-driven methodology for analyzing sorption kinetic data.
• Zelinka, Samuel; Thybring, Emil E.; Glass, Samuel. 2021. Interpreting Dynamic Vapor Sorption (DVS) Measurements: Why Wood Science Needs to Hit the Reset Button.
• Pei, Shiling ; Stogdill, Jake ; Glass, Samuel V; Zelinka, Samuel ; Kordziel, Steven ; Tabares-Velasco, Paulo Cesar. 2021. Long-Term Moisture Monitoring Results of an Eight-Story Mass Timber Building in the Pacific Northwest.
• Glass, Samuel; Zelinka, Samuel. 2021. Moisture relations and physical properties of wood.
• Zelinka, Samuel L.; Kirker, Grant T.; Bishell, Amy B.; Glass, Samuel V. 2020. Effects of wood moisture content and the level of acetylation on brown rot decay.
• Kirker, Grant T.; Bishell, Amy; Glass, Samuel; Bechle, Nathan; Cappellazzi, Jed; Palmer, Jonathon; Hickey, William. 2020. Fungal Diversity Associated with Zones of the AWPA Fungal Decay Hazard Map.
• Boardman, Charles R.; Glass, Samuel V. 2020. Improving the Accuracy of a Hygrothermal Model for Wood-Frame Walls: A Cold-Climate Study.
• Boardman, Charles R.; Glass, Samuel V; Zelinka, Samuel L. 2020. Moisture redistribution in full-scale wood-frame wall assemblies: measurements and engineering approximation.
• Lepage, Robert ; Glass, Samuel V; Knowles, Warren ; Mukhopadhyaya, Phalguni . 2019. Biodeterioration models for building materials: critical review.
• Boardman, C.R. ; Glass, Samuel V; Munson, Robert ; Yeh, Borjen ; Chow, Kingston . 2019. Field moisture performance of wood-framed walls with exterior insulation in a cold climate.
• Boardman, Charles R.; Chow, Kingston ; Glass, Samuel V; Yeh, Borjen . 2019. Hygrothermal modeling of wall drying after water injection.
• Zelinka, Samuel L.; Bourne, Keith J.; Glass, Samuel V; Boardman, Charles R.; Lorenz, Linda ; Thybring, Emil Engelund. 2018. Apparatus for gravimetric measurement of moisture sorption isotherms for 1-100 g samples in parallel.
• Pásztory, Zoltán ; Horváth, Tibor ; Glass, Samuel V; Zelinka, Samuel . 2018. Experimental investigation of the influence of temperature on thermal conductivity of multilayer reflective thermal insulation.
• Kordziel, Steven ; Glass, Samuel V; Pei, Shiling ; Zelinka, Samuel L.; Tabares-Velasco, Paulo Cesar. 2018. Moisture monitoring and modeling of mass-timber building systems.
• Glass, Samuel V; Boardman, C.R. ; Yeh, Borjen ; Chow, Kingston . 2018. Moisture monitoring of wood-frame walls with and without exterior insulation in the Midwestern U.S.
• Zelinka, S.L. ; Kordziel, S. ; Pei, S. ; Glass, S.V. ; Tabares-Velasco, P.C. . 2018. Moisture monitoring throughout the construction and occupancy of mass timber builidings.
• Zelinka, Samuel L.; Glass, Samuel V; Thybring, Emil Engelund. 2018. Myth versus reality: do parabolic sorption isotherm models reflect actual wood water thermodynamics.
• Passarini, Leandro ; Zelinka, Samuel L.; Glass, Samuel V; Hunt, Christopher G. 2017. Effect of weight percent gain and experimental method on fiber saturation point of acetylated wood determined by differential scanning calorimetry.
• Glass, Samuel V.; Boardman, Charles R.; Zelinka, Samuel L. 2017. Short hold times in dynamic vapor sorption measurements mischaracterize the equilibrium moisture content of wood.
• Boardman, Charles; Glass, Samuel V.; Lebow, Patricia K. 2017. Simple and accurate temperature correction for moisture pin calibrations in oriented strand board.
• Zelinka, Samuel L.; Glass, Samuel V.; Jakes, Joseph E.; Stone, Donald S. 2016. A solution thermodynamics definition of the fiber saturation point and the derivation of a wood-water phase (state) diagram.
• Zelinka, Samuel L.; Passarini, Leandro; Colon Quintana, José L.; Glass, Samuel V.; Jakes, Joseph E.; Wiedenhoeft, Alex C. 2016. Cell wall domain and moisture content influence southern pine electrical conductivity.
• Zelinka, Samuel L.; Glass, Samuel V.; Boardman, Charles R.; Derome, Dominique. 2016. Comparison of the corrosion of fasteners embedded in wood measured in outdoor exposure with the predictions from a combined hygrothermal-corrosion model.
• Glass, Samuel V.; Yeh, Borjen; Herzog, Benjamin J. 2016. Effects of Exterior Insulation on Moisture Performance of Wood-Frame Walls in the Pacific Northwest: Measurements and Hygrothermal Modeling.
• Zelinka, Samuel L.; Glass, Samuel V.; Boardman, Charles R. 2016. Improvements to water vapor transmission and capillary absorption measurements in porous materials.
• Zelinka, Samuel L.; Glass, Samuel V.; Boardman, Charles R.; Derome, Dominique. 2016. Moisture storage and transport properties of preservative treated and untreated southern pine wood.
• Zelinka, Samuel L.; Wiedenhoeft, Alex C.; Glass, Samuel V.; Ruffinatto, Flavio. 2015. Anatomically informed mesoscale electrical impedance spectroscopy in southern pine and the electric field distribution for pin-type electric moisture metres.
• Boardman, C.R.; Glass, Samuel V. 2015. Basement radon entry and stack driven moisture infiltration reduced by active soil depressurization.
• Zelinka, Samuel L.; Bourne, Keith J.; Hermanson, John C.; Glass, Samuel V.; Costa, Adriana; Wiedenhoeft, Alex C. 2015. Force-displacement measurements of earlywood bordered pits using a mesomechanical tester.
• Glass, Samuel; Kochkin, Vladimir; Drumheller, S.; Barta, Lance. 2015. Moisture Performance of Energy-Efficient and Conventional Wood-Frame Wall Assemblies in a Mixed-Humid Climate.
• Boardman, CR; Glass, Samuel V. 2015. Moisture transfer through the membrane of a cross-flow energy recovery ventilator: Measurement and simple data-driven modeling.
• Zelinka, Samuel L.; Quintana, José L. Colon; Glass, Samuel V.; Jakes, Joseph E.; Wiedenhoeft, Alex C. 2015. Subcellular Electrical Measurements as a Function of Wood Moisture Content.
• Pásztory, Zoltán; Horváth, Tibor; Glass, Samuel V.; Zelinka, Samuel L. 2015. Thermal Insulation System Made of Wood and Paper for Use in Residential Construction.
• Glass, Samuel V.; Zelinka, Samuel L.; Johnson, Jay A. 2014. Investigation of Historic Equilibrium Moisture Content Data from the Forest Products Laboratory.
• Zelinka, Samuel L.; Glass, Samuel V.; Derome, Dominique. 2014. The effect of moisture content on the corrosion of fasteners embedded in wood subjected to alkaline copper quaternary treatment.
• Glass, Samuel V. 2013. Hygrothermal Anaylsis of Wood-Frame Wall Assemblies in a Mixed-Humid Climate.
• Glass, Samuel V.; TenWolde, Anton; Zelinka, Samuel L. 2013. Hygrothermal Simulation: A Tool for Building Envelope Design Analysis.
• Boardman, C.R.; Glass, Samuel V. 2013. Investigating Wind-Driven Rain Intrusion in Walls with the CARWASh.
• Jakes, Joseph E.; Plaza, Nayomi; Stone, Donald S.; Hunt, Christopher G.; Glass, Samuel V.; Zelinka, Samuel L. 2013. Mechanism of Transport Through Wood Cell Wall Polymers.
• TenWolde, Anton; Glass, Samuel V. 2013. Moisture in Crawl Spaces.
• Clausen, Carol A.; Glass, Samuel V. 2012. Build Green: Wood Can Last for Centuries.
• Zelinka, Samuel L.; Lambrecht, Michael J.; Glass, Samuel V.; Wiedenhoeft, Alex C.; Yelle, Daniel J. 2012. Examination of water phase transitions in Loblolly pine and cell wall components by differential scanning calorimetry.
• Zelinka, Samuel L.; Derome, Dominique; Glass, Samuel V. 2011. Combining hygrothermal and corrosion models to predict corrosion of metal fasteners embedded in wood.
• Boardman, C.R.; Glass, Samuel V.; Carll, Charles G. 2011. Moisture meter calibrations for untreated and ACQ-treated southern yellow pine lumber and plywood.
• Glass, Samuel V. 2010. A laboratory facility for research on wind-driven rain intrusion in building envelope assemblies.
• Boardman, C. R.; Glass, Samuel V.; Carll, Charles G. 2010. Estimating foundation water vapor release using a simple moisture balance and AIM-2 : case study of a contemporary wood-frame house.
• Zelinka, Samuel L.; Derome, Dominique; Glass, Samuel V. 2010. From laboratory corrosion tests to a corrosion lifetime for wood fasteners : progress and challenges.
• Glass, Samuel V.; Carll, Charles G.; Curole, Jay P.; Voitier, Matthew D. 2010. Moisture performance of insulated, raised, wood-frame floors : a study of twelve houses in southern Louisiana.
• Zelinka, Samuel L; Glass, Samuel V. 2010. Water vapor sorption isotherms for southern pine treated with several waterborne preservatives.
• Glass, Samuel V.; TenWolde, Antoni. 2009. Review of moisture balance models for residential indoor humidity.
• Glass, Samuel V.; Carll, Charles G. 2009. Moisture meter calibration for untreated and ACQ-treated southern yellow pine plywood.
• Clausen, Carol A.; Glaeser, Jessie A.; Glass, Samuel V.; Carll, Charles. 2009. Occurrence of mold in a two-story wood-frame house operated at design indoor humidity levels.
• Zelinka, Samuel L.; Glass, Samuel V.; Stone, Donald S. 2008. A percolation model for electrical conduction in wood with implications for wood-water relations.
• Glass, Samuel V. 2007. Measurements of moisture transport in wood-based materials under isothermal and nonisothermal conditions.
• Glass, Samuel V.; TenWolde, Anton. 2007. Review of in-service moisture and temperature conditions in wood-frame buildings.

Research Highlights

Highlight	Title	Year
FPL-2010-005	A percolation model for water and electrical conduction in wood with implications for durability Recently, researchers at the Forest Products Laboratory and University of Wisconsin have developed a new model of electrical conduction in wood ...	2010
FPL-2010-001	Centennial Edition, Wood Handbook—Wood as an Engineering Material The Wood Handbook—Wood as an Engineering Material serves as a primary reference document for a wide variety of users-from the general publ ...	2010
FPL-2019-71	Development of New Kinetics Models for Water Vapor Sorption in Wood Wood is constantly exchanging water with its environment and these exchanges control nearly all of wood's amazing properties. USDA Forest Servic ...	2019
FPL-2017-120	Improving experimental techniques that probe wood-moisture interactions Prior methods using dynamic vapor sorption instruments mischaracterized the equilibrium moisture content of wood. Equilibrium is reached after m ...	2017
FPL-2018-23	Improving the Accuracy of Automated Instruments for Moisture in Wood Automated instruments are increasingly used for measuring the equilibrium moisture content of wood. Research finds that common methods have much ...	2018
FPL-2020-108	Improving the Tools and Practice for Designing Moisture-Safe Wood Buildings FPL researchers predict the future! Will this new wood structure be safe and durable in the climate for which it is designed?	2020
FPL-2020-106	Investigating the Role of Moisture in Durability of Acetylated Wood FPL researchers join international effort to investigate fungal decay resistance of acetylated wood.	2020
FPL-2019-76	Keeping Wood-Frame Housing Safe and Warm Is it okay to add exterior insulation and cover the wood sheathing to make your home even more energy-efficient? USDA Forest Service researchers ...	2019
FPL-2015-199	Managing Moisture in Energy-efficient Wall Systems Moisture durability is critical for design and construction of energy-efficient buildings. Field measurements of moisture characteristics for hi ...	2015
FPL-2010-004	Modeling indoor humidity in homes Indoor humidity levels in a home influence not only occupant comfort and indoor air quality but also the durability of the building, especially ...	2010
FPL-2011-11	Moisture Control in Crawl Spaces in Louisiana Builders and homeowners in the Gulf Region often ask how to insulate a crawl space to avoid moisture problems. The Forest Products Laboratory (F ...	2011
FPL-2019-80	Monitoring Moisture Levels in Mass Timber Buildings Detailed measurements on moisture levels in mass timber buildings in the United States are scarce. USDA Forest Service researchers are working w ...	2019
FPL-2014-175	Possibilities and Pitfalls of Computer Simulation for Building Moisture Analysis Moisture problems are much less expensive to correct in the building design phase than after the building is constructed. Computer-based simulat ...	2014
FPL-2017-114	Scientists study how water changes wood Water causes a host of wood damage mechanisms such as mold, decay, fastener corrosion, and splitting. This research elucidates how water chan ...	2017
FPL-2018-22	Updating a Building Design Standard with Improved Criteria for Preventing Mold Growth A consensus standard for building design that addresses moisture control analysis was recently revised to improve the criteria for preventing mo ...	2018
FPL-2013-143	Wood Construction Goes Beyond Its Traditional Roots As interest in sustainable building options continues to grow. Wood construction is going beyond its traditional roots in housing and expanding ...	2013