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6 records – page 1 of 1.

Control of Solar-Driven Moisture Diffusion in Cross-Laminated Timber Walls with Absorptive Claddings

https://research.thinkwood.com/en/permalink/catalogue717
Topic
Design and Systems
Moisture
Material
CLT (Cross-Laminated Timber)
Application
Walls
Author
Glass, Samuel
Organization
Forest Products Laboratory
Format
Report
Material
CLT (Cross-Laminated Timber)
Application
Walls
Topic
Design and Systems
Moisture
Keywords
Moisture Content
Absorptive Claddings
US
Climates
Research Status
In Progress
Summary
Prior research showed that inward moisture diffusion from absorptive claddings such as brick veneer, stucco, or manufactured stone veneer can be significant in wood-frame walls. The inward migration of moisture is greatest when the cladding is heated by the sun after being wetted by rain. The same phenomenon is likely to occur in CLT walls with these types of claddings (Fig. 1). General guidance on CLT building envelope design was published in chapter 10 of the U.S. CLT Handbook, which cautions that inward diffusion of moisture from absorptive claddings could lead to moisture accumulation in CLT based on initial computer modeling predictions. Experimental measurements are needed to provide a stronger basis for design of CLT exterior walls. The objectives of the project are to measure moisture conditions in CLT walls with absorptive claddings under exposure to simulated rain and sun and to identify design and construction practices that minimize the risk of moisture accumulation in different U.S. climates.
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Cross-Laminated Timber Roof Panels at the Promega Corporation Facility: Documenting Installation and Monitoring In-Service Moisture Conditions

https://research.thinkwood.com/en/permalink/catalogue801
Year of Publication
2013
Topic
Serviceability
Moisture
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Glass, Samuel
Romanin, Jennifer
Schumacher, Jim
Spickler, Kris
Organization
Forest Products Laboratory
Year of Publication
2013
Format
Report
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Serviceability
Moisture
Keywords
Moisture
Temperature
Installation Process
Sensors
Research Status
Complete
Summary
The USDA Forest Products Laboratory (FPL) has, for the past two years, been assisting in removing technical barriers to the use of CLT and trying to develop interest in the United States for its utilization. Coincidentally, Promega Corporation, a leader in providing innovative solutions and technical support to the life sciences industry, is currently constructing a new facility in Fitchburg, Wisconsin, that features CLT. This is the first large-scale commercial utilization of CLT in the United States using CLT manufactured in North America. As with any new building system, it is important for the design and construction community to have information on how CLT is installed and how it performs. The objectives of this research are twofold: (1) to document the CLT installation process with photography and video and (2) to install sensors in the CLT panels and collect data on in-service moisture and temperature conditions.
Online Access
Free
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Evaluating Hygrothermal Performance of Interlocking Cross-Laminated Timber Walls

https://research.thinkwood.com/en/permalink/catalogue804
Topic
Moisture
Material
CLT (Cross-Laminated Timber)
Application
Walls
Author
Glass, Samuel
Smith, Ryan
Organization
Forest Products Laboratory
Format
Report
Material
CLT (Cross-Laminated Timber)
Application
Walls
Topic
Moisture
Keywords
Climate
Building Envelope
Hygrothermal Performance
US
Interlocking CLT
Moisture
Research Status
In Progress
Summary
Unlike other solid wood panel systems, ICLT panels are manufactured without the use of adhesives or fasteners. Wood members are connected with tongue-andgroove joints within a given layer and with dovetail joints across layers. This reduces cost and allows ICLT panels to be disassembled at end of life to be repurposed in the building material supply chain. In addition, ICLT panels provide a means to utilize lumber from trees killed by mountain pine beetle. Durability is critical for sustainable construction, and avoidance of moisture accumulation in wood structural members is essential for long-term performance. Little work has been done specifically on hygrothermal performance of massive timber construction. The objective of this research is to identify building envelope design and construction practices for robust hygrothermal performance of ICLT walls in multiple U.S. climates.
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Hygrothermal Characterization and Modeling of Cross-Laminated Timber in the Building Envelope

https://research.thinkwood.com/en/permalink/catalogue2562
Year of Publication
2020
Topic
Moisture
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Building Envelope
Author
Kordziel, Steven
Glass, Samuel
Boardman, Charles
Munson, Robert
Zelinka, Samuel
Pei, Shiling
Tabares-Velasco, Paulo
Year of Publication
2020
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Building Envelope
Topic
Moisture
Design and Systems
Keywords
Building Envelope
Hygrothermal Modeling
Moisture Performance
Water Uptake
Hygric Redistribution
Research Status
Complete
Series
Building and Environment
Summary
Cross-laminated timber (CLT) is a type of mass timber panel used in floor, wall, and roof assemblies. An important consideration in design and construction of timber buildings is moisture durability. This study characterized the hygrothermal performance of CLT panels with laboratory measurements at multiple scales, field measurements, and modeling. The CLT panels consisted of five layers, four with spruce-pine-fir lumber and one with Douglas-fir lumber. Laboratory characterization involved measurements on small specimens that included material from only one or two layers and large specimens that included all five layers of the CLT panel. Water absorption was measured with panel specimens partially immersed in water, and a new method was developed where panels were exposed to ponded water on the top surface. This configuration gave a higher rate of water uptake than the partial immersion test. The rate of drying was much slower when the wetted surface was covered with an impermeable membrane. Measured hygrothermal properties were implemented in a one-dimensional transient hygrothermal model. Simulation of water uptake indicated that vapor diffusion had a significant contribution in parallel with liquid transport. A simple approximation for liquid transport coefficients, with identical coefficients for suction and redistribution, was adequate for simulating panel-scale wetting and drying. Finally, hygrothermal simulation of a CLT roof assembly that had been monitored in a companion field study showed agreement in most cases within the sensor uncertainty. Although the hygrothermal properties are particular to the wood species and CLT panels investigated here, the modeling approach is broadly applicable.
Online Access
Free
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Moisture Monitoring and Modeling of Mass-Timber Building Systems

https://research.thinkwood.com/en/permalink/catalogue1833
Year of Publication
2018
Topic
Moisture
Material
CLT (Cross-Laminated Timber)
Author
Kordziel, Steven
Glass, Samuel
Pei, Shiling
Zelinka, Samuel
Tabares-Velasco, Paulo
Organization
Forest Products Laboratory
Year of Publication
2018
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Moisture
Keywords
Moisture Monitoring
Hygrothermal Properties
High-Rise
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 20-23,2018. Seoul, Republic of Korea
Summary
The use of mass timber structural products in tall building applications (6–20 stories) is becoming more common around the world including North America. A potential concern is the environmental wetting of mass timber products during construction because such products may dry out more slowly than light-frame structural lumber, and wood, as an organic material, is susceptible to deterioration at elevated moisture contents. In order to better understand the moisture conditions present in high rise timber constructions, a long-term moisture monitoring program was implemented on an eight story, mixed-use, mass timber framed building in Portland, Oregon. The building was monitored with an array of moisture meters to track moisture content throughout the building’s construction and operation. This paper presents data covering a period just over one year starting from the manufacture of crosslaminated timber (CLT) panels. Hygrothermal properties of CLT samples of the same type used in the building were measured in the laboratory, and wetting and drying experiments on representative CLT samples were conducted. Simulated moisture contents using a one-dimensional hygrothermal model compared reasonably well with laboratory experiments and building site measurements.
Online Access
Free
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Moisture Monitoring Throughout the Construction and Occupancy of Mass Timber Builidings

https://research.thinkwood.com/en/permalink/catalogue1834
Year of Publication
2018
Topic
Moisture
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Author
Zelinka, Samuel
Glass, Samuel
Kordziel, Steven
Tabares-Velasco, Paulo
Pei, Shiling
Organization
Forest Products Laboratory
Publisher
University of Victoria
Year of Publication
2018
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Glulam (Glue-Laminated Timber)
Topic
Moisture
Keywords
Dimensional Instability
Microbial Attack
Fastener Corrosion
Cracking
Construction
Conference
International Conference on New Horizons in Green Civil Engineering
Research Status
Complete
Notes
April 25-27,2018. Victoria, Canada
Summary
This paper presents preliminary findings from an ongoing research program instrumenting CLT buildings to measure wood moisture content. An overview of the research program is presented along with data from first year of moisture monitoring in an 8-story building in Portland, Oregon. This project measures the wood moisture content throughout the construction cycle, including the fabrication, shipping, staging, and erection of the panels. These preliminary field measurements can help characterize moisture changes in CLT during construction and guide the construction of future CLT buildings.
Online Access
Free
Resource Link
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6 records – page 1 of 1.