Skip header and navigation

2 records – page 1 of 1.

Hygrothermal Performance of Cross-Laminated Timber Wall Assemblies with Built-In Moisture: Field Measurements and Simulations

https://research.thinkwood.com/en/permalink/catalogue273
Year of Publication
2014
Topic
Serviceability
Moisture
Material
CLT (Cross-Laminated Timber)
Application
Walls
Wood Building Systems
Author
McClung, Ruth
Ge, Hua
Straube, John
Wang, Jieying
Organization
Building and Environment
Publisher
ScienceDirect
Year of Publication
2014
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Walls
Wood Building Systems
Topic
Serviceability
Moisture
Keywords
Drying
Hygrothermal
Moisture Content
Research Status
Complete
Series
Building and Environment
Summary
Cross-laminated timber (CLT) panels have potential market in North America for building mid-rise or even taller structures due to their good structural and fire safety performance, light weight, and prefabricated nature. However, to ensure long-term durability when used in building enclosures, the hygrothermal performance of CLT wall assemblies needs to be evaluated in terms of wetting and drying potential. A test wall consisting of sixteen 0.6 m by 0.6 m CLT panels made of five different wood species (or species groups) and four different wall assemblies was constructed. The CLT panels were initially wetted with the moisture content (MC) in the surface layers approaching or exceeding 30%, and monitored for MCs and temperatures at different depths over one year in a building envelope test facility located in Waterloo, Ontario. The drying behaviour of these panels was analysed and the measured MCs over time were compared to simulation results using a commercial hygrothermal program. This field study showed that most of the CLT panels dried to below 26% within one month except for CLT walls with a low-permeance interior membrane, which indicated that none of the CLT walls would likely remain at a high MC level long enough to initiate decay under the conditions tested. The simulation results generally agree well with the field data at MCs below 26%. However, it was found that the hygrothermal simulation program tended to overestimate the MC in the centre of the panels by up to 5e10%, and simulated MCs at locations deep into the CLT panels were not as responsive to changes in ambient conditions, as the measurements indicated for assemblies with high exterior permeance.
Online Access
Free
Resource Link
Less detail

Wetting and Drying Performance of Cross-Laminated Timber Related to On-Site Moisture Protections: Field Measurements and Hygrothermal Simulations

https://research.thinkwood.com/en/permalink/catalogue2711
Year of Publication
2020
Topic
Moisture
Site Construction Management
Material
CLT (Cross-Laminated Timber)
Author
Wang, Lin
Wang, Jieying
Ge, Hua
Organization
Concordia University
FPInnovations
Publisher
EDP Sciences
Year of Publication
2020
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Topic
Moisture
Site Construction Management
Keywords
Hygrothermal
Simulation
Hygrothermal Models
On-site Wetting
Conference
Nordic Symposium on Building Physics
Research Status
Complete
Summary
Cross-laminated timber (CLT) panels are increasingly used in mid-rise buildings or even taller structures in North America. However, prolonged exposure to moisture during construction and in service is a durability concern for most wood products including CLT. To investigate practical solutions for reducing on-site wetting of mass timber construction, CLT specimens with a range of moisture protection measures, in six groups were tested in the backyard of FPInnovations’ Vancouver laboratory from Oct. 2017 to Jan. 2018. This study investigates the wetting and drying behaviours of the tested CLT specimens through 2-D hygrothermal simulations. The simulations are performed for base specimens (no protection measures) of group 1 (without joint or plywood spline) and group 2 (with a butt joint and plywood spline). For group 1, three data sources of material properties are used to create the models, and the data that led to the best agreement between simulations and measurement are used for creating the models of group 2. For group 2, two types of hygrothermal models are created with or without considering the differences in water absorption between the transverse and the longitudinal grain orientations. In addition, rain penetration is taken into account for the joint area. It is found that the model with considering the differences between transverse and longitudinal grain orientations shows a better agreement than that without considering such differences.
Online Access
Free
Resource Link
Less detail