This project aims to support the construction of tall wood buildings by identifying encapsulation methods that provide adequate protection of mass timber elements; the intention is that these methods could potentially be applied to mass timber elements so that the overall assembly could achive a 2 h fire resistance rating.
This literature review aims to provide a general picture of retrofit needs, markets, and commonly used strategies and measures to reduce building energy consumption, and is primarily focused on energy retrofit of the building envelope. Improving airtightness and thermal performance are the two key aspects for improving energy performance of the building envelope and subsequently reducing the energy required for space heating or cooling. This report focuses on the retrofit of single family houses and wood-frame buildings and covers potential use of wood-based systems in retrofitting the building envelope of concrete and steel buildings.
Air sealing is typically the first step and also one of the most cost-effective measures to improving energy performance of the building envelope. Airtightness can be achieved through sealing gaps in the existing air barrier, such as polyethylene or drywall, depending on the air barrier approach; or often more effectively, through installing a new air barrier, such as an airtight exterior sheathing membrane or continuous exterior insulation during retrofit. Interface detailing is always important to achieve continuity and effectiveness of an air barrier. For an airtight building, mechanical ventilation is needed to ensure good indoor air quality and heat recovery ventilators are typically required for an energy efficient building.
Improving thermal resistance of the building envelope is the other key strategy to improve building energy efficiency during retrofit. This can be achieved by: 1. blowing or injecting insulation into an existing wall or a roof; 2. building extra framing, for example, by creating double-stud exterior walls to accommodate more thermal insulation; or, 3. by installing continuous insulation, typically on the exterior. Adding exterior insulation is a major solution to improving thermal performance of the building envelope, particularly for large buildings. When highly insulated building envelope assemblies are built, more attention is required to ensure good moisture performance. An increased level of thermal insulation generally increases moisture risk due to increased vapour condensation potential but reduced drying ability. Adding exterior insulation can make exterior structural components warmer and consequently reduce vapour condensation risk in a heating climate. However, the vapour permeance of exterior insulation may also affect the drying ability and should be taken into account in design.
Overall energy retrofit remains a tremendous potential market since the majority of existing buildings were built prior to implementation of any energy requirement and have large room available for improving energy performance. However, significant barriers exist, mostly associated with retrofit cost. Improving energy performance of the building envelope typically has a long payback time depending on the building, climate, target performance, and measures taken. Use of wood-based products during energy retrofit also needs to be further identified and developed.
In this project, a conceptual but realistic 20-storey building of hybrid construction incorporating massive timber panels and other structural materials was identified. The project team, consisting of three practicing consultants and 6 graduate student and post-doctoral researchers from NEWBuildS, undertook an analysis and engineering design of the demonstration building. An advisory group that includes FPInnovations scientists, NEWBuildS supervisors of the graduate students and Post Doctoral Fellows, provides technical support to the project team. The performance attributes addressed in the project were structural performance under seismic and wind load, fire resistance and building envelope. . This publication documents the analysis and design of the demonstration building, and identifies technical issues that require further study.
The superior fire performance of timbers can be attributed to the charring effect of wood. As wood members are exposed to fire and the wood begins to burn, a char layer is formed. The char layer acts as an insulator and protects the core of the wood sect...
Both the BCBC and the NBCC are objective_based codes whose provisions are deemed to be acceptable solutions. Alternative solutions are permitted; however, they must be demonstrated to provide a level of performance equivalent to that of the acceptabl...
Vertical gypsum fire separation walls that have fire-resistive ratings evaluated in accordance with a recognized standard are permitted for use in building construction. When approved doors are inserted in such walls, the details must be presented for consideration as an “alternative solution”.
This guide is based on observations of two CAN/ULC S101 (ULC, 2007) tests on gypsum fire separation walls with S104 (ULC, 2010) approved closure penetrations. The guidance is intended to direct the designer’s attention to potential issues that might impact the performance of a closure penetration in a gypsum separation wall that use a thick wood-based sheathing (i.e. combustible) for carrying the weight of the fire door assembly. General guidance is provided on sizing the sheathing and the need for protecting the sheathing from fire, yet permitting the assembly to accommodate building movements in-service.
The purpose of this guide is to recommend considerations when designing the interface between a fire door (closure penetration) in proprietary gypsum separation walls. These considerations form only part of the alternative solution that will need to be presented to the AHJ for approval.
Although details are provided in Appendix VI to illustrate a possible solution, it is the responsibility of the designer to understand how the design is expected to perform. The guide discusses three scenarios to assist the designer in formulating an appropriate solution. These are performance under an extreme fire; performance under a limited fire; and performance under normal (non-fire) service conditions that may include high wind or high seismic event.
The North American product standard for performance-rated cross-laminated timber (CLT), ANSI/APA PRG 320, was published in 2012. The standard recognizes the use of all major Canadian and US softwood species groups for CLT manufacturing and provides design...