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Bracing Panels
BC Building Code 2024 substantially revises the Part 9 bracing requirements for small homes and buildings and expands the list of acceptable braced wall panel types. Is there an equivalent wall type for the previous bracing requirement?
The bracing panels in the BCBC 2018 (equivalent to the NBC 2020) can be broadly described as either 11 mm plywood or OSB sheathing on 400 mm on centre (o.c.) studs or 12.5 mm plywood or OSB sheathing on 600 mm o.c. studs, with gypsum board finish on the interior face and typical fastening. The bracing panels in the BCBC 2024 (equivalent to the upcoming NBC 2025 provisions) can be sheathed with plywood or OSB (designated WSP), gypsum alone (designated GWB), or diagonal lumber boards (designated DWB).
Given that the 2018 bracing options did not require blocking of horizontal sheathing edges, the only option for 2024 equivalency for the same construction would be WSP-A. WSP-A is defined as 9.5 mm sheathing on 400 mm o.c. studs with gypsum on the reverse. The sheathing thickness is more similar to WSP-B, however that 2024 bracing type requires blocking and therefore would be much stronger than an unblocked equivalent.
How can one determine the Fire Resistance Rating (FRR) and Sound Transmission Coefficient (STC) ratings for wood stud shear walls that include plywood on one or both sides and are finished with gypsum? To achieve a 1-hour rating, is it possible to use an existing tested gypsum assembly to meet both FRR and STC requirements and simply add plywood without affecting the ratings? Is there a better way to determine the FRR and STC ratings in this scenario?
Additional information on the new bracing provisions:
CWC Wind and Seismic Calculator
BC Housing Illustrated Guide
(contributed to by CWC)
(contributed to by CWC)
The calculator is a free web tool that determines the required length of bracing in a wall line based on simple inputs for building geometry and site conditions. In addition, the tool includes numerous pop-ups that elaborate on and explain the relevant clauses from NBC 2025.
ASK AN EXPERT
Title
BC Building Code 2024 substantially revises the Part 9 bracing requirements for small homes and buildings and expands the list of acceptable braced wall panel types. Is there an equivalent wall type for the previous bracing requirement?
Real wood continues to outperform composite alternatives when it comes to durability, sustainability, comfort, and long-term value.
Certain wood species commonly used for decking—such as redwood and cedar—are naturally resistant to rot and insects. Other wood species benefit from pressure treatment which extends longevity and enhances performance in outdoor environments. Structurally, wood’s natural composition of strong cellulose fibres and lignin gives it exceptional tensile and flexural strength, allowing it to resist stress and distribute load effectively over time.
From an environmental standpoint, wood offers significant advantages. It is a natural, renewable material with the lowest embodied energy of any decking option. Wood stores carbon throughout its lifespan, emits fewer greenhouse gases, and can be reused, repurposed, or recycled at end of life. By contrast, composite materials—especially those made with virgin plastics—tend to have a higher environmental impact and limited recyclability.
Wood also excels in comfort and safety. Unlike composite surfaces, which can become hot in the sun and slippery in wet or humid conditions, real wood remains cooler underfoot and provides better traction. This makes it a more pleasant and practical surface, especially in variable climates.
Aesthetically, real wood offers natural grain, variation, and warmth that synthetic materials can’t replicate. Each board is unique, contributing to the visual richness of an outdoor space. And when comparing costs, real wood—particularly pressure-treated or cedar options—remains significantly more affordable than most composite products.
How can one determine the Fire Resistance Rating (FRR) and Sound Transmission Coefficient (STC) ratings for wood stud shear walls that include plywood on one or both sides and are finished with gypsum? To achieve a 1-hour rating, is it possible to use an existing tested gypsum assembly to meet both FRR and STC requirements and simply add plywood without affecting the ratings? Is there a better way to determine the FRR and STC ratings in this scenario?
For a deeper look at the performance, sustainability, and comfort advantages of wood decking, read the full article “Real Wood vs. Composite Decking” by Mauraine Bos and Sandeep S. Nair.
ASK AN EXPERT
Bracing Panels
I’ve heard composite decking is more durable and eco-friendly than real wood.
Is that true?
Real wood continues to outperform composite alternatives when it comes to durability, sustainability, comfort, and long-term value.
The bracing panels in the BCBC 2018 (equivalent to the NBC 2020) can be broadly described as either 11 mm plywood or OSB sheathing on 400 mm on centre (o.c.) studs or 12.5 mm plywood or OSB sheathing on 600 mm o.c. studs, with gypsum board finish on the interior face and typical fastening. The bracing panels in the BCBC 2024 (equivalent to the upcoming NBC 2025 provisions) can be sheathed with plywood or OSB (designated WSP), gypsum alone (designated GWB), or diagonal lumber boards (designated DWB).
Given that the 2018 bracing options did not require blocking of horizontal sheathing edges, the only option for 2024 equivalency for the same construction would be WSP-A. WSP-A is defined as 9.5 mm sheathing on 400 mm o.c. studs with gypsum on the reverse. The sheathing thickness is more similar to WSP-B, however that 2024 bracing type requires blocking and therefore would be much stronger than an unblocked equivalent.
BC Housing Illustrated Guide
(contributed to by CWC)
(contributed to by CWC)
ASK AN EXPERT
Title
I’ve heard composite decking is more durable and eco-friendly than real wood.
Is that true?
Real wood continues to outperform composite alternatives when it comes to durability, sustainability, comfort, and long-term value.
Certain wood species commonly used for decking—such as redwood and cedar—are naturally resistant to rot and insects. Other wood species benefit from pressure treatment which extends longevity and enhances performance in outdoor environments. Structurally, wood’s natural composition of strong cellulose fibres and lignin gives it exceptional tensile and flexural strength, allowing it to resist stress and distribute load effectively over time.
From an environmental standpoint, wood offers significant advantages. It is a natural, renewable material with the lowest embodied energy of any decking option. Wood stores carbon throughout its lifespan, emits fewer greenhouse gases, and can be reused, repurposed, or recycled at end of life. By contrast, composite materials—especially those made with virgin plastics—tend to have a higher environmental impact and limited recyclability.
Wood also excels in comfort and safety. Unlike composite surfaces, which can become hot in the sun and slippery in wet or humid conditions, real wood remains cooler underfoot and provides better traction. This makes it a more pleasant and practical surface, especially in variable climates.
Aesthetically, real wood offers natural grain, variation, and warmth that synthetic materials can’t replicate. Each board is unique, contributing to the visual richness of an outdoor space. And when comparing costs, real wood—particularly pressure-treated or cedar options—remains significantly more affordable than most composite products.
For a deeper look at the performance, sustainability, and comfort advantages of wood decking, read the full article “Real Wood vs. Composite Decking” by Mauraine Bos and Sandeep S. Nair.