Our Products - Post & Beam Construction - Features & Benefits
An effective way to strengthen P&B structures using Norbord OSB
P&B construction is celebrated for its elegance and timeless beauty that blends with the natural landscapes of Japan. With their beautiful rooflines, Japanese P&B buildings were traditionally supported by a skeletal structure of posts and beams. Diagonal bracing was also used to provide the lateral stability of buildings.
The introduction of Norbord OSB sheathing adds a new dimension to structural performance, particularly in wall framing where it complements the cross braces traditionally employed in walls to resist in-plane shear forces generated by earthquakes and windstorms. The use of Norbord OSB greatly increases structural performance and is more effective at withstanding natural disasters.
Raising the standard
In recent years the Japanese government has pressed for the construction of “long-life quality housing”. The goal is enhanced performance through higher levels of structural resistance and durability. The need for buildings with higher performance capabilities has been underscored in the aftermath of several recent large-scale natural disasters.
The superior structural performance of Norbord OSB and the range of dimensions in which it is available enable it to meet a variety of sheathing demands within the Japanese P&B construction industry. Norbord OSB is the ideal choice for builders seeking superior strength and reliability in roof, wall and floor structural assemblies in P&B construction.
Our OSB is found in single-family homes and multi-family apartment buildings as well as in non-residential buildings such as elderly care facilities, schools and retail shops.
OSB dimensions and span ratings for Post & Beam construction
|Applications||JAS Grade Class||Nominal Thickness (mm)||Nominal Width (mm)||Nominal Length (mm)||Maximum Span (mm)||Nail Type / Nail Spacing (mm)|
|Loadbearing walls (Strength axis parallel to supports)1||4||9.0
|Roof Sheeting2 (Strength axis perpendlcular to supports)||3||11.0
|Floor Sheeting (Strength axis perpendlcular to supports)||2||15.0||910||1820||455|
- Panels can also be installed with the strength axis perpendicular to supports. For more info, consult APA-The Engineered Wood Association.
- T&G panels are available for faster roof installation.
- Panels in other dimensions are also available upon request.
Shake table test of three-storey post & beam house at the Public Works Research Institute (PWRI), Tsukuba, Japan. The house comprises a Canada Tsuga post & beam frame, sheathed with Norbord (formerly Ainsworth) OSB. The three main tests, conducted in September 2008, recreated the 1995 Great Hanshin earthquake JMA station record, with increasing levels of intensity of 1.0, 1.5 and 2.0 times the earthquake actual signal without repairing the building between tests. The building survived the three earthquakes with minimal structural damage after the two first tests. The third test with a peak ground acceleration greater than 1.7 times gravity (PGA >1.7 g) resulted in heavy structural damage in the ground floor but no collapse.
Video courtesy: Dr. Naohito Kawai, Kogakuin University
M. Li, F. Lam, R.O. Foschi, S. Nakajima and T. Nakagawa: J Wood Sci (2012) 58: 20–30.
The shake table test was conducted under the joint project (project leader: Dr. Frank Lam) between University of British Columbia and Building Research Institute in Japan.
New demand for insulated homes
Japan’s 2×4 construction system has proven largely successful in withstanding natural disasters. The addition of OSB sheathing also provides a more comfortable living environment to residents, allowing for insulation in wall, roof and floor cavities. The P&B industry has taken note. Demand for energy-conserving insulated buildings has driven an increase in OSB panel use by builders. Insulated buildings offer cost-efficient, more comfortable residences that shield occupants from hot, humid summers and cold, dry winters.
Environmentally friendly – wood is good
Life cycle assessments consistently show that wood products have clear environmental advantages over other building materials. Wood buildings are associated with lower greenhouse gas emissions including carbon dioxide, less air pollution, less solid waste and less use of resources. Wood also requires less energy to extract, convert into products, and incorporate into the finished structure.