SBCA & SBCRI Issue Investigative Report Series
Originally published by: SBCRI-SBCA Investigative Reports — October 15, 2015
The following article was produced and published by the source linked to above, who is solely responsible for its content. SBC Magazine is publishing this story to raise awareness of information publicly available online and does not verify the accuracy of the author’s claims. As a consequence, SBC cannot vouch for the validity of any facts, claims or opinions made in the article.
SBCRI's goal is to ask: Is this true or not? SBCRI provides the facts and lets the reader decide.
SBCA believes it is important for professionals in the building design and construction industry to have a transparent understanding of the properties of the materials they use to construct buildings. Specifically, they should know a material’s design properties and its ability to resist loads in real-world applications. Certainly, end users who buy or rely on these products expect accurate assumptions regarding material properties through:
- Structural design models that are calibrated to testing
- Building codes
The market assumes that the building code provides a conservative treatment of the testing and codifies a reasonable minimum performance requirement. Since code language is adopted into law, everyone in the construction industry is obligated to abide by it. Therefore, the accuracy of the IRC, IBC and Wood Frame Construction Manual (WFCM) is vital. Inaccurate assumptions in these publications can easily have unintended factor-of-safety consequences and will also have a significant impact on the competitive market.
The following SBC Industry News: Special Edition articles are the first in a series of SBCRI-SBCA reports on topics that concern SBCRI and affect SBCA members. The goal of these reports is to focus on a single issue and present the facts surrounding it as concisely as possible. SBCRI has found that change is hard and changing long-standing tradition is even harder.
The goals of SBCRI-SBCA reports are as follows:
- Place what we know in the public domain, and solicit test reports and analysis that can provide additional information to enhance or correct our knowledge.
- Allow the engineering community to make better judgments as they design structures by providing information for a more complete understanding of an issue.
- Allow the buyers of the products and the engineering community to define product performance expectations and push for precise and reliable design values to be published for the individual products supplied to the market.
- Allow the building code community to use this information to make changes to the building code locally, regionally and nationally. The enforcers of the building code are best situated to ensure the code is correct.
- Allow reliance on the derivation of design values that the code has established, which have been codified into law through codes and standards (e.g., IRC, WFCM, IBC, SDPWS, etc.), for equivalent performance assessment. In other words, if 450=840 for OSB via the law, 450=840 for all competitors of OSB. The code does not say nor is there any data that says 450=840 is exclusively an OSB property. APA certainly has not provided any data to the public that says that this is the case, nor have they helped to make the factors that caused this to be the case in the IRC transparent. (see the Crandell/Martin paper on this topic).
- Make transparent, as adopted into law, any market inequities that established code design values created through testing and analysis of real-world building performance. This includes comparative analysis of code provisions and related test data, to provide support for equivalency assessments to an intended end use application.
- Foster innovation in the building design and construction environment.
- Provide facts in the public domain that are easy to access, reliable and transparent. If done well this will help provide much deeper and better understanding. This will also help in all potential litigation events, the goal being that outcomes are more justifiable and fair.
It is increasingly clear to SBCA that reliable and safe building performance is predicated upon accurate design properties, engineering precision and a complete understanding of the raw material engineering considerations needed for successful application or installation. Suppliers of products to SBCA members are responsible for ensuring that there is easy access to this understanding, along with any relevant factors that should be considered in that design process.
It is in the best interest of SBCA members and the construction industry at large that engineering, and thus, construction, be entirely based on tested and accurate raw material load resistance data. This will not only improve construction performance that is based on engineering (i.e. joists, rafters, trusses, shear walls, etc.) and is therefore safe, but also allow for better engineering-based judgments and further engineering innovation.