Under Pressure: Wind Load Series Part 4
Home / Blog

Under Pressure: Wind Load Series Part 4

In the final post of our wind load series, we build on what we learned in previous discussions by delving into code bodies and agencies. The number of agencies, public and private, involved in the installation of siding can be complex. The graphic below shows a quick rundown of all the agencies and bureaucracies that weigh in on public safety.

ISO: International Standards Organization; they are the United Nations of codes. They encompass everything related to manufacturing, electrical, nuclear, quality, and more.

ANSI: is the American National Standards Institute and is the USA representative of ISO. They establish procedures that standard developers must follow when developing a new standard.

ASTM: American Society for Testing and Materials is a group of over 30,000 members who develop and publish 'voluntary consensus standards for a wide range of products, materials, systems and services.' (Wikipedia page of ASTM). There are individual standards for different materials and desired performance of each. There are hundreds of committees within ASTM, made up of industry experts, including testing agencies, manufacturers, consulting engineers, etc. Antitrust laws limit membership in these committees to no more than 50% of producers/manufacturers of the products affected by each standard. The standards are developed by their respective committee members. Though ASTM predates ANSI and ISO, it is closely related to both organizations and accreditation is reciprocal.

ASCE-SEI: American Society of Civil Engineers-Structural Engineers Institute develops standards pertaining to buildings and structures.

ICC: is the International Code Council, a consolidated building code that is widely accepted and acknowledged internationally; responsible for developing the International Building Code.

IBC: is the International Building Code. Published approximately every 3 years, the IBC is a model building code that is intended to be used ubiquitously. Originally it was intended to prevent local jurisdictions from developing their own standards and to prevent monopolies, and misuse of power. The building code aims to provide a standard for building construction for the safety of its users.

State Insurance Programs: are specific to each state. These government-run agencies' goal is their constituents' safety, especially in the case of natural disasters. They take into account weather patterns as well as topographic and geographic factors that are indigenous to their area. Some states, like Texas, have a special program requiring approval of a product's intended use in minute detail. Examples of similar programs include Florida Building Code (they have their own code, based on ICC) and California's WUI (a program developed by the State Fire Marshal to mitigate wild fire risk in new construction).

In a handy dandy table form'

The point here is that there are many variables and players in this game.

There are over 300 accredited testing lab agencies throughout the US and Canada. There are also many code evaluation entities, the most well-known being ICC-ES, which produces 'Evaluation Reports,' Warnock Hersey, and Underwriters Laboratories. There are new ones popping up, with the latest trend of major testing labs such as Intertek acquiring code evaluation certifications and providing this added service to their customers.

The test standards are pretty detailed, but there can also be room for interpretation by the lab manager and technicians. It is in the manufacturer's best interest to work closely with the testing agency to determine the best needs, assemblies, materials, and outcome of tests.

How could this lead us into potential trouble and nasty competition?

Well, the very manufacturers of these products ARE ALSO the members of these voluntary organizations. This makes sense, because we are experts in our field, but we also have a vested interest in seeing our products getting out to the marketplace with ease and maximum profitability.

It also gets tricky when standards are misinterpreted by the testing agencies, which are independent of ASTM. One testing lab's interpretation of the standard could prove catastrophic for a consumer.

Finally, companies/manufacturers must prove that they comply with the international building codes. ASTM, as we discussed previously, develops and publishes voluntary consensus technical standards. These standards are used by testing agencies (who are also members of ASTM). The reason for a technical standard is to have a uniform way for manufacturer's products to compare performance. These standards change over time as does the building code, so they must be revised, and manufacturers have to re-test their materials to make sure they meet the latest requirements and standards.

There is controversy with some manufacturers on when to re-test. The general rule of thumb is that any given test expires after 10 years. Another assumption is that any time the product undergoes a significant composition or manufacturing process change, it must undergo testing to ensure performance is the same or better than is listed in the published code evaluation report.

AC90 is an acceptance criteria published by the International Code Council Evaluation Service (ICC-ES)*. It is co-authored by its members, who also include manufacturers. AC90 pertains to mechanically-fastened fiber cement siding. It covers standards for fire, wind resistance, water penetration, etc.

Every time the building code is set to change, or when acceptance criteria are approaching expiration, the standard developers welcome opinions from their members.

Here is a link to ICC-ES AC90 call for public comments. In this instance the proposed revision to this acceptance criteria are shown stricken through. Competitors such as CertainTeed and James Hardie submitted proposed changes which led to changes in the final version of the acceptance criteria published later that year. As a result of the requests made by these manufacturers, the subsequently published AC90 included their changes.

In conclusion, manufacturers can take a very active role in the development of standards and policies that directly affect the installation of the product they sell. We at Nichiha strive to work closely with other industry experts, and even at times, our competitors to ensure our products will best serve our customers and global community. We have built relationships with officials in all of the government agencies mentioned above and are constantly looking to improve the performance of our product to go beyond even the latest published building codes.

Thank you so much for taking the time to read our Under Pressure Wind Load Series! I hope you have gained a better understanding of wind load requirements and testing. I would love to hear your thoughts and answer any questions you may have. Feel free to reach out to me in the comments section below.

*ICC-ES and ACs are not included in the above tables because they are not official agencies. AC90 is a criteria that ICC-ES publishes. ICC-ES is a private entity.

Read More:

Under Pressure: Wind Load Series Part 1
Under Pressure: Wind Load Series Part 2
Under Pressure: Wind Load Series Part 3

Categories: Performance
mail_outline link

This website uses cookies for analytics, personalised content and ads. By continuing to browse this site you agree to this use.

I Understand