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Posted

...from my inspector blog

Building Code Thoughts

Building codes are developed by independent non-governmental organizations that survive mainly by sale of their copyrighted product.

The United States has seen a consolidation of those organizations to two main ones, NFPA and ICC.

Both publish comprehensive sets of building codes, but they dominate region by region in different code areas. In Georgia, for example, the state officially adopts different parts of the two organizations? published products. NFPA's electric code and "life safety" code, and ICC's building, plumbing, and mechanical codes.

Both codes rely heavily by reference on sets of industry standards, which are developed as well by private, non-governmental trade and industry groups that ride herd on the stream of building products in terms of safety and performance.

In any building put together today from products selected from current suppliers there is a very high certainty that the building products have been tested and listed for the use they are put to.

The trouble with building quality and performance usually lies in wrong uses of materials and incorrect installation.

Structural requirements in codes are based on fairly limited sets of assumed conditions and are presented in sets of tables and graphic illustrations.

Installation requirements are also minimal and every section thereof refers to manufacturers' instructions.

The private and ostensibly non-political development of all the codes and their referenced standards offers some assurance that building codes are outside the arena of politics, but there are plenty of political pressures behind the scenes, especially regarding new product introduction.

Some products have been "rushed" to market, such as a composite siding made by Louisiana Pacific that was introduced in the early '80's and was halted a few years later. The product had begun to fail as soon as the early installations' paint began to age a little. It proved unable to bear the effects of weather unless well encapsulated by paint coating.

Almost all building products are laden with sets of installation instructions that describe their performance value in terms of the installer's adherence to those instructions. Building codes that describe procedure always defer to manufacturer's instructions.

Inspection of existing buildings has value precisely because many if not most building products that clear the review and listing process to make it onto the market are incorrectly specified and/or installed.

People performing on- site work display a surprising range of skills in application and installation. When I worked for a local code authority I regularly found contractors using wrong materials for the use and botching installation of components, completely ignoring instructions printed boldly on product packaging or stickered brightly on product surfaces.

Whether codes were in force or enforced during a building's erection is a moot point, but codes language does provide good context for identifying problems.

Like the pirate Captain Barbossa said, "...the Code is more what you'd call "guidelines" than actual rules..."

Posted

I should point out that LP siding was one of dozens of siding products that were rushed to market in the '80s, almost all of which failed. The LP product was unique in that they never actually halted production, but continued to refine it. They still make it to this day and it's matured into a decent siding product that hardly anyone in the USA will use because of its association with failure through the '90s.

It might also be interesting to ruminate on the difference between performance-based codes and prescriptive codes; two fundamentally different approaches to the code making process.

Posted

In our part of the world, NFPA codes and ICC codes work together fairly well. I haven't ever seen a non-federal jurisdiction use NFPA's life safety code in lieu of the ICC material that covers that subject. The only NFPA code that California directly adopts is the National Electrical Code. Some of the other NFPA codes and standards are adopted through their reference in an ICC code, and other NFPA codes might be used for guidance in gray areas (particularly mechanical design).

The IAPMO codes make up the third leg of the tripod, and these can be a problem. There are many ways in which they are not compatible with ICC codes. More to the point of your article, they are also highly competitive with ICC in terms of product evaluation and certification.

I also see a big difference between projects constructed using prescriptive codes (primarily single-family residential) and those that require design. Once design is required, ASCE 7 becomes the primary source document, and the local code is simply the door it walks through to be legally empowered as the basis for design.

Posted
The private and ostensibly non-political development of all the codes and their referenced standards offers some assurance that building codes are outside the arena of politics, but there are plenty of political pressures behind the scenes, especially regarding new product introduction.

Yeah. That part. I wonder a lot about that.

I get jealous working in the code bubble that's Chicago. You guys can buy a book with the info. We got 167 different municipalities, all with their own variants. There's even one suburb where the AHJ lobbied to make NMC legal, built his own house, then lobbied to switch it back to EMT. Stuff like that. Can o' worms.

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