One of the most basic principles of fire-rated assembly application is addressed in the Fire Resistance Design Manual (GA-600) with a simple phrase: “systems tested vertically shall not be permitted to be arbitrarily used in horizontal orientation.”

By now, almost anyone in the construction business who gets near a government contract has been made aware of the USGBC LEED point system.

With some exceptions, making a penetration in a gypsum board ceiling when it is not used to maintain a fire-resistance rating poses few problems. Unless the system is being used as a sound or smoke barrier, or as part of a seismic- or wind-resisting system, you pretty much can cut the hole, run the penetrating element, seal around the hole with some joint treatment, and walk away.

Section R703 of the International Residential Code and Chapter 14 of the International Building Code address exterior coverings and claddings for exterior walls including, but not limited to, EIFS, stucco (plaster) systems, and combustible and non-combustible siding products.

This column was originally run in October 2004 when home-owners were fixing up older homes in hopes of flipping them for a handsome profit. Now that the housing market is experiencing a correction in much of the country, more homeowners are staying put and sprucing up their homes with the intent of upgrading without having to sell in a soft market.

In last month’s column we discussed the basic parameters of finishing joints in fire-rated systems. To recap, joints in fire-rated gypsum board systems are typically required to be finished with tape and joint treatment, and fasteners are required to be spotted with joint treatment.

The purpose of this article is to explain the meaning of the ratings for fire resistive systems, such as one, two, three, and four hours, that are usually incorporated into model and jurisdictional building codes where appropriate.

The topic of this article was originally addressed in the September 2002 issue of Walls & Ceilings. Since then there have been a few changes that have prompted us to revisit the subject. Most notably, ASTM C1396, Standard Specification for Gypsum Board, which was introduced in 1999 as an umbrella standard that would combine and supersede nine separate gypsum product standards, has been fully adopted.

The use of gypsum board as a thermal barrier occasionally causes some misunderstanding. This seems to occur most often when an individual confuses the code requirements for a thermal barrier with the concepts behind an R-value, and he or she attempts to use R-values to resolve a thermal-barrier situation. Unfortunately, the two concepts, while somewhat linked scientifically, are altogether different and should not be viewed as equivalent or related ideas.

Our December 2006 column titled, “Using a Gypsum Board Membrane System for Fire Resistance” generated a couple of phone inquiries. The gist of both calls indicates that the column may have been a bit too brief in its explanation of membrane fire ratings.