AboutPaul S. Brown, AIA Expertise How to work with an Architect. What to expect for design fees. What services are normally
included; what are not included? How do I find an Architect in my area? Why do I need an
Architect? How to be clear about your space needs. Why time must be managed properly.
Experience 24 years involvement in the practice of Architecture, including some teaching experience. Most of my work has been within the employment of various firms, but I have also done some small-scale projects on my own.
Particular interests include Environmental Design, "Green" Design, and Appropriate Technologies. LEED (TM) Accredited Professional.
I have some specific experience with Historic Preservation, Medical Facilities, Commercial Interiors, and Public School projects.
Education: Bachelor of Environmental Design Degree (Architecture), 1978, Miami University in Ohio. I am registered to practice professionally in the states of Massachusetts and Maine.
Question (1) If I want to clad some decorative lightweight cement panels over a 2 hour
rated wall, what would be the appropriate way w/o affecting the fire rating? If I
fasten furring channels, I am penetrating the rating wall?
(2) how do people install light fixture on fire rated wall and maintain it's rating?
Answer Hi Siuling:
(1) Technically, the 2-hour wall must not deviate from it's very specific UL-listed testing assembly configuration. Each tested wall assembly must be constructed exactly as specified in the U.L. manual, and any deviation from that means that it does not conform. So, the right way to erect your decorative panels, would be to construct an entirely separate metal stud wall in front of the 2-hour wall, independent and without fastening to the existing 2-hour wall.
As a practical matter, however, I would encourage you to discuss this with your local building official. If the new cement panels are non-combustible, and if you use metal furring channels, then it seem like a very reasonable thing to allow you to proceed in this way; in effect, perhaps, increasing the fire-resistance rating of the overall wall assembly by adding another fire-resistive layer. Technically, it would not be a listed assembly; but from a practical point of view I would be very surprised if the local official would not allow you to proceed this way.
(2) the U.L. Assembly manual does allow, in some cases, recessed electrical boxes in listed assemblies; it requires additional layers of fire-resistive materials behind the box, and other specific measures. If the wall is already up, then it would be best to mount your light using a surface-mounted backbox and raceway .... not very attractive, unfortunately.
I hope that helps; good luck with your project.
PB
