Meet Fire Codes, Cut Costs

meet fire codes, cut costs

A new technology is helping lower the cost of meeting fire codes.

There’s now new technology to help builders confidently meet fire code at a lower cost than previously possible. The key is reducing the amount of gypsum needed to achieve code compliance. Gypsum panels have been used in wall assemblies for more than a century. In addition, gypsum shaft liner panels have long been a key component of code-compliant walls used in townhome separation walls. But shaft liner wall applications require numerous metal components, plus a crew well-versed in the methods of installing them.

Advances in fire-resistant OSB—such as LP FlameBlock Fire-Rated OSB Sheathing—have resulted in a two-hour fire-rated wall assembly that is easier to install than those using shaft wall liner.

Cost-Effective Alternative

fire-rated wall

This UL-listed wall assembly uses fire-rated OSB. The panels cut easily and no special parts are needed. Best of all, the U350 assembly is more than 200 pounds lighter per 4′ x 8′ area than a U375 or similar wall assembly using shaft wall liner.

Although shaft liner walls have been widely used to meet fire codes for decades, they pose many challenges. One is weight: a 4´ x 8´ section of shaft wall can weigh more than 630 pounds. Traditional shaft wall liner is often difficult to cut and must be augmented by numerous metal parts (including C-channels, H-studs and breakaway clips).
There’s now a UL-listed wall assembly that uses fire-rated OSB to solve these problems. The panels cut easily and no special parts are needed. Best of all, the U350 assembly is more than 200 pounds lighter per 4´ x 8´ area than a U375 or similar wall assembly using shaft wall liner.

Wall Assemblies in Action

Volunteers from Habitat for Humanity of New Castle County (Delaware) recently used U350 wall assemblies to build area separation walls at nine single-family attached townhomes. Many of the volunteers lacked building expertise and weren’t able to install shaft liner wall assemblies. However, they were able to assemble and place the U350 wall assemblies on the ground, then raise them up for easy installation.
“Our volunteers range from people who have never touched a hammer to semi-professional framers,” says Sean Allen, the organization’s director of construction and real estate. “The typical partition wall uses a heavier material, and it’s cumbersome and poses safety issues for our volunteers.”

Because the U350 wall assembly using fire-resistant OSB eliminates the heavy, one-inch-thick gypsum and additional parts needed for an assembly using shaft wall liner, the volunteers were able to construct the walls much faster.

“I would say the assemblies were built probably a month or two faster than shaft wall assemblies would have taken,” says Allen. “If this job had used production builders, I can see how this assembly would greatly affect the cost of a build because of time and labor savings.” Although the U350 wall assembly is not yet common in New Castle County, the code officials saw that it was a 2-hour rated UL-listed assembly for partition walls and had no problem approving it.

Solving Labor and Material Costs

Wall assemblies like U350 that use fire-resistant OSB are helping architects and builders meet fire code while lowering both labor and material costs compared to assemblies utilizing shaft wall liner. It’s the ideal way to balance building safety and budget issues.
For more information on this product solution, download the pdf here.

Sarah Caperton is OSB Product Manager at Louisiana-Pacific Corporation.