Horizontal Shaftwall and Duct
I-Stud Cavity Shaftwall Systems can be erected horizontally and used as economical fire resistive assemblies for corridor ceilings, stair soffits, and protection for mechanical ducts.
The I-Stud Cavity Shaftwall System for Horizontal Duct Protection consists of I-Studs 24" o.c. with 1" Fire-Shield Shaftliner panels inserted in the stud tabs, and three layers of 1/2" Fire-Shield® C Gypsum Board attached to the stud flanges opposite the Shaftliner panels. This System provides fire protection for mechanical ducts and has been tested from both sides.
Two layers of 1/2" Fire-Shield C Gypsum Board attached to the stud flanges opposite the Shaftliner provide 2-hour fire protection when used as a corridor ceiling or stair soffit.*
Similarly, single layer 5/8" Fire-Shield or Fire-Shield C Gypsum Board attached to the stud flanges opposite the Shaftliner panels provide 1-hour fire protection when used as a corridor ceiling or stair soffit.*
I-Stud Cavity Shaftwall Systems erected horizontally for corridor ceilings or stair soffits are designed to carry their own deadweight only, and should not be used where there is access to an attic or loft above, or any probability of storage.
In addition, the 2-hour horizontal duct protection system is not designed to carry live loads or the weight of the mechanical ducting it is protecting.
For more technical data on the maximum allowable horizontal spans of each system, please refer to the Product Literature found above in the Products Links box.
*See ICBO Evaluation Services, inc. Evaluation Report No. 3579 for allowable values and/or conditions of use concerning material presented in this document. It's subject to re-examinations, revisions, and possible cancellations.