A head of wall joint is one of the firestop systems. It is a linear gap between the top of a wall assembly and the bottom of a floor or roof assembly. This firestop system is one of the U.S. model building codes require head-of-wall fire joint systems. It is assembled the top of fire rated wall and the underside of fire rated floor or roof assemblies. A fire stopping system is installed to protect these joints. The wall and floor and roof construction allowed by a system is specified in the head-of-wall firestopping listing.
Requirements Of Head Of Wall Joint
The minimum requirements in this section of the listings should match the field conditions. These requirements are the following below:
- It ensures that the fire protection material on the floor and roof assembly or beam and joist in the field condition is listed in the system. Now, head-of-wall fire-stopping systems at Underwriters Laboratories are available for only cementitious fire-resistive materials. There are no head-of-wall firestop listings and no permitting the use of mineral fiber fireproofing.
- It is secure the actual wall assembly in the field condition is accommodated by the system. Shaft walls that are installed from one side of the wall and incorporate a gypsum liner or core board are different than standard steel stud walls and should be specifically listed in the system.
Head Of Wall Joint Installation Procedure
- A condition that is prevalent in most buildings is a rated wall assembly that meets a non-rated roof assembly. Finding a third party listed system for this condition is unfortunately not possible.
- Installation of the fire stopping materials into the head of wall joint is provided in the system. If mineral wool is a component of the system, ensure the type of mineral wool and the density installed are listed in the system.
- Secondly, ensure the mineral wool is compressed into the joint as indicated by the system.
- Head-of-wall firestopping system selection and installation can be made simple if the tested listing is understood and utilized as a guide for proper installation.
- If there are specific questions about a third party laboratory listed head-of-wall fire stopping system, the third party laboratory or manufacturer of the fire stopping materials listed in the listing should be contacted for clarification.
- Proper installation of fire stopping systems the first time can reduce long-term applicator expense and maintains a high level of life safety for building occupants.