Q&A: Fire Resistance-Rated Ceiling Designs Supporting Grade I Insulation Installation

Q: Are there UL fire resistance rated roof-ceiling designs that can meet Grade I insulation quality standards when an attic space is available?

A: Yes, fire-rated roof-ceiling assemblies that include resilient channels and loose-fill insulation are a common option that allow insulation to rest directly against the gypsum board air-barrier without gaps and voids, thereby meeting Grade I standards.

To find these designs, follow this step-by-step process:

1. On Product iQ, scroll down to the section entitled “IQ PLUS SEARCH TOOLS” and click on “Building Materials, Systems and Installation Codes,” then click on “Fire Rated Roofs, Walls, Floors, Beams and Columns.”
2. In the menus on the left, select or type in the following:
   • Keyword – Loose Fill Material
   • Fire-Rated Design Details Assembly Type – select Roof-Ceiling
   • Protection Type – select Gypsum Board
   • Additional Filter – select Steel Structure or Wood Structure appropriately
3. After entering the above, click “Search” to the right of Keyword. To view a preview of the drawing of each design, click the dropdown “Display” and select “Images.” To view the design, click on the link that begins with “BXUV.” Within each design, look for the items entitled “Loose Fill Material.”

Q: For buildings without an accessible attic space, as in some townhouse or multifamily flat roof assemblies, Are there UL fire resistance rated roof-ceiling designs that can easily meet Grade I insulation quality standards?

A: Yes, rated ceiling assemblies with a suspended wire mesh or netting allow loose fill insulation to be installed before gypsum board is hung. These are a good option for meeting Grade I insulation quality in this scenario.

To find these designs, follow this step-by-step process:

1. On Product iQ, scroll down to the section entitled “IQ PLUS SEARCH TOOLS” and click on “Building Materials, Systems and Installation Codes,” then click on “Fire Rated Roofs, Walls, Floors, Beams and Columns.”
2. In the menus on the left, select or type the following:
   • Keyword – Netting
   • Fire-Rated Design Details Assembly Type – select Roof-Ceiling
   • Protection Type – select Gypsum Board
   • Additional Filter – select Steel Structure or Wood Structure appropriately
3. After entering the above, click “Search” to the right of Keyword. To view a preview of the drawing for each design, click the dropdown “Display” and select “Images.” To view the design, click on the link that begins with “BXUV.” Within each design, look for the insulation items that utilize wire mesh or netting.

Q: Are there UL fire resistance rated roof-ceiling designs that utilize spray foam plastic insulation to meet Grade I insulation quality standards?

A: Yes, spray foam is another type of insulation that readily fills areas around obstructions in the cavities, and it has the advantage of providing both air sealing and insulation.

To find these designs, follow this step-by-step process:

1. On Product iQ, scroll down to the section entitled “IQ PLUS SEARCH TOOLS” and click on “Building Materials, Systems and Installation Codes,” then click on “Fire Rated Roofs, Walls, Floors, Beams and Columns.”
2. In the menus on the left, select or type the following:
   • Keyword – Spray Foam Insulation
   • Fire-Rated Design Details Assembly Type – select Roof-Ceiling
   • Protection Type – select Gypsum Board
   • Additional Filter – select Wood Structure
3. After entering the above, click “Search” to the right of Keyword. To view a preview of the drawing for each design, click the dropdown “Display” and select “Images.” To view the design, click on the link that begins with “BXUV.” Within each design, look for the items entitled “Foamed Plastic.”

Q: Some UL assemblies resulting from the searches above include alternatives with the caveat that “the finished rating when this insulation is used has not been determined.” What does this mean?

A: The finish rating is an optional, supplemental metric that is separate from the hourly rating of the assembly. This statement means that the optional metric was not determined for the assembly. The building code only requires an hourly fire resistance-rating for the assembly. There are no code requirement related to the finish rating.

References: www.ul.com/AEC

You may also want to visit our Architectural, Engineering and Construction (AEC) Resources webpage for helpful information and guidance. This page includes guidance for using UL Product iQ and helpful FAQs about UL passive fire protection/fire resistance-rated designs and assemblies.