Roof hatches are a common building component that are used to access the roof for maintenance purposes, such as air treatment systems, air conditioning units and other mechanical systems.
While common, they are not explicitly addressed in by the International Building Code for fire protection. Most code experts agree roof hatches are addressed in Section 712.1.15, which uses the term “skylights and other penetrations.”
Another code, Section 711, which addresses Floor and Roof Assemblies, could be cited by some code enforcement experts and come to a different conclusion. That code states “penetrations or other openings are permitted according to Section 712, provided that the fire-resistance rating is maintained.” Roof hatches, however, are not fire-rated products.
The code ambiguity deserves a deeper dive, as the lack of clarity means different code experts may have different interpretations of whether roof hatches are required to be fire rated for a particular project.
Roof hatches provide access to a building’s roof, typically via a fixed interior ladder. They are manufactured in standard sizes and custom sizes can also be fabricated. They are installed at hospitals, offices, industrial buildings, retail facilities, and any commercial building that requires roof top access.
Fire protection experts primarily refer to Section 712.1.15 concerning Skylights when determining if they meet code requirements. This section states that “unprotected skylights and other penetrations through a fire-resistance-rated roof deck or slab are permitted provided that the structural integrity of the fire-resistance rated roof assembly is maintained.”
This means that, in most cases, roof hatches are not required to be fire-rated, even in fire-rated roofs as they are not a structural component of the roof assembly.
However, a rarer scenario arises when Section 705.8.6 of the IBC, addressing Vertical Exposure, comes into play. It stipulates that if a building is within 15 feet of another building or has a stepped roof, non-rated roof hatches (or skylights) are not permitted, as they would affect the fire separation requirements. In these cases, fire-rated access doors are required as defined in Section 7220.127.116.11.
The IBC Commentary of Section of 712.1.15 elaborates on this issue, emphasizing that: “Fire-resistance-rated roof construction is not intended to create a barrier to contain the fire within the building, except for Exception 1 of Section 705.8.6 and the exception to Section 706.6.1. Non fire-resistance rated penetrations are, therefore, permitted to be installed in fire-resistance-rated roof assemblies, provided that the structural integrity of the roof assembly is not reduced and provisions of Section 705.8.6 for protection of vertical exposure do not apply.”
Section 711 of the IBC addresses Floor and Roof Assemblies and requires horizontal assemblies to be continuous with vertical openings, as regulated by Section 712.
It further states that penetrations or openings in the assembly are permitted according to Section 712, provided that the fire-resistance rating is maintained. This provision could lead some code enforcement officials to question whether non-rated roof hatch installations in fire-resistant horizontal assemblies are permitted. However, as noted above, Section 712.1.15 allows non-fire rated hatches in rated assemblies and is therefore the code that is most frequently applied.
Manufacturers of roof hatches maintain that their products are not integral parts of roof assemblies and, therefore, do not impact a roof’s fire-resistance rating or the structural integrity of roof.
IBC Section 1501, states that a Roof Assembly is “A system designed to provide weather protection and resistance to design loads. The system consists of a roof covering and roof deck or a single component serving as both the roof covering and the roof deck. A roof assembly includes the roof deck, vapor retarder, substrate or thermal barrier, insulation, vapor retarder and roof covering.”
The inclusion of roof hatches within the definition of a roof assembly is not stipulated. Therefore, it is appropriate to adhere to Section 712.1.15, which permits skylights and other penetrations through a fire-resistance-rated roof deck or slab to be unprotected. This allowance is applicable assuming that Section 705.8.6 which concerns vertical exposure for buildings on the same lot does not apply.
European products that are marketed as fire-rated and available in the U.S. market add another layer of complexity to the situation.
These products undergo testing according to European standards, specifically EN1634-4 and UL-EU, which are not referenced in the IBC or applicable to U.S. fire protection standards.
Despite these European roof hatches incorporating non-combustible mineral wool insulation and achieving fire ratings of up to 4 hours, the IBC generally does not mandate fire ratings for roof hatches, even within fire-rated assemblies. This situation raises questions about the applicability and relevance of such products in most U.S. construction scenarios.
Over the past few years, rooftop bars have become a popular trend among restaurants. While not suitable for every environment, they are nonetheless an alternative that many people enjoy. The ability to enjoy fresh air and take in city surroundings from a different perspective delights many people.
Safe egress, however, is a frequent concern and the increasing trend of rooftops being utilized as additional occupiable spaces is prompting a potential shift in building codes to prioritize enhanced safety measures. Consequently, in the future rooftops may be subjected to code requirements like those applied to indoor floors. This evolution could lead to a need for fire protection ratings on roof hatches.
One solution for such an application could be fire-rated access doors. These specialized doors are designed to preserve the fire rating of a floor/ceiling assembly. They incorporate intumescent coatings that resist the passage of heat, gases, and flames, thereby ensuring a higher level of safety. In rare instances, code officials may mandate this elevated level of safety for occupiable rooftops to align with the changing landscape of rooftop utilization.
MULTIPLE SIZES, MATERIALS
BILCO manufactures roof hatches designed for safe and convenient access to roof areas. These hatches are available in various sizes and feature engineered lift assistance, making them suitable for accessing equipment and servicing building needs.
Roof hatches are available in steel, aluminum, and stainless-steel construction and can be supplied in an energy efficient, thermally broken design that features R-20+ insulation and a special gasket for wind resistance.
While most fire protection officials subscribe to the theory that fire protection ratings for roof hatches are not mandatory, it is crucial to acknowledge the potential for variations in interpretation by code officials.
Local code amendments or ordinances could be in place that would supersede IBC codes. Such variations can arise with any code provision. Therefore, it remains best practice for architects and construction managers to proactively engage in collaborative discussions with code officials to ensure adherence to the building codes before commencing construction. This proactive approach will help in preempting any discrepancies and will ensure alignment with the local code interpretations and requirements.
It would be beneficial for a subsection to be developed in the IBC to specifically address roof hatches. Until such a change is made, treating roof hatches and skylights similarly, in alignment with the prevailing expert consensus, appears to be a prudent approach during pre-construction planning.
About the Author:
Thomas Renner writes on building, construction, and other trade industry topics for publications throughout the United States.
Modern Contractor Solutions, December 2023
Did you enjoy this article?
Subscribe to the FREE Digital Edition of Modern Contractor Solutions magazine.