Rules for Roof Hatches Lack Clarity

Building codes are developed, written, and analyzed to remove ambiguity and provide precise details about which materials are appropriate — and those that are not.

In some cases, however, there is a lack of clarity regarding codes. One of those instances centers on roof hatches. While roof hatches are included in almost all commercial projects, these specialty access products are not specifically addressed 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.” Some enforcement officers, however, could cite another code, Section 711, which addresses Floor and Roof Assemblies. That code does not specifically address roof hatches, but 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 lack of clarity has confused some architects and builders. While some code enforcement officers might have differing opinions, a consensus of experts believe roof hatches do not require a fire rating in the U.S. market.

Common Building Component

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.

They are installed at hospitals, offices, industrial buildings, retail facilities and almost any commercial building that requires roof access. From the standalone pharmacy down the street to the fast-food restaurant in the strip mall, roof hatches play an important role in providing access to rooftop equipment. In many cases for larger commercial properties, there are multiple roof hatches.

While a common building product, the IBC does not include language that refers to roof hatches. The closest language is Section 712.1.15. “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.”

The key phrases are “unprotected,” “other penetrations” and “roof assembly.” Roof hatches are not considered a structural component of the roof assembly, as they do not impact a roof’s fire-resistance rating or the structural integrity of the roof.

There is, however, a unique application that would require a roof hatch to be rated, as outlined in section 705.8.6, which addresses vertical exposure. This section 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. While it would seem that this application would call for a fire rated roof hatch, it is actually dictating the use of a fire rated access door.

Alternate Perspective

Confusion develops, however, from Section 711 of the IBC, which addresses Floor and Roof Assemblies. While this section does not directly mention roof hatches, it requires horizontal assemblies to be continuous with vertical openings, as regulated by Section 712.

This section says penetrations or openings in the assembly in the roof are permitted, as regulated by Section 712, provided that the fire-resistance rating is maintained. This provision could lead some code enforcement officials to question whether a non-rated roof hatch in fire-rated assemblies is permitted. However, Section 712.1.15 permits the non-rated product.

Adding to the confusion is whether roof hatches are integral parts of a roof assembly. 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.” Skylights and roof hatches are not addressed.

With that language, Section 712.1.15 is the most frequently cited code in permitting non-rated roof hatches to be installed. Section 705.8.6, which concerns vertical exposure for buildings on the same lot, could require the installation of a fire-rated access product, but not a roof hatch.

The European Model

Further complicating the decision-making process for building materials experts is a European roof hatch that is marketed as fire rated.

These hatches are tested to European standards, specifically EN1634-4 and EL-EU, which are not referenced in the IBC or applicable to U.S. fire protection standards.

The hatches incorporate non-combustible mineral wool insulation and do not specifically address heat transfer with an intumescent or any other fireproof coating. Since the IBC does not mandate fire ratings for roof hatches and does not have a required test standard, the European product is not applicable for the U.S. market and its fire protection code requirements.

New Trends

New trends in using rooftops as occupiable spaces could lead to the development of fire-rated roof hatches at some point in the future.

Rooftop bars have become popular over the past few years. “Something about escaping the demands of everyday life high above the hustle and bustle below appeals to all of us,’’ Mandy and Kelvin Slater wrote in an FSR article in 2019. Slater Hospitality designed, built and operates a rooftop bar at Ponce City Market in Atlanta that has been in business since 2016.

Consequently, rooftops with such spaces may be subject to code requirements such as those that apply to indoor floors. This evolution could lead to fire protection ratings on roof hatches, particularly if they are used as primary access to rooftop areas by the general public.

Ingress and egress on rooftop bars or other occupiable spaces are primary considerations for builders. While the spaces offer delightful social opportunities, there are significant hazards that must be carefully considered.

Safe and Convenient Access

Hatches are available in various sizes and feature engineered lift assistance, making them suitable for safely and conveniently accessing equipment and servicing building needs. Roof hatches are available in steel, aluminum, and stainless-steel construction.

One of the more popular building trends is the installation of a thermally broken roof hatch. The design features R-20-plus insulation and a special gasket for wind resistance. The hatch minimizes heat transfer between interior and exterior metal surfaces, resists harmful condensation and provides superior energy efficiency.

Do the Homework

While most fire protection experts believe non-rated roof hatches meet code requirements, it is crucial to acknowledge the potential for variations in interpretation by code officials. There could be local amendments or ordinances that could mandate fire-rated roof hatches for a project. Such variations can arise with any code provision.

Architects and construction managers should engage in collaborative discussions with code officials to ensure adherence to building codes before commencing construction. A proactive approach will help to preempt any discrepancies and ensure alignment with local code interpretations and requirements.

About the author: Steve Weyel is the Director of Sales and Marketing for The BILCO Company. This article was developed in consultation with The Hickman Group of Plantation, Florida, which provides a wide range of consulting services to companies, trade associations and organizations in building, mechanical, energy, green/sustainability and fire codes and standards. For more information, visit bilco.com and thehickmangroup.com.