How To Secure Rooftop Smoke Vents

Rooftop Smoke Vent Skylights

Installing rooftop smoke vents is a great way to reduce the dangers of a fire in a building.

However, one of the biggest concerns of safety professionals is to ensure that the solution to one hazard doesn’t create a new, unaccounted-for hazard. 

Any time we cut a hole in a walking surface or a roof, we need to keep in mind that it can put future workers in danger. These workers can vary from maintenance personnel to first responders, such as firefighters.

Rooftop smoke vents are no exception.

Most fire-related deaths occur due to the inhalation of toxic gases or smoke. Roof vents help to remove these hazards, as well as heat, from a building during a fire. Without a doubt, these devices can be, and have been, life savers.

Consult these NFPA standards to determine the specifics of how they need to function.
Consult your local building codes to determine if a vent is required.

If left unprotected, however, these same life-saving devices could prove life-threatening by introducing a fall hazard. So how do we protect these vents so that workers and emergency responders are safe when having to work around them?

What Does OSHA Say About Rooftop Vents?

Safety Inspector

By OSHA’s definition, rooftop vents are holes either because they could be open at times, leaving an actual hole, or because the covers aren’t manufactured to support the weight of a human. 

According to 29 CFR 1910 Subpart D, a hole is a “gap or open space in a floor, roof, horizontal walking-working surface, or similar surface that is at least 2 inches (5 cm) in its least dimension.” Two inches isn’t that much, so it’s important to evaluate your walking and working surfaces. But let’s stick to roof vents. 

Some are designed as hatches which would have a suitable cover when closed. There are any number of times those hatches could be open, such as during maintenance activity or if the vent is being used as roof access. This exposes workers to a potential fall. While open, they also pose a hazard to any firefighters on the roof trying to fight a blaze.

Other smoke and heat vents are designed as skylights. Regardless of whether these skylights are activated through a fusible link, manually, electronically, or designed to shrink and drop out at certain temperatures, OSHA will consider them a hole unless their dome is designed to withstand at least two times the maximum intended load.

OSHA says in 29 CFR 1910.28(b)(3) that holes more than 4 feet above a lower level need fall protection. This can be in the form of a cover, guardrail, or personal fall protection system.

The question is, how will these work for a smoke vent on a roof? Let’s go over the options.

Safety Covers for Rooftop Smoke Vents

Skylight screens on roof vents

Smoke vents often are installed as rooftop skylights. Skylight screens are the most common cover and protection for a skylight. They will provide the quickest, most cost-effective, and space-saving fall protection for skylights.


Skylight screens are not good solutions for smoke vents. These covers interfere with the vent’s operation. In the event of an emergency, the installed screen will most likely be too heavy for the vent to properly open. This is the classic example where one solution creates another problem.

It is very important to check with the manufacturer of the smoke vent with the details of the proposed cover to find out if it can work.

Personal Fall Protection Systems for Smoke Vents

Rooftop Lifeline

Is a personal fall protection system, like a lifeline, a viable option for smoke vent safety? 

Well, yes and no. 

They certainly would work as protection for maintenance personnel because they’re going to have enough time to ensure they’re properly secured if there’s enough fall clearance. However, firefighters certainly won't have the luxury of time nor are they likely to be wearing fall safety harnesses.

So why install a system that only takes care of part of the problem? 

Also, every PFPS requires a qualified person and training for everyone using the system. Then there’s the human factor. Employees need to follow procedures, do it properly, and do it 100% of the time.

Another major part of a personal fall arrest system is the rescue plan. How feasible would it be to expect to be able to perform a rescue of a suspended firefighter in the middle of a fire?

While a personal fall protection system is compliant with OSHA if you meet all of the various requirements (check out our lifeline guide), we don’t recommend it for smoke vents.

Safety Guardrails for Smoke Vents

Rooftop Smoke Vent Guardrail

As we’ve outlined above, screens and personal fall protection systems aren’t the best options for smoke vents. Especially if these vents come in the form of a roof hatch. The best option is the last remaining one from OSHA…guardrail.

Guardrails don’t require any training to use and won’t interfere with the operation of the smoke vent if designed appropriately. There are a lot of options available as well. You can use mounted hatch railings for a fire vent or non-penetrating guardrails for skylight smoke vents.

Just ensure the guardrails are spaced far enough away that the domes or vent doors do not collide with the railing during operation.

You can also use a guardrail to cordon off a whole section of the roof to prevent access to a large number of vents. However, this doesn’t help you if emergency workers need to access that side of the roof.

When skylight screens are not feasible for a skylight smoke vent, then guardrails can be designed to allow enough space for vent operation.

Guardrails are the best option for smoke vent safety. Railings are easy to install and flexible enough in design to allow plenty of room for hatch operation. They are also much more visible to workers and emergency responders.

The Next Steps

As you can see, just because OSHA allows a safety solution, doesn’t mean it’s right for your situation. Take the time to evaluate your roof smoke vents and determine the best way to protect your workers and the emergency personnel that need to access the roof.

We recommend using guardrails to protect your rooftop smoke vents. This will offer protection for anyone who accesses the roof without having to train them.

Contact an expert to help you determine the best way to protect your rooftop smoke vents.

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