Roof vents have a long history in building design. For decades, they were standard practice in warehouses and large storage facilities. But as automatic fire sprinkler systems have become more advanced, a critical question has emerged: do roof vents actually help when sprinklers are present, or can they make things worse?

The answer is more complicated than many people expect. The 2025 edition of NFPA 13, Standard for the Installation of Sprinkler Systems, made a significant change to address this issue directly. The updated language is stronger and clearer than ever before: automatic roof vents are not required where sprinkler systems are in place, and if they are installed, they must meet specific criteria to avoid interfering with sprinkler performance.

This article explains what the codes require, why the change was made, and what fire protection professionals, facility managers, and Authorities Having Jurisdiction (AHJs) need to know when evaluating buildings that have both sprinkler systems and roof vents.

What Changed in NFPA 13 (2025 Edition)

The 2025 edition of NFPA 13 strengthened its language on roof vents and draft curtains in Section 20.9.5. The key change is found in Section 20.9.5.1, which now states plainly that automatic roof vents shall not be required in areas protected by automatic sprinkler systems.

This is a meaningful shift in tone. In the previous (2022) edition, the language allowed manually operated roof vents or automatic vents with a higher temperature rating than the sprinklers. The 2022 text was permissive. The 2025 text goes further by affirmatively stating that automatic vents are not required at all where sprinklers are installed.

The annex note in Section A.20.9.5.1 explains the reasoning: sprinkler protection criteria assume that roof vents and draft curtains are not being used, and their presence could be detrimental to sprinkler performance. The annex further cautions that if manual vents are provided, they should not be opened until the fire has been controlled or suppressed.

Section 20.9.5.2 addresses the scenario where automatic vents are installed anyway. In those cases, the automatic roof vents must have both a higher temperature rating and a higher Response Time Index (RTI) than the automatic sprinklers. The intent is clear: the sprinklers should activate first. Vents should not open before the sprinklers have had the opportunity to control the fire.

The change was driven by Fire Revision FR-1266, with the stated goal of reasonably limiting the detrimental impact of automatic roof vents on the performance of automatic sprinkler systems.

Why Automatic Vents Can Hurt Sprinkler Performance

To understand why this matters, it helps to understand how sprinklers work. Automatic sprinklers activate when the heat from a fire raises the temperature at the sprinkler location to the rated activation temperature. The goal is for sprinklers near the fire to open quickly and apply water before the fire grows.

Roof vents change the environment in ways that can interfere with that process. When a vent opens above or near a fire, it draws the hot gas plume upward and out of the building. That sounds beneficial, but it has an unintended consequence: it cools the air at the ceiling level, which delays or prevents nearby sprinklers from reaching their activation temperature.

Appendix C.6 of NFPA 13 documents this concern directly. Tests conducted as part of the standard’s development found that open venting caused 87.5 to 91 percent more sprinklers to operate than comparable tests without open venting. More activated sprinklers mean a larger demand on the water supply and a less efficient fire control operation.

Research cited in NFPA 204 adds further nuance. One study found that when a vent was located directly over the fire, it reduced the number of sprinkler activations, because the heat was drawn straight up and out. But when the fire was located between vents, the disrupted airflow increased the number of sprinklers that activated. The inconsistency alone is a reason for caution. The designer cannot always predict where a fire will start.

There is also a documented risk with Early Suppression Fast Response (ESFR) sprinklers. These systems are specifically designed to suppress fires in high-challenge storage environments before the fire grows large. They rely on rapid activation. NFPA 204 notes concern that early vent operation could delay sprinkler activation and undermine the suppression the ESFR system was designed to provide. For this reason, the interaction of vents and ESFR sprinklers have not been fully validated by research, and the guidance documents treat it with heightened caution.

If Venting Is Required: The Right Way to Do It

There are situations where local codes or occupancy requirements mandate smoke and heat removal in a sprinklered building. In those cases, NFPA 13, NFPA 1, and NFPA 204 all point toward the same conclusion: if venting is required, it should be designed to avoid opening before the sprinklers have controlled the fire.

Three principles guide best practice when venting must coexist with a sprinkler system:

1. Manual operation is preferred. Manual vents give firefighters control over when venting occurs. They will not accidentally draw the heat plume away from sprinklers before the fire is controlled. NFPA 13 and NFPA 204 both acknowledge that manual exhaust is an appropriate post-fire tool for smoke removal.
2. If automatic vents are used, they must be a standard response. Fast-response or quick-response vents are particularly dangerous in sprinklered buildings. A vent that activates before the sprinklers is a vent that may be working against the suppression system. Standard response fusible elements ensure a slower, more deliberate activation.

 

3. Temperature ratings must be significantly higher than the sprinklers. NFPA 13 requires that any automatic vents have a higher temperature rating than the sprinklers. NFPA 1 specifies a minimum of 360 degrees Fahrenheit (182 degrees Celsius) for buildings with ESFR sprinklers. NFPA 204 recommends a minimum activation temperature of 180 degrees Celsius (356 degrees Fahrenheit) for buildings using 74-degree Celsius rated ESFR sprinklers. The gap in temperature ratings ensures the sprinklers activate and begin suppression well before any vent opens.

Draft curtains raise additional concerns. Multiple research programs have found that draft curtains can direct the spread of fire rather than contain it. Where combustible storage is located near a draft curtain, the curtain can funnel the fire toward adjacent areas. NFPA 204 recommends that draft curtains be located in aisles and separated from combustible contents whenever possible.

NFPA 13 and the IFC: Similar Goals, Different Paths

It is worth noting that NFPA 13 and the International Fire Code (IFC) approach this issue from different starting points, and the differences have practical implications for building owners and AHJs.

NFPA 13 takes a broad position: automatic roof vents are not required wherever a sprinkler system is present. The standard does not restrict this to specific occupancies or storage configurations. It applies across the board. This reflects the body of research behind the standard, which shows that the design basis for sprinkler protection assumes vents are not present.

The IFC takes a more occupancy-specific approach. Under the 2026 IFC, smoke and heat removal requirements for high-piled storage are governed by Table 3206.2, which specifies when smoke and heat removal systems are required based on the type of commodity, storage height, and building size. Where that table calls for venting, the IFC generally requires it, unless the building is protected by ESFR sprinklers. When ESFR sprinklers are the protection method, the IFC allows the omission of automatic smoke and heat venting systems, recognizing the suppression capability of ESFR technology and the documented risk that vents pose to ESFR performance.

In summary, NFPA 13 recommends omitting automatic venting any time a sprinkler system is present. The IFC requires venting in certain high-piled storage occupancies per Table 3206.2, but permits omission specifically when ESFR sprinklers are used. The two frameworks align on the core concern about ESFR systems but differ on how broadly the principle applies.

This difference matters when a jurisdiction adopts the IFC but local ordinances also reference NFPA 13. In those situations, practitioners should apply the more protective standard and document the basis for their design decisions.

What This Means for Your Facility

For facility owners and managers, the practical takeaway is straightforward. If your building has an automatic sprinkler system and also has automatic roof vents, those vents deserve a careful look. Ask these questions:

Are the vents automatic or manual?

Automatic vents that can open before a fire is controlled are the primary concern. Manual vents that require firefighter or operator action are a much lower risk.

What is the temperature rating of the vents?

If automatic vents are present, are they rated significantly higher than the sprinklers? Do they meet the minimum thresholds in NFPA 13 and NFPA 1?

What type of sprinklers are installed?

If ESFR sprinklers are installed, automatic vents are especially concerning. Both the IFC and NFPA 204 recognize the heightened risk of combining ESFR protection with automatic venting.

Which code applies?

Determine whether your jurisdiction follows NFPA 13, the IFC, or both. Understand where the requirements differ and apply the most protective standard.

For fire protection engineers and AHJs, the 2025 NFPA 13 change is a signal to revisit existing designs and permit reviews with fresh eyes. Buildings that were designed under previous editions may have automatic venting that no longer aligns with current best practices. This is not necessarily a compliance violation for those older buildings, but it is a conversation worth having with owners and insurers.

Conclusion

The 2025 edition of NFPA 13 reflects decades of fire research and real-world experience with sprinkler performance. The core message is clear: when automatic sprinklers are present, automatic roof vents are not required, and they can be detrimental to the suppression process if not carefully designed.

If venting is required, the path forward is well defined. Vents should be manually operated whenever possible. If automatic vents are used, they must be standard response with temperature ratings significantly higher than the automatic sprinklers. For ESFR-protected buildings, the bar is even higher, and both the IFC and NFPA guidance point toward eliminating automatic venting entirely.

The goal of every fire protection system is to put water on the fire as quickly as possible. Roof vents should never slow that process down. The updated NFPA 13 language is a step toward making sure they do not.