Use Sprinklers at Window Instead of 1-Hr Glazing?

1/15/2024

I have a project in the Miami area where there are some exterior glass panels that need to be 1-hour fire rated.

I specified the glass to be fire rated type, but it prices are coming back too high. The contractor is looking into an alternative of providing fire sprinkler protection on the inside face of the glass.

Is this a feasible idea?

The wall that the glass is part of requires the rating due to its being within 10' of some adjacent exterior glass.

Thanks in advance.

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12 Comments

Pete H

1/15/2024 06:36:09 am

Based on this handy dandy Meyer Fire write up, there's definitely some things that can be done, especially with Tyco WS sprinklers:

https://www.meyerfire.com/blog/windows-sprinklers-fire-ratings-part-i

Check it out, read the pdf. It's worth it.

Dan Wilder

1/15/2024 07:05:35 am

If this is acting as an exposure type system with sprinklers on the exterior to protect your building from the adjacent building (possibly unsprinklered or already has the rated glass), you're looking at a deluge system. If it's just a separation between two sprinklered buildings, you can likely get the AHJ to approve interior closed WS on your building only. If it's the same building with some large architectural inset(s), interior sprinklers should be acceptable as well.

All 3 MFG's have options (no particular order):

Reliable - https://www.reliablesprinkler.com/featured-solutions/window-protection-sprinklers/

Tyco - https://www.tyco-fire.com/products-and-solutions/sprinklers-nozzles-and-accessories/special-application/cws-ws_fis/models-cws-and-ws-sprinklers

Viking - https://www.vikinggroupinc.com/products/window-sprinklers/vk960-vk962-pendent-vertical-sidewall-and-horizontal-sidewall-specific

1/15/2024 08:08:11 am

Exactly what Dan said. Make sure the glazing & mullions conform to the WS requirements if you go that route.. there's quite a few. Check the data sheets.

Jim Stever

1/15/2024 08:08:08 am

Agree with above comments. However, what happens when the fire sprinkler system is down. I would still use rated glazing

Glenn Berger

1/15/2024 08:54:40 am

Dan laid out the thought process exactly correct. Depending on the occupancies and the hazards that are present will advise which is the right way to go.

Matthew Signes

1/15/2024 08:55:04 am

Victaulic also has a Specific Application Window Sprinkler solution.

https://www.victaulic.com/products/firelock-series-fl-sa-ws-sprinklers/

Dan Wilder

1/15/2024 04:11:07 pm

Good call....haven't tried them!

Jesse

1/15/2024 10:09:52 am

Yep, we've encountered this on numerous projects due to the price of rated glass. There are numerous window protection sprinklers on the market. Just make sure the sprinkler you choose is listed for such use.

Casey Milhorn

1/15/2024 12:55:56 pm

Agree with Dan. Make sure that you follow the listing of the head and/or if using SS heads (when allowed by applicable codes, AHJ, etc) follow IBC/IFC and NFPA 13 standard.

Typically the sprinklers cannot be used for operable doors or windows, load bearing walls, or when horizontal mullions are present that protrude out from glazing. Butt type is okay. Also, there is a maximum vertical distance for protection.

Keep in mind that the WS heads from Tyco (and others I believe) must have the deflector down at the top of the glazing. I believe Reliable has a concealed version that works pretty well if coordinated with an architectural feature like a soffit.

The fire rated glazing is expensive, but I've had several projects where the architect wished they would have went that route after they find out they can't use the WS heads because it's outside the listing and/or the install ends up being ugly and costly to conceal the piping.

Ivan Humberson

1/16/2024 11:19:32 am

You will definitely want to check with the AHJ to work toward a solution. If the jurisdiction enforces NFPA standards, then, to my knowledge, there is no NFPA compliant alternative to a 1-hour assembly that allows sprinkler-protected glazed openings.

Todd E Wyatt

1/22/2024 03:49:20 pm

“Water curtains” are permitted to be substituted for fire-resistance rated (FRR) opening protectives in buildings protected throughout by an automated sprinkler system (ASPS) by the scoping Code (e.g. IBC-2021 705.8.2) if approved by the AHJ (e.g. Building Official).

Opening Protectives (OP) are (typically) required based on the Fire Separation Distance (FSD) between the Exterior Walls (EW) and adjacent building(s) and/or the property line(s).

ASPS are not permitted to substitute for the minimum FRR of building elements, components or assemblies UNLESS an “alternative design” is submitted the AHJ and they approve it (per IBC-2021 104.11). Other than the exception for OPs per 705.8.2, the 1-Hr Fire Barrier (1FB) protection of atrium (window) walls can be downgraded to a 1-Hr Smoke Barrier (1SB) if IBC-2021 404.6 (3) Exceptions are met. ASPS providers have tried to use this atrium ASPS exception as a substitution for other FRR assemblies. Only the AHJ can approve of these “alternative designs.”

Todd E Wyatt

1/22/2024 03:49:52 pm

REFERENCES
IBC-2021
Chapter 7 Fire and Smoke Protection Features
Section 705 Exterior Walls
705.8 Openings
Openings in exterior walls shall comply with Sections 705.8.1 through 705.8.6.
TABLE 705.8 MAXIMUM AREA OF EXTERIOR WALL OPENINGS BASED ON FIRE SEPARATION DISTANCE AND DEGREE OF OPENING PROTECTION
705.8.2 Protected Openings
Where openings are required to be protected, opening protectives shall comply with Section 716.
Exception: Opening protectives are not required where the building is equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 and the exterior openings are protected by a WATER CURTAIN using automatic sprinklers approved for that use.

Section 703 Fire-Resistance Ratings and Fire Tests
703.2 Fire Resistance
The fire-resistance rating of building elements, components or assemblies shall be determined in accordance with Section 703.2.1 or 703.2.2 without the use of automatic sprinklers or any other fire suppression system being incorporated, or in accordance with Section 703.2.3.
703.2.1 Tested Assemblies
703.2.2 Analytical Methods
703.2.3 Approved Alternate Method
The fire resistance of building elements, components or assemblies not complying with Section 703.2.1 or 703.2.2 shall be permitted to be established by an alternative protection method in accordance with Section 104.11.

Chapter 1 Scope and Administration
Section 104 Duties and Powers of Building Official
104.11 Alternative Materials, Design and Methods of Construction and Equipment
The provisions of this code are not intended to prevent the installation of any material or to prohibit any design or method of construction not specifically prescribed by this code, provided that any such alternative has been approved. An alternative material, design or method of construction shall be approved where the building official finds that the proposed alternative meets all of the following:
1. The alternative material, design or method of construction is satisfactory and complies with the intent of the provisions of this code,
2. The material, method or work offered is, for the purpose intended, not less than the equivalent of that prescribed in this code as it pertains to the following:
1. Quality.
2. Strength.
3. Effectiveness.
4. Fire resistance.
5. Durability.
6. Safety.
Where the alternative material, design or method of construction is not approved, the building official shall respond in writing, stating the reasons why the alternative was not approved.

Chapter 4 Special Detailed Requirements Based on Occupancy and Use
Section 404 Atriums
404.6 Enclosure of Atriums
Atrium spaces shall be separated from adjacent spaces by a 1-hour fire barrier constructed in accordance with Section 707 or a horizontal assembly constructed in accordance with Section 711, or both.
Exceptions:
1. A fire barrier is not required where a glass wall forming a smoke partition is provided. The glass wall shall comply with all of the following:
a. Automatic sprinklers are provided along both sides of the separation wall and doors, or on the room side only if there is not a walkway on the atrium side. The sprinklers shall be located between 4 inches and 12 inches (102 mm and 305 mm) away from the glass and at intervals along the glass not greater than 6 feet (1829 mm). The sprinkler system shall be designed so that the entire surface of the glass is wet upon activation of the sprinkler system without obstruction;
b. The glass wall shall be installed in a gasketed frame in a manner that the framing system deflects without breaking (loading) the glass before the sprinkler system operates; and
c. Where glass doors are provided in the glass wall, they shall be either self-closing or automatic-closing.

Use Sprinklers at Window Instead of 1-Hr Glazing?

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