Protective and resistive assemblies, rated from 20 minutes to 2 hours
Fire-rated glazing lets a building keep daylight and visual connection in places where code requires a rated separation. Modern products are clear and available in large listed sizes — a long way from the wired glass most people picture.
The critical thing to understand before specifying anything: the rating belongs to the tested assembly, not to the glass. Glass, framing, hardware and installation method are listed and labelled together. A rated pane in an unrated frame is not a rated opening, and an inspector checking the label will fail it.
We supply and install rated assemblies, working from the architect's fire rating schedule. See SAFTI FIRST for the manufacturer we work with most in this category, and Optimum Window for fire-rated steel windows.
Fire-rated glazing splits into two categories that are not interchangeable. Confusing them is the most common and most expensive error in this field.
| Fire Protective | Fire Resistive | |
|---|---|---|
| Typical ratings | 20, 30, 45 minutes | 60, 90, 120 minutes |
| Blocks flame and smoke | Yes | Yes |
| Blocks radiant heat | No | Yes |
| Area limits apply | Yes | No |
| Can act as a wall | No | Yes |
| Tested to | NFPA 252 / 257, UL 10C / UL 9 | ASTM E119 / UL 263 |
Fire protective glazing blocks flame and smoke but not radiant heat. Standing beside it during a fire, you would feel the heat coming through. Because of that, codes limit the glazed area permitted and it cannot serve where a wall is required.
Fire resistive glazing, tested to the wall standard ASTM E119, blocks radiant heat as well. That is why it can function as a transparent wall with no area limitation.
The failure runs the same way every time: drawings call for a rated wall, someone supplies protective glazing because the rating number looks adequate and it costs less, and it fails inspection with the glass fabricated and the framing installed. We check which category the code actually requires before anything is ordered.
Lot line and property line openings. Where a building sits close to a boundary, glazed openings in that wall generally require rating. In the dense boroughs this is the most frequent trigger by some margin.
Stairs, corridors and exit passageways. Enclosures protecting the means of egress require rated construction, and any glazing in them must match. Modern designs increasingly want daylight in stairs, and fire-resistive glazing is what makes that possible.
Atria and floor openings. Rated separation is generally required around a penetrated floor, and rated floor systems exist for the horizontal condition.
Institutional, educational and transit buildings. Higher occupancy and more demanding egress requirements mean more rated separations — and these are exactly the buildings where transparency between spaces is wanted for supervision and wayfinding.
Requirements depend on construction type, occupancy, separation distance and the code edition in force. Confirm with your architect or code official; this page describes the product, not your project's obligations.
If your reference point is an older building, you expect wired glass in a small pane with an amber cast. Current products are clear, with high visible light transmission and listed sizes large enough that a rated separation can read as an ordinary glass wall.
That changes what is architecturally possible rather than just what complies. A rated stair can be glazed. A corridor separation can be transparent. Daylight and visual connection no longer have to be traded away for fire separation.
Framing follows the same logic — rated aluminium systems come in multiple profile depths with powder coat, anodised and other finish options, so a rated assembly can be detailed to sit alongside the non-rated glazing rather than standing out.
Tempered glass is not fire-rated. Tempered is a safety glass, addressing injury from breakage. It has no fire rating and fails quickly under fire conditions. A specification calling for safety glass has said nothing about fire.
Wired glass is largely restricted now. It carries a fire rating but performs poorly as a safety glass, and its use in hazardous locations has been substantially limited in the US for that reason.
Listed assemblies cannot be resized on site. Listings specify maximum tested dimensions. A rated unit cannot be cut down or reconfigured in the field, which makes accurate survey before fabrication more important here than on any other glazing.
Temperature-rise doors are a separate product. Doors into exit stairs may be required to limit how much the stair-side face heats up, since people press against them while evacuating. That restricts the permitted glazed area, and on some conditions rules out vision panels entirely. Establish it before a design commits to a glazed stair door.
Lead times are long. Submittals, approvals and fabrication all take time and none of them compress well. If rated glazing is in the specification, start early.
Send us the fire rating schedule, the opening sizes and locations, and whether any opening carries a security or impact requirement as well.
We will confirm whether the assembly as drawn is achievable within a tested listing, whether protective or resistive is required, what the realistic lead time looks like, and where a design change would save cost without affecting compliance.
This page will be expanded with fuller detail. In the meantime call 929-235-1233 or send us the drawings and we will answer directly.
This glass is stocked or ordered through our Staten Island shop and delivered across the five boroughs, Long Island, Northern New Jersey and the Jersey Shore — or collected by appointment. We install it ourselves in Brooklyn, Manhattan, Queens, the Bronx and Staten Island: the Oldcastle storefront glass at 3915 Flatlands Avenue and on Coney Island Avenue in Brooklyn, the Solarban argon units at 2518 Ocean Avenue, the laminated acoustic window at 1763 Amsterdam Avenue in Harlem, and the low-iron guards at Ocean Parkway. For supply without installation, see material supply and pick-up.
SAFTI FIRST Optimum Window Laminated Glass Tempered Glass Commercial Doors Glass Specifications Case study: 60-minute glass and wired glass VE
Fire-rated glass is glass tested in a listed frame to hold back flames and smoke for a stated time — 20, 45, 60, 90 or 120 minutes. There are two classes and they are not interchangeable: fire-protective glass (ceramics, wired glass, specialty tempered) stops flames and smoke but lets radiant heat through, and is limited to 45 minutes in most openings; fire-resistive glass (multi-layer laminates with intumescent interlayers) also blocks heat and is rated to 60, 90 and 120 minutes as a wall. Which one an opening needs is set by the code, not by preference.
| Rating | Class | Test standard | Typical products | Typical tested size limits* |
|---|---|---|---|---|
| 20 min | Fire-protective | NFPA 252/257, UL 10C/9 | Ceramic (FireLite), filmed or laminated ceramic, specialty tempered (SuperLite I-XL), wired glass | Large; often 100 sq in per door lite unless fire-resistive |
| 45 min | Fire-protective | NFPA 257 / UL 9 (openings), UL 10C (doors); hose stream required over 20 min in doors | Ceramic (FireLite, FireLite Plus, Pyran), SuperLite I-XL (no hose stream, AHJ approval) | Up to about 3,300 sq in in walls, 95″ max dimension; door lites 100 sq in in 60/90-min doors unless fire-resistive |
| 60 min | Fire-resistive (or protective ceramic in a 60-min wall opening) | ASTM E119 / UL 263 for resistive | SuperLite II-XL 60 (1-3/8″), Pilkington Pyrostop 60; ceramics allowed only in limited openings | SuperLite II-XL 60 up to about 4,950 sq in; FireLite in 60-min walls 3,325 sq in |
| 90 min | Fire-resistive | ASTM E119 / UL 263 | SuperLite II-XL 90 (1-1/2″), Pyrostop 90 | FireLite in 90-min walls 2,627 sq in, 56-1/2″ max; resistive laminates larger |
| 120 min | Fire-resistive | ASTM E119 / UL 263 | SuperLite II-XL 120 (1-3/4″, 16 lb/sq ft), SuperLite II-XLM 120 (1″, 12.3 lb/sq ft), Pyrostop 120 | SuperLite II-XL 120 up to 4,876 sq in; II-XLM 120 3,855 sq in (87-5/8″ square) |
*Manufacturer-published maximums for the glass in its own listed framing; the frame listing can reduce them. Verify against the current listing before specifying.
Fire-protective glass passes NFPA 252 or 257: it stays in the frame and keeps flames and smoke on one side for the rated time, and above 20 minutes it survives the hose stream — a fire hose played on the hot glass to prove it will not shatter when the sprinklers or the fire department arrive. It does not stop radiant heat, so the code limits it: 45 minutes in most openings, 100 square inches per lite in 60- and 90-minute doors, and it cannot be used where the code calls for a wall rather than an opening.
Fire-resistive glass passes ASTM E119, the wall test: the unexposed face stays below 250°F average rise for the rated time, so a person could stand next to it. That takes several lites laminated with intumescent interlayers that foam into an opaque insulating char in a fire — which is why 120-minute glass is 1 to 1-3/4 inches thick and weighs 12–16 lb per square foot. Because it is tested as a wall, it can be used without the size limits of protective glass, up to the tested lite size, in corridor walls, stair enclosures, exit passageways and property-line conditions. Our article on the 45, 60, 90 and 120-minute ratings goes through each in detail.
Stair and corridor doors in multifamily buildings (vision panels, usually 20 or 45 minutes in a rated door); lobby and corridor walls where an architect wants glass on a rated line (60 or 90-minute resistive); exit passageways and elevator lobbies (60 to 120); openings within the property-line setback where the exterior wall is rated; and school, hospital and lab partitions. Wired glass, the historic answer, no longer meets impact requirements in doors and is being replaced by filmed or laminated ceramics. Every fire-rated lite is installed in a listed frame with the glazing tape, stops and stop heights the listing specifies; the glass and frame are one assembly and one label.
We supply and install fire-rated glazing in listed steel and aluminium frames from the manufacturers named above, and we replace broken fire-rated lites in existing frames with the matching listed product. We do not substitute: a 45-minute ceramic where the drawing says 60-minute resistive is a code violation, and the label on the corner of the glass is checked by the inspector. Send the door or wall schedule and the rating, and we will confirm the product, the size limit and the frame.
Fire-protective glass (ceramics, wired, specialty tempered) stops flames and smoke but not radiant heat; it is tested to NFPA 252/257 and limited to 45 minutes in most openings. Fire-resistive glass (intumescent laminates) also blocks heat, is tested to ASTM E119 as a wall, and carries 60, 90 and 120-minute ratings.
Ceramic glass such as FireLite or Pyran, filmed or laminated versions where impact safety is required, or a specialty tempered product like SuperLite I-XL with the authority’s approval. Sizes up to about 3,300 square inches in walls.
Fire-resistive multilaminates: SAFTI FIRST SuperLite II-XL and II-XLM or Pilkington Pyrostop, 1 to 1-3/4 inches thick, tested to ASTM E119 in listed frames. Ceramics are allowed in 60- and 90-minute walls only within limited opening sizes.
It depends on the product and its listing: ceramics up to about 3,325 sq in at 60 minutes and 2,627 sq in at 90; fire-resistive laminates up to roughly 3,855–4,950 sq in at 60–120 minutes. Door vision panels in 60- and 90-minute doors are limited to 100 sq in unless fire-resistive glass is used.
After the furnace test the hot glass is hit with water from a fire hose; it must stay in the frame. It is required for all US ratings over 20 minutes in doors and over 45 minutes generally, and for every rating in Canada.
In doors, sidelites and other hazardous locations, yes: it must also meet CPSC 16 CFR 1201 impact ratings. Plain wired glass no longer qualifies; filmed and laminated ceramics and resistive laminates do.
Yes, with the matching listed product in the existing listed frame, glazed to the listing. The replacement has to carry the same rating and the same label.
Tell us about the opening and we will specify it for you.
