How to Tell If Windows Are Impact-Resistant: 4 Checks

Check 1

Find the permanent label on the frame or sash

Open the window and inspect the head, jambs, sill, sash edges, and meeting rail. Use a flashlight and your phone camera; small labels are often easier to read in a zoomed photo. Do not remove glazing beads, pry trim, or force a sash to expose a label.

Record every piece of identifying information you can find:

• manufacturer name and product series;
• model, order, or unit number;
• manufacturing date or plant code;
• an AAMA/FGIA certification label and any impact-specific tab;
• missile level, tested size, pressure-cycle information, or the word “impact”;
• a Florida Product Approval number, often shown as an FL number, or a Miami-Dade Notice of Acceptance number.

Check 2

Inspect the corners for etched glass markings

Look closely at all four corners of every pane. A permanent etch may be faint, so view it from both inside and outside and place a dark sheet of paper behind the mark if glare makes it hard to read.

Words such as “laminated” or “LAM” indicate laminated safety glass. Some insulated impact windows combine a laminated pane with another pane that is tempered or heat-strengthened. That is why one “tempered” mark does not necessarily rule out an impact-rated insulated unit.

However, markings such as ANSI Z97.1 or CPSC 16 CFR 1201 identify safety-glazing compliance. They do not, by themselves, show that the entire window passed hurricane debris-impact and pressure-cycle testing. Use the etched information to locate the manufacturer and glazing makeup, then confirm the exact window model.

Check 3

Look for a laminated glass interlayer

Impact-resistant glazing commonly uses two glass plies bonded to a resilient interlayer. If the glass edge is safely visible, you may see a thin line between the plies. In already-damaged laminated glass, fragments often remain bonded in a spiderweb pattern instead of falling out of the opening.

Treat the interlayer as a supporting clue. Laminated glass can be used for security, sound control, ultraviolet protection, or other safety applications. Hurricane-impact performance applies to the tested window assembly — not just to a piece of glass.

Check 4

Verify the model, approval, and installation record

This is the decisive step. Search the manufacturer’s current or archived technical documents using the series and model number. Match the window type, size, glazing option, frame, and impact designation — not merely the brand name. A product line may include both impact and non-impact configurations.

Also review documents that came with the home or project:

• window order sheets and paid invoices;
• permit files and final inspection records;
• product approval sheets and installation instructions;
• warranty documents showing the exact model and glazing package.

If the label lists a Florida approval or Miami-Dade NOA, verify that exact number in the official database. These records can identify the tested configuration and limitations. For a Louisiana or Mississippi project, local acceptance and required protection still depend on the authority having jurisdiction, the site, and the adopted code.

What does not prove a window is impact-resistant?

Several common clues are useful for understanding a window, but they are not proof of hurricane-impact performance.

Impact-rated, laminated, and tempered are not the same

An impact-rated window is a complete product system tested for debris impact and repeated pressure cycling. Laminated glass uses an interlayer that helps keep broken glass bonded, but laminated glass alone does not confirm the rating of the complete window. Tempered glass is heat-treated safety glass designed to break into smaller pieces; by itself, it is not hurricane-impact glass.

Impact-rated windows can crack when struck. Their purpose is to help keep the opening protected after impact and pressure cycling, not to remain cosmetically undamaged or become “storm-proof.” A cracked or damaged unit should be assessed and replaced as directed by the manufacturer.

Which standards should appear in the product record?

Common hurricane-impact records reference ASTM E1886 and ASTM E1996, or AAMA 506. The record may also state a large- or small-missile level, impact speed, tested unit size, and pressure-cycle result. The exact required rating and approved installation depend on the opening, building, exposure, local code, and permitting authority.

For Louisiana and Mississippi Gulf Coast homes, do not assume that one statewide rule applies to every parish, county, or municipality. Confirm the adopted code and project requirements with the local authority having jurisdiction before ordering or replacing windows.

What to do if you cannot confirm the rating

1. Photograph everything. Capture the full window, each label, every glass etch, the lock and hardware, and the exterior frame.
2. Collect the records. Ask the seller, previous contractor, manufacturer, permit office, or property manager for the original order information.
3. Do not advertise the window as impact-rated without proof. “Laminated,” “tempered,” and “storm window” are not interchangeable claims.
4. Get a professional evaluation. A window specialist can identify the series, document damage or installation concerns, and explain replacement or opening-protection options.

If your existing units are not confirmed as impact-rated, the next decision is usually between approved storm protection and a complete impact-window replacement. Compare the cost, deployment requirements, energy performance, maintenance, and protection of every opening — not only the glass.

Frequently asked questions