Read Storm Ratings with Confidence

Storm ratings on impact windows show how well a window is built to resist wind-borne debris in a hurricane. The rating is the tested performance of the whole window, not a sales label. Knowing how to read it helps you plan your project and ask the right questions early.

Short answer: what a storm rating tells you

A storm rating is the tested performance level of an impact window. It shows what the window was proven to withstand in a lab.

Florida law limits how impact protection can be sold. Under Fla. Stat. § 553.842, a product may not be advertised, sold, or marketed as hurricane, windstorm, or impact protection from wind-borne debris unless it is approved under that section or § 553.8425, and anyone who does so without approval is subject to the Florida Deceptive and Unfair Trade Practices Act. Products used for local approval, including windows, must show compliance with the structural windload requirements of the Florida Building Code through one of the listed methods under Fla. Stat. § 553.8425.

So the approval is the proof behind the rating. This page explains the three items you’ll see on paperwork: the test results, the pressure value, and the approval number. It then covers how the rating affects your opening and your schedule.

How the tests work: missile impact and pressure cycling

Two lab tests drive most storm ratings: a large-missile impact test and a cyclic pressure test.

In the missile impact test, a projectile is fired at the window. The window must stay intact after the hit. The Impact-rated glass resource covers windows that use impact-rated glass, fire-resistant glass, or protective coverings.

The cyclic pressure test loads the window with pressure that rises and falls over and over. This copies the push and pull of wind gusts on a wall. A window passes only if it stays intact and within its stated limits after the full sequence.

The rating covers the whole assembly. The frame, glass, anchors, and sealant are tested together. Florida’s evaluation rules require a complete product description and installation instructions for windows, including attachment. Fla. Admin. Code R. 61G20-3.005 sets out those requirements.

Reading the rating on your product paperwork

The design pressure is the load the window is rated to resist on the wall where it sits. A higher number means a higher performance level. The report should also list the conditions and limits of use.

Approvals can be revised. A revised approval keeps the same Florida product approval number and adds a revision number, such as R1 or R2. Fla. Admin. Code R. 61G20-3.012 describes this process.

Your quote should match the approval documents for the product you order. A rating applies only within the limits the report lists, such as size and configuration. If the numbers don’t match, ask about it before you sign.

Why the rating has to match your opening and local code

One window rating does not fit every wall.

Miami-Dade County’s product testing process is described on its county product testing guidance page.

A permit reviewer compares the approval documents with the product that gets installed.

Planning the timeline: opening count, product, and the permit lag

Your timeline depends on how many openings you have and which product you choose. More openings mean more measurements, more paperwork, and a longer installation.

Projects may move through these phases: survey and measurement, product selection, order, permit submittal, permit approval, installation, and inspection. A different product can change the order and approval steps too.

Permit review runs on the local building department’s schedule, and that queue often sets the start date. Permit requirements for exterior impact window replacement can vary by city, and our team can discuss the steps that apply to your project. The Opa-locka’s municipal permit page is specific to that city and does not set rules for other South Florida areas.

You can keep things moving by having documents, photos, and access ready. Name the person who will let the crew in at each stage.

What to prepare before the free first consultation

Gather the property address, a list of every opening, any existing product labels or approval numbers, and photos of each opening. Bring questions too. Ask which rating applies to each opening, what the permit package includes, and how the schedule gets set.

The first consultation is free, confidential, and carries no obligation to continue.

Common questions