If you're responsible for classroom safety at a school or university, you've likely heard about lockdown shades—window coverings designed to block visibility during emergency situations. The ALP Lockdown Shades for Classroom Window & Door Coverings for School Safety in Traditional Fabric represent one approach to this critical need. But before you order, understanding how to measure your windows correctly and pick the right size is genuinely important. Getting this wrong means the shade won't fit properly when you need it most.

Why Accurate Measurement Matters for Lockdown Window Coverings

The most common mistake people make when ordering blackout window shades for classroom safety is underestimating how much the shade needs to overlap the glass. Unlike decorative curtains, lockdown shades must completely block visibility from outside. Even small gaps around the edges can compromise safety and defeat the purpose of the covering.

The ALP Lockdown Shades come in nine standard sizes that fit windows commonly found in schools and universities, plus custom sizing options for unusual openings like sidelights and media centers. But this flexibility only works if you measure correctly from the start.

Understanding the Standard Size: ALP 10" x 30" and What It Means

When you see a blackout shade labeled with dimensions like 10 inches by 30 inches, these measurements refer to the actual fabric width and length. However, this is where many people get confused. The shade itself is smaller than the window opening it covers—it's designed to mount above the window and overlap the edges.

Before you choose your size, the instructions for ALP Lockdown Shades specify that you should add 3 inches to your glass width and 5 inches to your length. This overlap is not optional. It's what ensures complete blackout coverage and prevents anyone from seeing into the classroom during a lockdown situation. If your actual window glass measures 7 inches wide and 25 inches tall, you would order a shade designed to be 10 inches wide and 30 inches tall—that's where the arithmetic comes in.

How to Measure Your Classroom Windows Correctly

Start by measuring the glass opening itself—not the frame around it. Measure the width of the glass from edge to edge, then measure the height from top to bottom. Use a metal tape measure and take the measurement at least twice to confirm accuracy. Different windows in the same school can vary slightly, so measure each one individually.

Once you have those base measurements, add 3 inches to the width and 5 inches to the length. Write down this adjusted measurement. This is the shade size you're actually ordering. The ALP brand offers standard sizes in increments that match common classroom windows, so your adjusted measurement should correspond to one of their nine standard options. If it doesn't fall neatly into a standard size, or if your window is an unusual shape, that's when you'd consider a custom size from ALP.

Installation and Long-Term Care

The ALP Lockdown Shades use a hook-and-loop adhesive system for mounting, which means no drilling or tools are required. The shade attaches to the wall or frame around your window using strong adhesive strips. This makes installation relatively quick, though you'll want to ensure the surface is clean and dry before applying the strips.

For care, these shades are made from industrial-grade blackout polyester that meets NFPA 701 flame-retardant safety standards. You won't need to wash or replace them frequently under normal classroom conditions. However, the adhesive strips that hold them in place may eventually lose effectiveness, particularly in high-traffic areas with temperature fluctuations. Plan to inspect the strips every year or so and replace them if they've loosened.

The patented quick-release strap on each ALP Lockdown Shade allows it to drop instantly during an emergency, with tabs at the bottom to secure it without fumbling. This mechanism should be tested periodically as part of your school's lockdown drill procedures to ensure it operates smoothly when needed.

Choosing Between Standard and Custom Sizes

Standard sizes available for the ALP Lockdown Shades work well for most typical classroom windows found in schools built within the last several decades. If your school's windows fall within common dimensions, ordering a standard size is straightforward and often more cost-effective. Custom sizing from ALP becomes necessary for entranceways with sidelights, media center viewing windows, or older buildings with non-standard window dimensions.

Measure twice, calculate your overlap, and verify your chosen size against the available options before ordering. Accurate measurement at the beginning prevents delays and ensures your ALP Lockdown Shades for Classroom Window & Door Coverings perform their intended function when speed and visibility control matter most.

The product in this guide: ALP® Lockdown Shades for Classroom Window & Door Coverings for School Safety in Traditional Fabric. Patented Blackout Design for Lockdowns. Custom & Standard Sizes. Made in USA (Polyester, 10" x 30")