Storefront glass: cleaning, inspection & when to replace

Quick answer: Storefront glass can last for decades with proper cleaning and routine inspection. On insulated glass units (IGUs), the edge seal is the part that wears out, and the inner cavity fogs once it fails. The two failures that end a piece of storefront glass early are impact damage (chips that grow into cracks) and seal failure on IGUs. Catch both early and you'll get the full life out of the glass.

This guide walks through everything a business owner or property manager needs to keep storefront glass looking right and lasting longer: the cleaning routine, what to inspect monthly, the common failures and what to do about them, when something repairable becomes a replacement, and when it's time to call us in.

What kind of glass is in your storefront

Before you can care for it, it helps to know what's actually in the frame. Three glass configurations turn up in commercial storefronts:

• Tempered single-pane. A single pane of tempered safety glass set into aluminum framing. It is strong, and if it ever breaks, it breaks into small pieces rather than large shards.
• Laminated. Two layers of glass bonded with a clear PVB interlayer. Used in high-traffic doorways, vestibules and anywhere a security or safety upgrade is wanted. If it breaks, the glass stays held together by the interlayer rather than falling out of the frame.
• Insulated glass units (IGUs). Two panes of glass separated by a sealed spacer with dry air or argon between them. Used in climate-controlled retail and modern commercial buildings. They bring an energy benefit, but the seal eventually fails and the unit fogs.

A storefront can mix all three, and the storefront door glass can differ from the fixed panels beside it: tempered or laminated in the entry doors, laminated in a vestibule, IGUs in the larger fixed display panels. If you're not sure what you have, look for an etched stamp in a lower corner of the panel; where there is one, it can tell you the type.

Daily & weekly cleaning

Storefront glass is the first thing customers see. The cleaning routine doesn't need to be complicated, but it should be consistent.

• Use pH-neutral cleaner. A diluted dish-soap solution or any commercial pH-neutral glass cleaner is ideal. Strongly acidic or alkaline cleaners can degrade tints and Low-E coatings over time.
• Microfiber and a squeegee, not paper towels. Paper leaves lint behind and can scratch glass over the course of years. A microfiber cloth picks up smears; a quality squeegee finishes streak-free in seconds.
• Top to bottom. Gravity is on your side: drips run down across glass you haven't cleaned yet.
• Avoid: ammonia-based cleaners on tinted or coated glass. Window cleaners with ammonia (the blue stuff) can damage tints and Low-E coatings over time, which is the easiest way to ruin an expensive IGU. If you have any tinted or insulated glass, switch the whole front to a pH-neutral cleaner; it's simpler than trying to track which panel is which.
• Avoid: abrasive pads and razor blades. Steel wool, scouring pads and razor blades on coated glass will scratch the coating permanently. If you must scrape a sticker, use a brand-new plastic blade and plenty of soapy water.
• Avoid: harsh degreasers near the aluminum frame. Strong solvents can dull the anodized or painted finish on the frame. A pH-neutral wash and a wipe-dry is all the frame needs.

A weekly cleaning is a sensible baseline. High-traffic doors, food businesses and ground-floor restaurants may need a daily wipe at the door pulls and lower panels, where hands and shoes leave marks.

Monthly inspection

Once a month, walk the storefront and look closely. A few minutes of looking can catch a problem while it is still small.

• Seals and gaskets. Run a finger along the perimeter of each panel. If the rubber gasket has shrunk back from the corners or feels dry and brittle, water and air are getting past it. Replace gaskets before they let water reach the IGU seal or the frame interior.
• Corners and edges. Look for small chips, "spider crack" patterns, or any star-shaped impact mark, especially at the bottom corners, where a key, a stroller wheel or a sign post can clip the glass. These start small and grow.
• Aluminum frame. Check for white powdery oxidation (look closely at older anodized frames near the threshold), loose screws, or any visible separation between the frame and the building. Loose frames let water in.
• The seal line on IGUs. If you see a faint dark band creeping in from the edges, or condensation inside the panel that doesn't wipe off, the seal has failed. Schedule an IGU replacement.
• Door operation. Watch for a door that has started to drag, close inconsistently or stop latching. Have the hardware it hangs on and its closer checked on a commercial door repair visit before the door starts torquing the glass it's mounted to.

Common storefront glass problems & fixes

Hazy or cloudy IGU

The cavity between the two panes of an insulated unit has gone milky or fogged. Cause: The edge seal has failed and moist outside air is now sitting between the panes. Fix: Replace the IGU. There is no way to dry out the cavity from the outside, because the seal is bonded to both panes and the spacer.

Small chip near an edge

A nick, ding or tiny crater near the perimeter of a panel. Cause: Impact from a key, a piece of equipment or a sign. Fix: Don't ignore it. Glass under thermal stress (sun heating one half while the other half is in shade) can turn an edge chip into a propagating crack. Ask whether a chip can be stabilized or the panel must be replaced, and have it looked at early. If the chip is anywhere near a mounting screw, the panel should be replaced.

Foggy condensation

Moisture inside an IGU that comes and goes with temperature swings. Cause: Same as hazy: a failed seal. Fix: Replace the IGU. The seal failure is what's letting the moisture cycle in and out.

Large crack

A crack longer than about two inches, or a crack that's reached an edge. Cause: Impact, thermal stress on a pre-existing chip, building movement, or rarely a manufacturing defect surfacing. Fix: Replace the panel. A large crack in storefront glass is a security issue (someone can complete the break with a fist) and a safety issue (tempered glass can shatter without warning once compromised). When the panel can't be replaced on the first visit, the opening is boarded up first and the replacement glass is fabricated to the opening.

Scratches

Surface scratches from a razor blade, a ladder edge, or abrasive cleaning. Cause: Maintenance damage. Fix: Ask whether light scratches on uncoated glass can be polished out or the panel must be replaced. Anything on a coated panel (Low-E, mirrored, tinted) cannot be polished without damaging the coating; the panel should be replaced if the scratch is in a customer sightline.

When to repair vs. replace

The rule of thumb is shorter than most people expect.

• Worth asking about: Small surface chips (penny-sized or smaller) more than a few inches from any edge or mounting screw. Ask whether one can be stabilized or the panel must be replaced.
• Replace: Any crack longer than about 2 inches. Any chip near a screw or hardware mounting point. Any IGU haze, fog or condensation between panes. Any spider-crack impact pattern. Any panel that's been hit hard enough to leave a visible mark even if it looks "fine", because tempered glass can fail later from latent damage.

If you're not sure, call us. We'll come look and tell you straight: if it's repairable we'll say so, and if it isn't we'll explain why.

Storm and impact damage

North Jersey storefronts deal with a real storm season: winter ice storms with high wind that throws debris, summer thunderstorms with the occasional hail event, and the leftover wind from coastal nor'easters and tropical systems pushing inland from the shore. Two things can take out commercial glass:

• Wind-driven debris. A branch, a sign, even a trash-can lid hitting an entry panel at speed will chip or crack tempered glass. Once it's chipped, the failure clock starts.
• Thermal shock. Heavy snow piled against a south-facing panel that then gets bright winter sun creates a big temperature differential across the glass. Any pre-existing edge chip becomes a stress concentrator and can crack through.

For a storm-damaged storefront, the opening is boarded up first to keep the business secure, then the replacement glass is measured and fabricated to the opening. What your policy covers is a question for your insurance agent.

Code & safety reminders

A few specifics worth knowing for any NJ storefront:

• Safety glass in and around doors. The National Glass Association's guidance for doors, side lites and entrances reads: "Fully tempered or laminated glass that meets ANSI or CPSC specifications is required." The federal safety standard for glazing in doors, as that rule defines them, is 16 CFR part 1201, and your town's construction official decides what a given opening needs.
• High-traffic and security applications can call for laminated. Vestibule doors, schools, after-hours-visible storefronts in higher-crime corridors all benefit from laminated glass, which holds together when broken.
• Glass walls and accessibility. What an accessible entrance needs is set out in the 2010 ADA Standards for Accessible Design, and the business's architect is the right person to apply them to a glass storefront or a full-height glass wall.
• Replacement should match the original spec. If a panel was originally tempered, the replacement must be tempered. Laminated for laminated. The original glazing was specified by the building's permit drawings for a reason.

When to call AGM

If you see any of the following, give us a call.

• A chip, crack or impact mark on any storefront panel
• Haze, fog or visible condensation inside an IGU
• A door that's binding, dragging or no longer closing flush
• Visible damage to gaskets, seals or the aluminum frame
• Storm or vehicle impact damage: the opening is secured first if needed, then the replacement glass is fabricated to the opening

We service commercial storefronts across Bergen County and North Jersey from our Lodi shop. See our commercial glass services page for the full scope, or jump straight to the contact form below for an estimate.