Shower Glass Guide: Thickness, Low-Iron Glass & Coatings

Tempered safety glass is required

Safety glazing: glass in shower and tub enclosures is a "hazardous location" under the Florida Building Code, Residential, so it must be safety glazing, which for shower doors almost always means tempered glass (2023 Florida Building Code, Residential (8th ed.), Section R308.4.5 Glazing and wet surfaces; Florida Building Commission, Analysis of Changes, 8th Edition (2023) FBC-Residential). Federal rules in 16 CFR Part 1201, Safety Standard for Architectural Glazing Materials (eCFR) cover safety glazing used in shower and bathtub doors and enclosures. Look for the permanent tempered-glass mark (the "bug") in a corner of each panel.

Tempered glass breaks into small, dull pieces rather than long shards (HomeGuide, "How Much Does It Cost to Install a Shower Door? (2026)"). It can't be cut or drilled after tempering, so every panel is made to measure.

3/8" vs 1/2"

• 3/8": the standard for most frameless doors. Lighter on hinges and easier to open. HomeGuide lists standard 3/8" clear at about $12–$50 per sq ft (HomeGuide, "How Much Does It Cost to Install a Shower Door? (2026)").
• 1/2": heavier and more solid-feeling, often used for fixed panels. HomeGuide: about $15–$58 per sq ft, and notes that fixed frameless panels are typically 1/2" while the door is 3/8" for easier opening (HomeGuide, "How Much Does It Cost to Install a Shower Door? (2026)"). Angi notes such panels can weigh 80 lbs or more (Angi, "Pros and Cons of Frameless Shower Doors").
• Framed doors use thinner glass because the frame supports it (Angi, "Pros and Cons of Frameless Shower Doors").

Low-iron (ultra-clear) glass

Standard clear glass has a slight green tint that shows on the edges and in thick panels. Low-iron glass (sold as Ultra Clear, Starphire and similar) is more transparent. HomeGuide puts the upgrade at about +$6–$15 per sq ft (HomeGuide, "How Much Does It Cost to Install a Shower Door? (2026)").

Privacy glass

Frosted (acid-etched) glass adds privacy and hides water spots, at about +$2–$11 per sq ft. Textured or rain glass is about +$2–$12, and gray or bronze tint about +$4–$12 (HomeGuide, "How Much Does It Cost to Install a Shower Door? (2026)").

Protective coatings

Factory or applied coatings (EnduroShield, ShowerGuard, Diamon-Fusion and others) help water bead off and resist spotting and staining, about +$4–$20 per sq ft (HomeGuide, "How Much Does It Cost to Install a Shower Door? (2026)"). Angi says coatings can add about 30% to the door cost (Angi, "Pros and Cons of Frameless Shower Doors"). That can be worth it if your water is hard.

Hardware near the coast

In beachside towns, salt air is hard on metal. Ask installers which finishes they recommend and what the warranty covers.