Shower glass & frameless doors
A frameless shower looks simple, but the glass is doing structural work and sitting in one of the most demanding environments in the home: constant moisture, hard water, and a real risk of impact. That is why shower glass is almost always thick tempered safety glass, and why a few specification details make the difference between a panel that stays crystal-clear and one that fogs, stains, or fails inspection.
It has to be safety glass
Glass in and around a bathing area is a "hazardous location" in the building code (IRC R308.4 and IBC Section 2406 in the US), which means it must be safety glazing. In practice that almost always means tempered glass, which breaks into small, relatively blunt cubes instead of long shards. Safety glazing for showers must meet CPSC 16 CFR 1201 Category II or ANSI Z97.1 Class A, and every panel should carry a permanent etched stamp in a corner identifying the fabricator and standard. If a shower panel has no visible safety stamp, treat that as a red flag.
Thickness: framed vs. frameless
Framed enclosures use a metal frame for rigidity, so the glass can be thinner. Frameless enclosures rely on the glass itself plus a few hinges and clamps, so the glass has to be thick and stiff.
| Style | Typical glass | Notes |
|---|---|---|
| Framed | 1/4 in (6 mm) | Metal frame on all edges adds stiffness and hides edges; lowest cost |
| Semi-frameless | 1/4 to 5/16 in (6 to 8 mm) | Frame on some edges only |
| Frameless (standard) | 3/8 in (10 mm) | The most common heavy-glass choice; good stiffness and feel |
| Frameless (tall / large) | 1/2 in (12 mm) | For tall doors and wide panels, to limit flex and "wobble" |
Low-iron glass for true clarity
Standard float glass has a faint green tint from its iron content, and that tint becomes very noticeable in thick glass viewed edge-on, exactly the situation in a 10 to 12 mm shower panel. For a clean, colorless look, many frameless showers specify low-iron glass (sold as Starphire® by Vitro, Optiwhite™ by Pilkington/NSG, and similar names by other makers). It costs more but removes the green cast, which is most worth it on clear glass next to white or light-colored tile. See tinted & low-iron glass for the difference.
Edgework
Because a frameless panel has no frame covering its edges, those edges are both visible and exposed to handling, so they are finished. A flat-polished (or pencil-polished) edge is standard on exposed edges: it looks finished, is comfortable to touch, and removes the micro-damage that could start a crack. Edges hidden inside a hinge or wall channel may only need to be seamed. Good edgework also matters structurally, since a clean edge is less likely to harbor the flaws that lead to breakage. See edge finishing for the finish levels.
Keeping it clear: easy-clean coatings
The enemy of shower glass is hard-water spotting: minerals left behind as water evaporates, which over time can etch into the glass surface permanently. An easy-clean (hydrophobic) coating makes water bead and sheet off, dramatically reducing spotting and cutting cleaning effort. These coatings can be factory-applied to the finished tempered glass or applied in the field, and they are one of the most common upgrades on a frameless shower. They are not permanent forever and can be reapplied, but they make day-to-day maintenance far easier.