Safety Glass Rules for Shower Doors, Tub Enclosures and Bathroom Windows

Glass near a tub or shower is one of the places the building code treats as a hazardous location, because people slip in bathrooms and fall against what is in front of them. Ordinary annealed glass breaks into long, sharp shards; safety glazing either breaks into small pieces or holds together. This page explains where Washington requires safety glazing in a bathroom, how to tell whether glass qualifies, and what an inspector looks for, as of October 2026.

Which code applies

Washington has no amendment to the safety glazing section of the International Residential Code; WAC 51-51-0308 is "Reserved". So the model 2021 IRC section R308 applies as written. In Vancouver it is enforced through the city's building permit and inspections. The 2024 codes are scheduled to take effect on 3 May 2027; until then the 2021 text applies.

The tub and shower rule (R308.4.5)

The core rule reads: "Glazing in walls, enclosures or fences containing or adjacent to hot tubs, spas, whirlpools, saunas, steam rooms, bathtubs, showers and indoor or outdoor swimming pools where the bottom exposed edge of the glazing is less than 60 inches (1524 mm) measured vertically above any standing or walking surface shall be considered to be a hazardous location. This shall apply to single glazing and each pane in multiple glazing."

The exception: glazing more than 60 inches, measured horizontally, from the water's edge of a bathtub, hot tub, spa or whirlpool, or from the edge of a shower, sauna or steam room.

So the test has two parts. Is the glass in a wall or enclosure containing or next to the tub or shower? If yes, is its bottom edge under 60 inches above a standing or walking surface, and within 60 inches horizontally of the water's edge? If both, it must be safety glazing.

Other bathroom glass

What qualifies: the test standard

Safety glazing in Washington must pass impact testing. For most hazardous locations the code allows either the federal standard, CPSC 16 CFR 1201, or ANSI Z97.1. Bathrooms are an exception: glazing in doors and enclosures for hot tubs, whirlpools, saunas, steam rooms, bathtubs and showers must be tested to CPSC 16 CFR 1201, and Table R308.3.1(1) requires Category II for doors and enclosures covered by R308.4.5 (R308.3.1). The federal standard itself lists "Bathtub doors and enclosures" and "Shower doors and enclosures" among the products it covers.

Tempered glass is the common choice for shower doors and panels. The CPSC definition explains why it is ordered to size: tempered glass "cannot be cut, drilled, ground, or polished after treatment without fracture. When fractured at any point, if highly tempered, the entire piece breaks into small particles."

The mark the inspector looks for

Under R308.1, each pane in a hazardous location needs a manufacturer's designation that names who applied it, the type of glass and the safety glazing standard it meets. The mark must be "visible in the final installation" and "acid etched, sandblasted, ceramic-fired, laser etched, embossed, or be of a type that once applied cannot be removed without being destroyed." A label is permitted in lieu of the designation in some cases. The exceptions are narrow: non-tempered glass with a certificate or affidavit the building official approves, and tempered spandrel glass.

In practice, that small etched bug in the corner of the shower door is the inspector's proof. Do not let anyone grind it off or hide it behind a hinge or clip. Glass without a visible mark may have to be replaced to pass final.

Replacing glass in an existing bathroom

Washington's existing building rules say replacement glazing in hazardous locations must comply with R308 (R4502.5.2). An old shower door made of plain or wired glass cannot be replaced like for like; the new glass must be safety glazing with the required mark.

Shower door rules from the plumbing code

The plumbing code adds two dimensional rules that shape the glass design. "Thresholds shall be of sufficient width to accommodate a minimum 22 inch (559 mm) door. Shower doors shall open so as to maintain not less than a 22 inch (559 mm) unobstructed opening for egress." (UPC 408.5). The Washington plumbing code also sets the minimum shower size (900 square inches with a 30 inch circle). We found no Washington rule requiring hinged shower doors to swing outward; that rule is in the IRC plumbing chapter, which Washington does not use. Door swing is still a practical design question. See bathroom plumbing code.

When the glass goes in

Shower glass is measured after tile is finished, because tempered glass cannot be trimmed on site. That puts glass near the end of the schedule. Ask when the final building inspection will happen relative to glass installation, so the inspector can see the mark. The full sequence is on bathroom remodel inspections.

Who confirms

In Vancouver, the City of Vancouver building inspector checks safety glazing at final (Permit Center, 360-487-7833). In unincorporated Clark County, Clark County Community Development (564.397.4078). JDI Construction includes glass in the bathroom design and orders it once tile is set. See our Vancouver shower remodeling page.