Know the Code: Glass Railing

Guard (a.k.a. guardrail)
A safety barrier such as a railing along open edges like decks, balconies, landings, and stair sides, that prevents falls.

Handrail
The graspable rail you hold while going up and down stairs. It has its own height and usability rules.

One piece can do both
The top of a guard can also serve as the handrail on stairs if it meets certain handrail rules (see below).

One‑ and two‑family homes
Most homes follow the International Residential Code (IRC).

Commercial buildings
Many multifamily projects and commercial buildings follow the International Building Code (IBC).

Local jurisdictions
State and local areas can amend either model (for example, requiring 42″ guards), so always check your local adoption and amendments before you finalize a design. For example, here is California’s Guardrail Code

For Reference: “Horizontal Railing Code” follows the same base guardrail requirements

Where guards are required
If there’s an open edge and the drop is over 30 inches anywhere within 36 inches (3 feet) of that edge, then you need a guard.

Residential guard height
Your guard must be at least 36 inches tall on level surfaces. On stairs, a guard is typically required when there are 4 or more risers, though some areas may require 42 inches — check your local code.

Top rail vs. handrail
The top of a guard may double as the handrail if it meets handrail rules.

Note: Local jurisdictions may require taller guards (e.g., 42 inches). When in doubt, design to 42 inches to satisfy the strictest common requirement, or verify with your inspector.

Height
The height of the handrail needs to be between 34 and 38 inches measured vertically from the line connecting the stair nosings (imagine a line that grazes the front edge of each tread — that’s the nosing line).

Continuity
Handrails must be continuous for the full flight, without gaps.

Returns
The ends of the handrail need to return to a post, guard, wall, or safety terminal to prevent snags.

When required
On stairways with 4 or more risers.

Your guard (guardrail) must block certain sphere sizes through any opening:

Railing infill
The space between posts (such as cables, rods, or panels) must block a 4-inch diameter sphere.

Stair guard infill
The space between posts on a stair guard (like a railing) must block a 4 3/8-inch sphere.

Stair triangle
The triangular gap formed by the tread, riser, and bottom element must block a 6-inch sphere.

With glass infill
Continuous glass panels typically satisfy opening limits. Pay attention to bottom gaps above floors, treads, or base shoes so the 4″ and 6″ rules are met.

Guards and handrails must withstand specified forces without failing (per IRC/IBC):

Top rail/guard/handrail
Should withstand 200 pounds of force in any direction at the top.

Infill
Should withstand 50 pounds of force spread over a 12 inch × 12 inch area.

Engineer’s perspective
Load compliance is about the system as installed rather than individual components. Always install per Viewrail instructions and use the specified fasteners/anchors for the surface you’re attaching the system to.

Glass Safety
Glass (a.k.a glazing) in guards or handrails It must pass one of two high-impact safety tests (CPSC 16 CFR 1201 Cat II or ANSI Z97.1 Class A). It is often required to be laminated safety glass — two layers of tempered or heat-strengthened glass bonded together.

Use laminated safety glass for most glass-guard applications — especially commercial, exterior, wind-zone, or frameless designs. Tempered glass may be used in certain interior, residential systems.

Top Rail
Normally, where glass panels provide structure and support for the railing and guard, you’ll need a continuous top rail so that the guard stays in place even if one panel breaks. There are exceptions to the rule, though you’ll need to work with an engineer and local inspector to ensure it stays code-compliant.

Hazardous locations
Because people can fall or push against it, glass in guards counts as a hazardous location and must be safety glazing.

Viewrail Glass
We only provide code-compliant glass railing, and our engineers work with local homeowners and builders to ensure every custom project passes local inspection with flying colors. We offer both tempered and laminated glass and test our glass well beyond minimum standards. Plus, we install custom, continuous top rails and have multiple options for glass railings with no top rail.

When it comes to panel sizing, every system is different and requires it’s own unique makeup to be code-compliant.

For each Viewrail glass system (Base Rail, Talon, Standoff Pin), there’s an ICC-ES evaluation report. Think of it as the official rulebook that tells you exactly what combinations are code-compliant: glass makeup, whether a top rail is required, how wide/tall each panel can be, how far apart clamps/anchors go, and what wind loads the system is rated for.

How panel size is decided:
Each report sets the limits based on:

• The system (e.g., Base Rail vs Standoff Pins)

• Guard height (a taller guard usually reduces max panel width)

• Glass makeup (thickness, tempered/heat-strengthened plies, and interlayer type)

• Top rail (having one can allow wider panels)

• Location and loads (interior vs exterior, design wind speed/pressure)

• Panel position (center panels can often be wider than end panels)

Typical rule of thumb:
As general rule, if you’re working with our Base Rail and it’s 42 inches tall, it’s typical to use middle panels up to 54 inches wide and end panels up to 48 inches wide. If you go with with a shorter height, stronger glass or a top rail, you may be able to use wider panels. In an exterior, high-wind, or no top rail situation, you may have to use shorter widths. Check the specific ICC-ES report to be sure.

Best practice
When you apply for a permit (or send shop drawings), include the exact Viewrail ICC-ES report for your system and show that you’re matching it line-by-line.

Pool barriers
In many places, a 48-inch minimum height is required for a pool guard. Exact rules for gates, latches, and clearances vary so check your local code.

Exterior glass
For typical homes, ½-inch tempered glass is common. For coastal, hurricane, or high-wind areas, plan on laminated glass as it’s increasingly required outside and resists wind pressure better. For exterior projects, SGP (SentryGlas Plus) glass is recommended, they hold up to UV and moisture and are even rated for hurricane-force winds.

Rule of thumb: ½-inch tempered for standard residential, 9/16-inch laminated for extreme wind or commercial exposure.

Outdoor hardware and finishes
Near the coast (within 5 miles), heavy UV, or acid rain zones, use 2205 stainless or aluminum with a fluoropolymer finish for better corrosion resistance.

Drainage and debris
Because glass can act like a solid wind/leaf screen, pick systems that leave a gap under the panels where you need drainage. In debris-prone areas, avoid fully enclosed base-rail channels. Popular pool-fence supports include Surface-Mounted Talons, Barrier Glass Posts, or Surface-Mounted Posts.

Mounting
Outdoor safety depends on the strength of the mounting structure. Depending on the deck/substrate, you may need through-bolts rather than lags.