I n t h e K n o w

Considerations for Glass Railings

by Nick St. Denis

rchitects continue to trend toward cleaner

views, fewer sightlines and smooth edges when

specifying glass.

but safety concerns led the IBC to adopt laminat-

ed glass and top rail requirements in 2015.

This is certainly true with glass railings, though What it Says

the newest International Building Code (IBC) has

thrown a wrench into the mix.

The 2015 IBC requires glass used in a handrail,

guardrail or guard shall be laminated and con-

structed of fully tempered or heat-strengthened

glass. It also says any lite of glass used in the sys-

tem shouldn’t be thinner than one-quarter inch,

and glass balustrades shall not be installed with-

out an attached handrail or guard.

There are two key exceptions in the code.

First, single fully-tempered glass is permitted

where there is no walking surface beneath the sys-

tem, or when the walking surface is fully protected

from the risk of falling glass.

Second, a top rail is not required where the

balustrade is laminated glass consisting of two or

more glass lites of equal thickness and same glass

type when approved by the building official.

Attention to Edges

Exceptions that allow for laminated glass with-

out a top rail pose a challenge for the glass indus-

try. Glass fabricators are now faced with improving

the edge quality in the laminated glass they pro-

duce, as two pieces of glass sandwiched together

with an interlayer looks much different than the

smooth edge of a single lite of monolithic glass.

Chatfield notes that it’s very difficult to get two

lites of glass to line up perfectly, but that the glass

industry has done a good job making improvements.

The 2015

The 2015 IBC, which went into effect two

years ago, largely requires that glass railings use

laminated glass and include a top rail in many

applications.

With that, the glass industry, and manufac-

turers of these railings systems, regularly work to

educate the design community on how this code

affects their ability to achieve their desired look.

International Building

Code has specific

requirements regard-

ing laminated glass

and the inclusion of

a top rail in certain

applications.

“

Fabricators are now improving their manufac-

Less Metal, More Glass

turing processes when it comes to edge quality,”

adds Brian Clifford, director of architectural rail-

ings and metals for C.R. Laurence. “Double arris

polished edges were the norm in the past. Now we

are seeing external arris edges and seamed internal

edges, which typically require post polishing.”

“

Architects often look to take out any visual

obstructions when implementing a glass bal-

ustrade system in their designs,” says Andrew

Chatfield, director of architectural railing systems

at Wagner Companies.

Chatfield says that while a post-and-rail system

is more reliant on metal and a base shoe system

allows for a greater area of glass, “the last thing an

architect wants to do is put a big piece of metal

across the glass.”

All About Location

Whether or not the new IBC Codes apply

depends on jurisdiction. The International Code

Council has a chart on its website, www.iccsafe.org,

noting which codes apply to which state. As of June,

only 18 states have adopted the 2015 IBC. AGG

In years past, designers have often leaned

toward using monolithic glass without a top rail,

www.glassguides.com

Architects’ Guide to Glass & Metal