Frameless Shower Installation
Critical accuracy. The most important aspect
of installing a frameless enclosure is getting the measurement
for the opening correct. You can be the best installer in the
world, but if the initial measurements aren't right, the unit
won't work. Kathy takes about two hours to produce an on-site
drawing, referring to a precise angle finder, a 4-foot level, a
plumb bob, and a square to record all dimensions, angles, and
transitions, and all plumb-and-level conditions. The basic
drawing is usually nothing fancier than a shop sketch for our
own use, although, occasionally, a client will want a more
elaborate, finished perspective drawing as a visual aid.
Accuracy is critical; any error will make for a very
unpleasant, perhaps impossible, installation later on. If the
wall is out of plumb, the glass must be fabricated accordingly.
Metal U-channels or clamps (Figure 3) hold the stationary
panels at the wall, so we allow for the metal thickness and
make a small deduction for clearance and adjustment. The
fabricator cuts the glass to our exact dimensions, but
edge-polishing usually knocks off another 1/16 inch, so we
might get a touch more play than indicated.
3. Wall-mount hinges and clamps or a metal
U-channel secure the glass to the wall, ceiling, and
floor. Deductions must be made from the overall
dimensions to accommodate hardware clearances (inset).
A glass corner clamp requires 3/4-inch-diameter
mounting holes in the adjacent panels. Glass corners
may be mitered, butted, or overlapped.
Tempered glass. The glass
in a frameless enclosure can be either 3/8-inch- or
1/2-inch-thick tempered panels. Tempered glass is nothing more
than common float glass that's been raised close to the melting
point — around 1,400°F — then quickly cooled by
quenching, which alters its molecular composition.
Ordinary plate glass, when broken, produces heavy, sharp,
potentially lethal shards. Tempered glass, on the other hand,
is seven to ten times stronger than plate glass, and very
difficult to break — in fact, you can drive a pickup
truck on a panel without breaking it (we've done it).
Peculiarly, in spite of its strength, the corners and edges
are very touchy. If you so much as nick the corner of a piece
of tempered glass, it could explode, but only into thousands of
small, lightweight granules that are unlikely to cause injury.
This is why building codes require tempered glass in all shower
enclosures, among other locations. It's also why we're
extremely careful not to allow any metal or tile to come in
contact with the edge of the glass.
Hinge decisions. There are a few different
ways to hinge a glass door. The size and weight of the door
determines some of the options. For example, 3/8-inch glass
weighs 5 pounds per square foot, so if the plan specifies a
32-inch-wide by 80-inch-high door, the weight would be
approximately 88.9 pounds. The maximum weight allowable for a
door using two Geneva hinges is 80 pounds, so we would need to
add a third hinge or adjust the door dimensions.
If we are working with a header and the door is not
wall-mounted, we use top and bottom pivot hinges. Both hinge
types have a detent device that aligns the door in the closed
Data forms. With all of
the final measurements established, we transfer the data for
each panel onto preprinted template forms that represent the
basic panel shapes and show all dimensions, holes, hinge
cut-outs, and miters. Our glass manufacturer, Solar Seal (55
Bristol Dr., So. Easton, MA 02375; 508/238-0112; ), which
provides us with high-quality product and fabrication —
important if you want your final product to be perfect —
works from the information we provide on the template drawings.
All of the cutting, shaping, and polishing is done before the
glass is tempered. After tempering, no modifications are
possible. Delivery time for the finished glass panels normally
takes three to six weeks.
We order all of our header and channel extrusions in stock
lengths, and cut them to size on the job site. The extrusions
are available in all kinds of finishes, including solid nickel,
brass, stainless steel, and even gold plate. Most of these are
easily cut by a power miter saw equipped with a good quality
triple-chip-grind carbide-tooth blade.
The first installation step is to establish a layout line on
the sill, walls, and buttress wall. A 2-inch-wide strip of
masking tape, applied first, provides a legible base for
marking that's easy to remove later (Figure 4). We transfer our
glass dimensions and any bisecting points to the tape from our
worksheet, and double-check all of the angles.
4. Masking tape provides a legible base for
marking the layout line, locating transitions,
hardware, and termination points, as well as quick line
removal. Clear plastic setting blocks are positioned
over the countersunk screw heads in the U-channel to
protect the vulnerable edge of the tempered glass panel
from contact with the metal and tiles.
Next, we cut and fasten the U-channels or clamps. To make
sure that the screw heads don't project and contact the edge of
the glass, we countersink the holes in the channel. A bead of
silicone on the underside of the U-channel seals and helps to
bond it to the tile surface. We install plastic wall anchors in
the tile to capture the screws, and use a razor blade to slice
the anchor flange off flush with the surface to eliminate any
gap behind the channel.Likewise, a quick touch with the
countersink bit cuts away the burr from the backside of the
screw holes in the channel.