by Regina R. Johnson
Few people are better qualified to share their insights into the nuances and pitfalls of the frameless shower enclosure installation than Danny Donahue, a veteran in the area from its beginnings a decade ago. Donahue, a product specialist in the shower door technical services division of Los Angeles-based C.R. Laurence Co., Inc., drew upon his extensive experiences in the field for his seminar, Advanced Shower Door Installation Techniques, at Glass Expo Pacific NorthwestÔ 98 in August.
As an installer of frameless enclosures in Southern California for years before joining C.R. Laurence, Donahue noted that this design has become more affordable and consequently become a lucrative market in recent yearsone that the residential glazing contractor would do well to pursue.
An appreciation of the features that distinguish frameless enclosures from "integrated" enclosures is essential, according to Donahue. For one thing, the frameless shower can seldom be made completely "leak-proof," and the customer must be made aware of this fact. Another challenge of the design is that almost every installation is a little different.
During the design phase, Donahue advised providing the customer with all options in detail from the beginning, and allowing him or her to choose without influencing the decision. "Ive found that giving the customer more options as opposed to leading them in the direction that I want them to go is a way to gain their trust and close the sale," he said. Donahue suggested that a portfolio with photography of various installations can be helpful in demonstrating the possibilities to customers.
Above all other design considerations, safety is the most important, according to Donahue. It may be necessary to make this point with the customer who is firm in his or her desire for a design that may be unsafe. Remember that you, as the glazing expert are responsible for ensuring the safety of the enclosure. Donahue described the use of a waiver signed by the customer, freeing the installer from any legal liability in a potentially unsafe installation. However, he warned that not even this is an airtight defense.
Even more so than standard enclosure installations, good frameless installations rely upon proper measurements made as precisely as possible, according to Donahue. "Math is your friend," he advised, reminding seminar participants that of the many variables involved in these jobsover which most the installer has no controlmeasurements are the one thing he or she can use to an advantage.
A clear understanding of measuring terminology is a good start. The center-line is an often-misunderstood measurement, according to Donahue. "The center-line is the imaginary line that divides the glass thickness in half," he explained. Imaginary lines, by contrast, occur where a glass panel is aligned with or meets with "nothing." For example, there is an imaginary line where the frameless shower door meets with a fixed panel because the door doesnt actually meet flush with anything (i.e., hardware or a wall).
Donahue devoted a portion of the seminar discussing the calculation of angles, emphasizing once again, "Math is very important; it will set you apart." He reminded that determining the miter angle where two panels of glass meet is as easy as dividing the reciprocal angle by two. The reciprocal angle is found by subtracting the enclosure angle from 180 degrees.
For instance, for an angle measuring 155 degrees, subtract 155 from 180, and divide this number, 25, by two. The miter angle should be 12-1/2 degrees. Another example is a neo-angle, usually 135 degrees. By subtracting 135 from 180, and dividing this amount, 45, by two, you determine that the miter angle is 22-1/2 degrees.
A square cut door closing to a mitered fixed panel is even easier to determine, said Donahue. The reciprocal angle is the amount by which the return miter should be angled. Therefore, for a door and panel with an angle of 155 degrees, the return miter should be cut to 25 degrees.
Donahue also shared a few of the techniques hes picked up over the years. Several of these follow.
Glass sizing, Donahue emphasized, depends on sound mathematics in determining accurate clearances and deductions. The key is knowledge of your components and the various allowances they require. One helpful component in this process is the use of a construction calculator that adds and subtracts fractions.
If youve done your measurements correctly, the installation should be easy, according to Donahue. However, if you do find that you need help at any point along the way, he advises that you contact your suppliers technical support staff. In addition, his company offers Frameless Shower Door Guide, a volume of practical information concerning the installation of enclosures.
Regina R. Johnson is the editor of USGlass magazine.
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