Acrylic is glass-block alternative

High-density urethane is being widely used to produce architectural elements once carved from wood or sculpted from plaster.

Now, another kind of plastic -- acrylic -- is being used to manufacturer faux glass blocks. Clear or tinted in trendy hues, they are, like other plastic alternatives, virtually indistinguishable from the real thing.

That, of course, begs the question: "Then why not use the real thing?" The chief reason may be weight. At up to 70 percent lighter than glass, acrylic blocks can be used to make operable windows and as inserts in doors. Conventional glass blocks are too heavy for those kinds of applications.

Also, while blocks of both materials can be used to build partitions, the weight of glass blocks in substantial quantities can require reinforcement of the floor. That's much less likely with blocks made from acrylic.

Another advantage of acrylic block may be the ease of installation. Traditionally, glass-block walls have been assembled -- by a mason -- one block at a time, using mortar to bond the individual blocks together. It can be a time-consuming and expensive process. Walls made of acrylic blocks, on the other hand, are usually made of pre-assembled panels fabricated at the factory.

Like glass blocks, those made of acrylic come in a variety of sizes. Both are valued for their ability to provide varying degrees of privacy and light transmission at the same time.

That semitransparent quality makes both glass and acrylic blocks ideal for a wide range of in-home applications, including:

• Interior walls and room dividers. In a home with an open floor plan, a glass- or acrylic-block partition can define and separate spaces while allowing light from one room to penetrate through to another.

• Exterior windows and window walls. From the inside, the blocks can blur an undesirable view of the back of your neighbor's garage while allowing space-expanding daylight to stream in. From the outside, they can provide the privacy you need when your bathroom window faces your neighbor's house.

• Kitchen backsplashes. Just two or three blocks high, sections of glass or acrylic inserted between the countertop and the wall cabinets can enlighten work surfaces and brighten an entire kitchen. With the addition of rope lighting, the blocks can even be used to make an illuminated enclosure for an island or peninsula.

• Shower enclosures. The irregular but smooth surface of the blocks sheds water as well as solid glass panels or ceramic tile, but is better at minimizing visible water spots and streaks. Better yet, they allow natural or artificial light to drench the shower enclosure while providing privacy.

Prefab shower enclosures made from glass blocks are available from Pittsburgh Corning (www.pittsburghcorning.com). Those made from acrylic blocks are available from Hy-Lite Products (www.Hy-Lite.com).

• Stairwell railings. Glass or acrylic blocks can provide a visually compelling alternative to conventional spindles without compromising safety.

• Color. Blocks in green, blue, peach or rose offer even more decorative possibilities because natural and artificial light gets tinted as it passes through them. Because the intensity of the color varies with the intensity of the light, a room can change moods throughout the course of a day.