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I’ve heard that epoxy grout is better for some types of tile installations. But I’ve also heard that it’s expensive and difficult to work with. Assuming all of these claims are true, when is it best to use epoxy grout, and what are the keys to working with it?

A.Michael Byrne, a veteran tile installer and consultant and the moderator of JLC’s ceramic tile forum, responds: In my experience, regular and latex-cement grouts can be relatively trouble-free — even in harsh environments — if they are used correctly.

For any grout, you need to follow the manufacturer’s instructions: Use the correct proportions of wet and dry ingredients (grout that is applied too wet is practically useless), fill the grout joints properly, clean with a minimum amount of water, and then allow the grout to cure completely before the tile installation is put into service.

That said, epoxy grouts generally have higher chemical resistance and are more flexible than regular cement grouts, which supposedly makes them more durable and more stain-resistant for places like kitchens and entry halls, and in commercial installations such as restaurants. However, epoxy grouts can be used on any interior installation and with any ceramic or natural stone tile (unless other­wise noted by the tile manufacturer). Most epoxy grouts clean up with water and generally do not need to be sealed after installation. They also usually cost more than other grouts.

In the past, I never liked using epoxy grouts because they were difficult to install and clean properly. The worst problem was that pinholes often appeared after the grout had been cleaned. This happened because many epoxy grouts sagged once placed in the tile joints, which forced trapped air upward in tiny bubbles. These bubbles always seemed to reach the surface just as the epoxy components began to harden, creating the pinholes. The pinholes were all but impossible to fix quickly because the leftover epoxy grout was too hard to spread to fill them. (I should point out that pinholes can also result from air escaping from under tiles that have not been bedded properly.)

Older versions of some epoxy grouts were also prone to discoloration when exposed to the ultraviolet rays in direct sunlight.

However, in response to concerns voiced by installers, many manufacturers have solved the problems that affected earlier versions. Through research and technological improvements, epoxy grouts are available that do not sag or discolor and that are much easier to install and clean.

In fact, some epoxy grout can actually be fun to use. Laticrete (800/737-8345, epoxy grouts outperform and are easier to work with than their predecessors. The fun part is that the company makes one additive called “Dazzle” that produces a bright metallic look, and another called “Glow” that — you guessed it — makes the epoxy grout glow in the dark.