As an artist builder, one of my signature details for the interior of our houses is a minimalist style. On some of the modernist homes we build, we are now doing the interiors with no trim at all. In this article, I describe how we go about creating an “invisible baseboard” to provide a seamless wall surface throughout the house.
Evolution. Back in the day when carpenters used hand tools, it was difficult to cut things perfectly, so carpenters installed what was often called “beauty mold” to cover imperfections and visually align building elements using offset reveals. This created an interior trim style that has become standard in most homes, and I started to ask myself, “Why do we keep doing all this trim?” Of course, interior trim has another purpose besides the visual alignment; it’s there to protect against impacts and to keep water off sensitive paper-faced gypsum. This is especially true of baseboard, which brooms and vacuum cleaners and skateboards and such bang into and where water from cleaning floors or wicking up through a concrete or tile floor could deteriorate drywall and create conditions for growing mold.
Reaching toward a minimalist style, we started ripping our trim down and evolved to doing flush baseboard that is recessed so it’s in the same plane as the wall surface, with a small channel separating the wood from the drywall. But I kept thinking there had to be something even cleaner than that. I experimented on my own home and developed a robust base treatment without wood that would seamlessly blend in with the wall surface and still resist impacts and water.
The “Dens-base” solution. We landed on using fiberglass-mat gypsum board in place of conventional paper-faced drywall for the first 6 to 8 inches above the floor. Fiberglass-mat boards, such as Georgia-Pacific’s DensGlass or USG’s Glass-Mat panels, are more resilient than drywall. I’ve done some hammer tests on these products and found the fiberglass-mat panels to be significantly stronger than drywall—and when the panels are backed up by the framing sole plate, they are extremely robust. You can dent them, of course, but the dents are a lot easier to repair than the ones in enamel-painted wood. Fiberglass-mat panels also resist water, although we avoid setting the wallboard directly on finished floors to provide both a capillary break and a clean visual separation between materials.
When we install fiberglass-mat boards, we hold them up about 1/4 inch (3/8 inch, maximum) so we can cap the bottom edge with a metal or vinyl L-bead. We play with the L-bead to create a nice, even reveal (ideally, I like to see 1/16 inch, but no more than 1/8 inch) between the L-bead and the finished floor. Ordinarily, we don’t caulk this gap. However, in wet rooms where we want to protect the underlying structure from water seeping back there, we will use tape to mask the edges of the gap, apply a clear caulk, and then sponge the bead smooth so it is slightly recessed below the surface, where it is inconspicuous and well protected.
Once the drywall is installed above the fiberglass-mat boards, we tape all the seams so the base panels disappear into the wall. We then finish the walls with Benjamin-Moore’s Scuff-X, a hospital-grade, low-VOC paint that comes in a matte finish and is super scuff-resistant. It not only resists marking but also cleans well, providing performance as good as or better than a semi-gloss enamel paint, which is what most people use for trim work. I especially like this solution because it saves considerable painting time not having to do all the setup, masking, and spraying for enamel work.
There is some extra time in getting the L-bead installed precisely, particularly around stairs. And we need to have our finish floors installed and protected before drywall. But overall, the cost of the invisible baseboard detail is a wash and often less expensive than wood baseboard.
