Baseboard moldings are decorative trim boards that cover the seam, or joint, between an interior wall and the floor. Baseboards have three important jobs: they hide the gap between the wall and floor, they protect the wall from damage, and they serve as decoration (in more important ways than you might imagine). Thanks to their role as room decor, baseboards come in many different types, sizes and styles. The right baseboard is one that suits its application and the other decorating elements in the room.
The Architecture of Baseboard
Walls have baseboard moldings partly for the same reason that classical columns have a base: we like our structures to have a solid-looking foundation. If you can picture a wall with a substantial baseboard along the bottom as well as a crown molding at the ceiling, you can see parallels between a decorated wall and a classical column, with the crown molding serving the same purpose as a column's capital.
We also like our spaces to have definition. A baseboard is a strong horizontal border that helps to define the large wall area above and even to highlight the decoration on the wall surface, much the way that underlining highlights a written word or title.
Mind the Gaps
When drywallers cover the walls of a new house with drywall, they don't run the drywall all the way to the floor. They leave a gap of about 1/2 inch, for a couple of reasons. The gap provides room for the floor structure to move (even the tiniest amount) without applying upward pressure that could crack the drywall. The gap also simplifies drywall installation, as drywallers use a simple levering tool to lift up the drywall so it's tight against the ceiling, leaving the gap at the bottom. Without the gap, they'd have to cut each piece to fit and carefully nudge it into place.
Baseboard covers the gap so no one's the wiser. It also creates a little channel that's handy for hiding telephone wire or computer or TV cables. But this is not a good place to run regular electrical cable (and also contrary to code) because its higher voltage makes it more dangerous if someone unwittingly drives a nail through it.
The many scuffs, dings and chips that baseboards inevitably show over the years are proof of the protection they provide to a wall. Bumping a vacuum into a solid baseboard may leave little or no trace, but the same impact directly against drywall would almost surely make a dent. The thickness of baseboard also protects the wall from collisions with furniture. On the flip side, sometimes this can be an annoyance when you want to push a bookcase or another piece furniture flush against the wall, only to find that the baseboard prevents it.
Baseboard can be grouped by how many pieces it consists of. The most common type in modern homes is a single flat board with a simple decorative profile or round-over cut into its top edge. Rooms that have wall-to-wall carpeting usually include baseboard by itself, and the carpeting actually tucks under the baseboard. The trim carpenter, knowing that the room will be carpeted, leaves a small gap between the baseboard and the floor for just this purpose.
In rooms with hard-surface flooring (tile, vinyl, wood, etc.), baseboards usually run all the way to the floor. After the finish flooring is installed, a thin strip of decorative trim, called a base shoe, may be applied on top of the flooring and up against the baseboard—as sort of a baseboard for the baseboard. Base shoe is flexible enough to follow contours in the flooring to hide any gaps.
In older homes, baseboards were commonly built up from multiple pieces of trim. A standard design starts with a wide, flat board for the main baseboard. This might receive a base shoe at the bottom, a decoratively profiled cap piece along the top, and perhaps a half-round bead or two running along the face of the main baseboard. More elaborate versions may include a single large baseboard with a decorative top edge (or cap) covered with a second, narrower profiled baseboard in front, a base shoe, and perhaps additional applied moldings.
Historically, the style of baseboard followed the style of the home, but these days baseboard moldings are pretty generic. Most homes built since the 1960s have single-piece Ranch or Colonial molding. Ranch-style baseboard is a flat board about 2 1/2 to 3 1/2 inches wide, with a simple, rounded top edge. Colonial-style baseboard is similarly sized but has some type profiled top edge, the most common being the Roman ogee shape.
Common historic styles of baseboard include the simple, tall, dark-wood boards used in Craftsman-style bungalows and the equally tall but ornately decorated (and often painted) baseboards used in Victorian homes. In almost all houses, modern and historic, the styling of baseboard moldings typically matches or complements the styling of the door and window trim, or casing.
Baseboard moldings are sold in four groups of materials: softwood, composite wood, hardwood and plastic. Chances are, you can find the size and style of baseboard you want in any of these materials. The decision regarding which wood material to choose usually comes down to whether the trim will be painted or stained. If you're painting the molding, there's no reason to spend the premium on a beautiful hardwood, unless you really want the durability and general ding-resistance of the harder material (and even so, painted softwoods are easy to repair because you can fill in dents and paint over the patches). Hardwoods, such as cherry, maple, oak and walnut, typically are reserved for baseboards that are stained or protected with a clear coat, both of which show off the wood's coloring and grain patterns.
Softwood materials, such as pine and aspen, are less expensive than hardwoods and are the cheapest when they are _finger-jointed_—in which long lengths of molding are made up of short pieces bonded together with interlocking joints. If you're painting the wood anyway, there's no reason not to save money and use finger-jointed material.
Composite molding typically is made with medium-density fiberboard (MDF) and may or may not have a thin outer coating of plastic or other material. MDF baseboard is relatively inexpensive but requires a bit more care during installation. Cut edges must be sealed so they accept paint well, and, if the material is coated, the coating can be damaged during cutting and nailing. Composite baseboard is designed to be painted.
The chief advantages of plastic, or polymer, baseboard are low cost and, in many cases, flexibility. Many plastic moldings can be bent to follow curves and contours in walls and floors. Large or elaborate baseboards that are cost-prohibitive in solid wood may be much more affordable when made from plastic (or composite) materials. Plastic baseboard moldings to avoid are the really lightweight, almost foam-like materials with a faux-wood coating. These may have their place in motorhomes and temporary buildings, but they never look like the real thing; go for paintable material instead.
Philip Schmidt is author of Install Your Own Solar Panels, The Complete Guide to Treehouses, and 18 other home-related how-to books. A former carpenter, he has been a full-time writer and editor for over two decades, teaching DIYers about houses and everything we do with them.