Your Guide to Choosing Kitchen Cabinet Doors

When it comes time to choose cabinet doors, it’s important to choose a cabinet door you’ll enjoy using and looking at regularly. Beyond appearances, however, it’s particularly important to consider how your cabinet doors are made, including how they’re constructed, the wood species used, and how they’re finished. Follow this cabinet doors guide to help you choose the right cabinet doors for you.

Cabinet Planning Guide: How Do Moisture Content and Humidity Changes Relate to the Life of Cabinet Doors?

When designed and constructed correctly, a cabinet door should be able to withstand changes in humidity and moisture. But in order to understand the reasoning behind the way cabinet doors are designed, it's helpful to understand how wood reacts to moisture.

The two "laws of physics" for wood are:

Law 1: An increase in temperature or humidity will cause wood to expand.
Law 2: A decrease in temperature or humidity will cause wood to shrink.

Because of these two laws, ALL cabinet doors must allow the pieces of the cabinet door sufficient space to expand when humidity or temperature increases. When humidity increases, the moisture content of wood will also increase. This increase in moisture content will result in the wood expanding. However, the expansion is not equal in all directions.

Width Expansion Height Expansion

Wood direction (and expansion) can be identified as "with the grain" (height), shown "Height Expansion" and "against the grain" (width) shown as "Width Expansion". The arrows indicate how the wood will expand as humidity increases.

For a given increase in moisture, width will increase by 8-12 times more than length, depending on wood type. Properly designed cabinet doors are constructed to allow for moisture changes. These pictures show the components that make up a standard cabinet door and highlights the raised panel.

From the expansion example shown in the cope and stick cabinet door above, it becomes clear that if the panel shown here were to expand, the frame of the door would be exposed to expansive pressures from the panel's increasing width. Without planning for the expansion that comes with moisture change in the wood, the expanding panel would either push the frame apart, or split the wood in the stiles (the frame's vertical parts).Obviously, a cabinet door that splits or is pushed apart in high humidity isn’t going to last well in most homes. As such, in the doors we build here at Cabinetdoors.com, the panel is allowed to float inside the grooves on the frame.

This picture shows two mitered frame parts, a rail (at left) and a stile (at right).Notice the groove, in both the rail and stile, which will hold the panel. The panel is sized to fit within the frame's groove, leaving a calculated amount of space for expansion. This expansion space allows the panel to grow or shrink with temperature and moisture changes, making a well-designed cabinet door dependable in all climates and regions of the country.

Mitered cabinet doors, like the Delaware Cabinet Door shown above, are a completely different frame design, but the moisture expansion compensation formulas still hold true. Because there is space left for the wood to expand, these doors are able to stand up to varying temperatures and humidity levels, for a long life.

Cabinet Planning Guide: Choosing the Right Wood Species

Cabinet doors used in closets, garages, and storage rooms are usually lower-cost woods, like paint grade and oak. Kitchens and baths, however, require a strong, durable finish, that can stand up to high humidity and temperature fluctuations, applied to a dense wood. Paint grade, alder, oak, or maple, are all great choices in a kitchen or bathroom. Alder, although classified as a hardwood, is not a dense wood, so while it may work quite well for entertainment centers and furniture, these are not subject to the moisture and cleaning seen in kitchens and baths.

You’ll want to choose your wood species based on how well it works in the environment you’ll be installing it, as well as how it takes the finish you want. Thankfully, you have plenty of beautiful woods to choose from at Cabinetdoors.com.

Cabinet Doors Guide: Paint grade

Painted cabinet doors are typically made from hardwoods with a closed grain. Examples of woods with a closed grain that paint well are maple and poplar. Oak is seldom painted because its open grain produces an "orange peel" look. Panels used in paint grade cabinet doors are usually Medium Density Fiberboard (MDF) because of its hardness, excellent sanding properties, and superior painting quality. Frames are usually made of poplar.

Cabinet Doors Guide: Oak, alder, cherry, maple, & hickory

These woods are seldom painted, partly because they are beautiful with a clear finish, and because they are more costly than other paint grade woods. Oak is usually stained or finished with a clear lacquer. Maple stains poorly and tends to look "blotchy", so it's usually finished with a clear coat, and not stained. Cherry can be stained light or dark, or simply finished with a clear coat. Alder and hickory, like Maple, are tight grained and stained adequately. They can be a little blotchy, but it’s less noticeable than trying to stain Maple. These two wood types are also often finished with just a clear coat over the natural wood.

Woods that have variations in density across a given board, like alder, maple, and hickory tend to develop blotchy patches when stained. Stain penetrates deeper into less dense areas of the board while sitting on the surface in the denser areas. This causes the less dense areas of the wood to produce a darker stained surface than the denser areas.

Cabinet Doors Guide: Which finishes protect cabinet doors best?

While almost any protective finish will provide better protection than leaving the wood unfinished, some finishes perform much better in harsh locations, like kitchens and baths. If you prefer the look of natural wood, a stain and clear lacquer is normally used to highlight the beauty of the wood. Oak is often stained, while alder, maple, and hickory are not usually stained since they tend to take stain unevenly. A clear coat of lacquer or polyurethane is always applied to stained or raw doors for protection.

It might surprise you to learn that painted cabinet doors require even more protection than stained or raw doors with clear coating. This is because a stained door will tend to hide slight scratches or dings suffered over time. If a frying pan bumps against a stained door, the damage will likely go unnoticed. With that same accident, a painted door will be less forgiving. For that reason, painted doors must be taken care of with caution. Paint touch ups are possible, but might be noticeable.

Cabinet Doors Guide: Conversion varnish

A product called conversion varnish is ideal for getting a painted finish that’s durable enough for use in the kitchen or bathroom. Conversion varnish was first used to provide a superior finish to manufacturers of metal and plastic parts. Using conversion varnish for wood products came a little later, but is now accepted as the most durable finish for cabinet doors used in kitchens and baths.

Conversion varnish is lacquer consisting of a high-end solid two-part post-catalyzed application process. At the time of application, a hardening agent must be mixed in with the lacquer to provide the additional durability. Conversion varnish is chemical-cured and consists of 40-60% solids. Conversion varnish does cost more than traditional lacquer, but it is much more durable and easier to clean. This makes it an excellent option for painted cabinet doors. At Cabinetdoors.com, we offer several colors of conversion varnish finish on a variety of door styles, so you can get a style you love in a color that will last.

A few examples of our doors painted with conversion varnish are pictured below. From left to right, these doors, finished with conversion varnish, are: The Heritage Cabinet Door finished in High Reflective White, the Shaker Door in Antique White, the Delaware Door in Light French Gray, and the Executive door in Folkstone. Click on these doors to see the price, as door sizes are entered.

Cabinet Planning Guide: Choosing Cabinet Doors

When you’re ready to choose cabinet doors for your home, you’ll want to pay close attention to how they’re constructed, the wood species used, and how they’re finished. Because finishing is so critical in slowing the impact of humidity changes on all wood products, it is necessary to apply a finish to your doors as soon as possible to maintain the quality of your cabinet doors. If you purchase unfinished doors, we recommend applying a finish as soon as you can, but within two weeks of receiving your doors.

As you can see from our cabinet doors guide, Cabinetdoors.com builds all of our cabinet doors with humidity and temperature changes in mind, so our doors are constructed to withstand the expansion. Just make sure you choose a finish that can handle it as well. Once you’ve settled on a style, wood species, and finish, you can order your doors in the sizes you need, and have them delivered directly to your door in a matter of a few weeks. Contact us if you have any questions, and we would be happy to help. When it comes to your cabinet planning guide, Cabinetdoors.com always delivers.