Choosing Door Materials: Interior and Exterior Doors
Find tips and information on hollow-core flush interior doors, stamped interior hardwood interior doors, medium-density fiberboard, solid-core flush exterior doors, fiberglass, wood-panel, stave core, steel exterior and more.
There's more to your home's doors than wood and hardware. To make a structure that stands up to the weather and everyday life, doors are made with special materials and reinforcements. The way your door is made could affect how well it works and how long you can wait before buying a replacement. Read more below to learn about the different types and doors and how you know which choice is right for your family.
Because wood has a tendency to warp and to expand and contract with the weather, a door cannot be made from a single slab of wood. Centuries of experience have resulted in the practice of making doors from interlocking pieces. On a panel door you can see the rails, stiles, and panels. But even flush doors have frames and fill-in pieces, all covered by a solid piece of veneer. Some materials perform better than others; check a door's construction to be sure it will meet your needs.
- A solid-core flush exterior door is made much like a hollow-core interior door, but the space within the wood frame is filled with solid particleboard. These are very heavy but not as durable as other exterior doors. If not kept protected with paint, the veneer may delaminate from the particleboard. And if the particleboard gets wet, the door can become unusable.
- Fiberglass exterior doors are quickly gaining in popularity. Fiberglass is easily molded into most any shape and style. Fiberglass is durable, hard, and not prone to shrinking, expanding, or warping. These doors are available in a variety of colors and are easy to paint.
- Wood-panel doors, made for interior and exterior applications, have a classic appeal. Solid wood has good strength and insulating properties. Hardwoods such as oak are very resistant to denting; softwoods such as pine are more easily dented but are still quite durable. You'll pay more for a stain-grade door, which is made of full-length attractive pieces of wood. A paint-grade door joins together smaller pieces. All exterior doors must be protected with paint or finish to prevent them from warping or cracking. Some exterior wood-panel doors have a foam core, for added insulation and stability.
A stave-core (also called "core-block") exterior door looks like a standard wood-panel door, but it is made of several thin pieces of wood that are laminated together. The laminated core is then covered with a wood veneer. This method makes for an extremely stable door. However the veneer is liable to peel if the door is not kept protected with stain or paint.
Once considered an option only for commercial applications, steel exterior doors are increasingly popular for homes. Some have a steel face with a foam core for insulation. Others have a core made of foam wrapped in steel, with a wood veneer applied to the exterior. The result is a door with good insulating properties that is also very strong and burglar resistant.
Interior doors are protected from the weather so they can be made of less-substantial materials than exterior doors. Never use an interior door for an exterior entryway. No matter how well you protect the door with paint, it will warp and come apart in a few years.
- A hollow-core flush interior door is a common choice for new construction. It has a frame made of solid wood boards that are typically about 1 1/2 inches wide. A cardboard webbing runs through the interior to provide rigidity and prevent drumming. These doors can last for decades if treated gently, but can be dented or punctured if hit hard. A door with a lauan mahogany veneer is the least expensive but will soak up paint like a sponge. It often pays in the long run to buy a door with oak or birch veneer.
- Often the most affordable choice is a stamped hardboard interior door. The hardboard (sometimes called by the brand name Masonite) is a fairly soft material, but is usually covered with a hard-baked paint. The hardboard can be molded into a convincing approximation of natural wood grain. Some hardboard doors are hollow-core, while others are filled with foam or particleboard. These can look great for years if treated gently, but they are easily dented; if they become wet for prolonged periods, the hardboard will swell. Both conditions are difficult to repair.
- Interior doors made of medium-density fiberboard (MDF) are gaining in popularity. Many of these doors have a paneled yet modern look and are available in a wide range of attractive styles. MDF is harder and less susceptible to denting than hardboard, though not as strong as solid wood.
Glass-paneled doors need to be well built, especially if they are exterior doors. Individual glass panes are often referred to as "lights" (or "lites"). Be sure to get gas-filled thermal glass panes for an exterior door, and make sure the glass is well sealed against the stiles and rails.