What is a hollow core door?
As the name suggests, a hollow core door is mostly hollow in the middle. Hollow core doors usually have a solid interior frame that runs the entire perimeter of the door. That frame is sandwiched between two thin veneers sometimes called skins. The skins can be flat/flush, or they can be molded to resemble a traditionally made panel door. The frame can be made from solid wood, hardwood, MDF, particle board, or a combination. The frame is often thicker where the door handle, lock, and hinges are located.
In addition to the frame, there is a honeycomb or grid structure made of thin wood or cardboard that adds strength to the panel and prevents the two skins from collapsing in on each other. If the surface of the door is flat, the door skins are probably made of plywood or hardboard. If the surface is molded to look like a raised panel door, the skins might be made of fiberglass or some sort of plastic.
The main advantage of a hollow core door is price. Because they are easier to make and contain less material, they cost less than solid core doors. And due to their light weight, hollow core doors are easier to lift, move around, and install than heavier solid core doors. And if installed using less-than-best practices, they are less prone to get out of alignment if repeatedly slammed by the wind or a moody teenager than a solid core door.
Due to their lightweight construction, hollow core doors provide little security from forced entry. If Jack Nicholson’s character in the movie The Shining would have been barred by a hollow core door, Shelly Duvall’s character would not have stood a chance. Hollow core doors don’t do a good job preventing the spread of fire, don’t block sound very well, and just don’t feel as substantial or durable as solid core doors. Each raised panel hollow core door requires an expensive mold to create, so there aren’t as many configurations to choose from.