CMI manufactures both CraftMaster^® molded door designs and finished doors.

CMI operates door manufacturing facilities throughout the country that manufacture, sell and market CraftMaster molded, stile and rail, and flush doors. See CMI Information or Contact Us for more details.

How CraftMaster Molded Door Designs are made into CraftMaster Molded Interior Doors

Doors made with CraftMaster molded door designs can be manufactured with hollow core, semi-solid or solid core construction. CMI recommends solid core construction.

Doors Constructed with a Hollow Core

As you can see, the construction methods shown vary. In this example, the Carrara door features corrugated honeycomb core material, while the Colonist door showcases standard corrugated paper blocking.

Typical materials

Stiles and Rails: Wood or Medium Density Fiberboard (MDF), 1 1/8" wide before final door sizing.

Blocking/Pads: Cardboard or EPS (Expanded Polystyrene or Styrofoam). This component is typically 1” wide, 12” long in the windows (see figure).

Lock Block: Made from particleboard and occasionally from wood, in the following dimensions: 3” x 6”, 3” x 8”, or 3” x 10.”

The majority of doors sold today have a hollow core. This does not mean that the interior of the door is empty. Instead, it means that the core material does not comprise the entire door cavity. Hollow core doors do not provide the same weight and feel as a wood door, and do not offer sound deadening protection.

Doors Constructed with Semi-Solid Core Construction

The following diagram illustrates typical semi-solid core construction. Pieces of particleboard or wood blocking are used instead of corrugated paper or EPS (as in a hollow core door). Typically, the core material pieces are much larger in size than in a hollow core door. This type of construction is not very popular since the cost is close to that of a solid core door. A semi-solid door offers a more pleasing, solid weight than a hollow core door.


Doors Constructed with Solid Core Construction

Doors with a solid core more closely replicate the weight and feel of solid wood doors. The solid core material provides the door with enhanced dimensional stability, support and durability. In addition to the pleasing weight and feel, doors with solid cores also act as better sound insulators than doors with hollow cores. Sound Transmission Coefficient, or STC, is an indicator of a given material's ability to act as a sound barrier. The higher the number, the better the performance. Solid core doors will perform 15% better in this category than hollow core doors.

The following diagram illustrates solid core construction:

Typical materials

Styles and Rails: Wood or treated wood, 1 1/8" wide before final door sizing.

Core: Possible core materials include particleboard, mineral core, or wood stave core. The illustration above shows the cut-out or routed pattern to allow the panel configuration to fit inside the core.

Hollow Core vs. Solid Core

The following charts give comparative data showcasing the differences in weight and STC values for hollow core and solid core doors. As you can see, there is a considerable difference between a hollow core door and a solid core door.

Approximate weights for 1 3/8” thick doors
Type of Door Construction	Door Size 24” x 80”	Door Size 30” x 80”	Door Size 36” x 80”
Hollow Core	23 lbs.	28 lbs.	32 lbs.
Solid Core (28 lb. PB)	47 lbs.	58 lbs.	71 lbs.
	Door Size 24” x 96”	Door Size 30” x 96”	Door Size 36” x 96”
Hollow Core	29 lbs.	38 lbs.	46 lbs.
Solid Core (28 lb PB)	60 lbs.	75 lbs.	90 lbs.

STC values for 1 3/8” thick doors
Hollow Core (30” x 80”)	27
Solid Core (30” x 80”)	29