Commercial Wood Doors
Commercial wood doors are 1 3/4" thick and can be solid core or hollow core. If you are installing the door into a hollow metal frame, it will always be 1 3/4" thick. 1 3/8" thick woood doors are usually used in residential prehung units which consist of the door already installed in the wood frame with the hinges. It will be prepped for a lock which will be installed on the jobsite. Prehungs with 1 3/4" thick doors are very common in commercial applications.
Hollow core wood doors are obviously never used at exterior openings and are usually used at interior residential although they are also sometimes used on commercial buildings because of their low price. The majority of prehung units we have supplied over the years have been solid core since we deal in commercial doors. If the door is going into a hollow metal frame, it will almost always be a solid core. This type of door is available in either stave or particle core. Particle core is the most common as it is less expensive than the stave core which is a solid lumber core door. There has been a lot of improvement with particle core doors and that is generally what is called for now when solid doors are needed.
Although wood doors are available in many types of veneers, the most common are oak, birch, hardboard, and medium density overlay (MDO). Oak is good if you are staining the door although birch is available in a stain grade and is less expensive. Oak doors usually are not painted as the grain will show through afterwards and if you are going to cover it up with paint, you might as well go with a cheaper veneer.
Wood doors are available in fire rated (up to 90 minutes) and non fire rated. Keep in mind that the cores on fire rated wood doors are different than a non-fire rated wood door. In hollow metal doors, the core stays the same (except in temperature rise doors), with the only difference being the size of glass you are allowed for each different fire rating. Fire rated wood doors can get a bit expensive due to the type of core required. If you are going to paint the doors in the end, you may want to consider hollow metal doors if you need fire rated doors and need some "value engineering".
We keep paint grade birch wood doors non fire rated in stock. We have these wood doors in stock machined to match our hollow metal frame hardware locations and we also have slab wood doors that we can machine to your specifications. We are fully equipped to machine these wood doors to whatever you may need. All fire rated wood doors and other species besides birch are special order.