Passage door construction

Techniques and joinery used in the construction of passage doors. January 3, 2001

I am looking for resources on door design and construction. Where should I start?

Forum Responses
It might be nice to brainstorm this issue a bit. When still in the business we made custom frame-and-panel doors for local residential customers and builders.

Typically, we built from hardwoods like cherry or oak using 5/8” panels back to back for the thicker entrance or passage doors. We used standard cope and pattern shaper tooling with heavy-duty shapers running 1 1/4” spindles and an air assisted coping fixture. We developed a system of dowelling that made for very tight joints and fairly easy assembly in the small production shop environment.

I’d be interested in what others do for large door joinery. Are any of you using traditional mortise and tenon joinery? Slot mortising? What kind of machinery and clamping equipment are you using?

Typically, for custom interior doors, we have been asked for 1 3/4" thickness. We use a mortise and tenon construction, but with cope and stick cuts. Tenons run 2 1/2"-3" in length. We only use the long tenons on the rails. On intermediate stiles we cut the short 5/8" tenons. We also use two 3/4" panels back to back. I use a Maka mortiser and a Wadkin BEM shaper for the tenons and panels. I made my own tenon fixture for the BEM. The tooling is not quite off-the-shelf, but the tenon disks are. Profiles are standard. We use a JL Lancaster frame clamp for assembly. And to sand it all up we use a Tagliabue 37" two-head wide belt. Probably not the most cost effective method, but it makes a bullet-proof door! And since most custom doors are high-end, this seems to be what customers expect. Most of these orders are for 7'0" and 8'0" heights.

I think the first post has the right idea with the male and female pattern plus dowels. That’s typically how most doors that I have used are constructed. Most of these doors, as well, tend to be custom and are 7’-0” or more in height as opposed to 6’-8”. Likewise, pretty much all commercial stuff is at least 7’-0”.

Making house doors is completely different from making cabinet doors. The same basic principles apply, but with the addition of dowels and heavy equipment. You cannot make house doors on your router table with some off-the-shelf male/female router bits from Freud. You are also dealing with 8/4 material for the frames vs. 4/4 in your cabinet doors, with the addition of either a thicker raised panel or a two-piece panel.

Are you going to supply the doors finished or unfinished? If you are going to do the finishing in house, are you prepared for the additional material handling in the finish room? If you are planning on supplying them unfinished, then when a problem arises over a warped door, who’s responsible--you or the finisher? And I won’t even go into the exterior side of this equation, that’s a whole other subject (I can hear the worms squirming). I don’t want to discourage anyone from trying to make their own doors, but I would like to point out that doing so is a whole other ball game than making cabinet doors.

Brian Personett, forum technical advisor

I've built quite a few doors and have been working with #20 biscuits along with stub tenons and have found them to be quite effective. On an 8/4 door, use three rows of biscuits and a 1/2" thick by 1" long tenon clamped up with pipe clamps, type 2 glue, and I doubt that you'll have any problems.

It's nice to have all the big equipment, but you don't have to. I've made a lot doing it this way and have great success. Some doors as large as dbl. 10'x4', 2 and 1/4" thick solid mahogany. And even in the extremes of Florida (30% humidity in the winter to 100% in the summer) they have held together completely, some as many as 14 years so far.

The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).

Comment from contributor R:
I have been quite happy with my front door which I made using my router table and table saw. The design includes three layers of 3/4 oak. The inner and outer layers are complete raised panel constructions, and the inner layer is simply a 5 inch wide frame. This design allows for a 3/4 inch sheet of uranyl acetate foam, foil backed (r7 per inch) to be placed in the "core". The whole affair was simple glued up with all the clamps I could find. Three four inch ball bearing hinges and a commercial Schlage L type mortise lock finished it off. I built the jambs with 2x8 oak, finger joined, including the threshold, which I beveled. The door has stayed flat with about a sixteenth, and I think the laminated construction contributes to its dimensional stability. It was a bit labor intensive, but it has a rather pleasing sound when it closes.

Comment from contributor J:
A nice addition to standard cope and stick technology is to use Festool dominos instead of dowels. The dominos have a much better glue surface, and in my opinion, are just as strong as or stronger than a deep mortise and tenon, when you factor in the inevitable differential movement of a deep mortise and tenon over the years.