Wood Choice for Interior Doors

Pros discuss materials options for custom built pass-through doors. September 3, 2005

I have been approached to make 20 interior six panel doors. Each will be 8' tall and range from 2'-6" to 3' wide. All the doors will be painted. What type of lumber should I construct these doors from, which will hold up well?

Forum Responses
(Architectural Woodworking Forum)
From contributor E:
My wood of choice for paint grade would be poplar (American yellow). The price is good and stock is stable, but do not let machined parts lay around long prior to assembly.

From contributor O:
We have found poplar to not be stable enough for passage doors. We prefer to use soft maple, sometimes called silver maple.

From contributor Y:
I don't recommend using poplar for human doors. It is too unstable at this size. I always use eastern white pine for my human doors. I need the softer wood for hand planing because I do 18th century reproduction, but I know from experience if you make the door flat, that's the way it will stay. With poplar, if you make the door flat, you have to hope it will stay that way.

From contributor P:
We do quite a few of these - 20 today. We just cut the center out of regular paint grade slab doors and use 1 1/4 MDF panels with 1 1/4 MDF panel molding. They paint out nice. Why do you want to use solid wood?

From the original questioner:
The client asked for solid wood doors. If you can think of an alternative I can sell to the client, I am all ears.

From contributor P:
The selling points:
Less likely to warp.
Less labor/lower cost.
Looks the same after paint.
Masonite skins less likely to be dinged up over time.
Less material cost.

From the original questioner:
What is a good source for slab doors so you can start with a quality wood product?

From contributor P:
Everyone has them. I don't know where you are, but maybe El and El or Huttig.

From contributor G:
Poplar is great for interior doors. Even Huttig makes poplar doors. Yellow poplar is quite stable and makes great stain or paint grade doors. We have built hundreds of them and never had one come back.

From contributor M:
MDF doors will be the most stable for this application. They are made with much better quality these days, and with high-end designs. Jeld-Wen offers a good selection. For a local source on the east coast, contact Millennium Millwork in Edison, NJ.

From contributor B:
What type of assembly construction is going to be used? Are you all into the same method? This really matters if the paint grade doors are lumber core, MDF, or particle board. I once did a set of doors for a law office by ripping flush style birch veneer lumber core doors up and mortise and tenoning all so they fit well enough to stain.

From contributor C:
I have made many interior paint grade doors from poplar without a problem. The key is not to face laminate the stiles and rails, but to rip up the stock and build the stiles and rails from laminations, being cognizant of the grain pattern. Although I have been told it is not necessary, I joint and plane the material before gluing up the laminations to reduce stress. This process creates a very stable door.

From contributor G:
I fully agree with the comment above. We laminate all our door styles in a glue press. Sometimes we laminate the rails, depending on width. Makes a good, flat door that will stay flat.