Interior door construction

[ohlund]

I'm interesting in building some interior doors and have two concerns.

First, the plans I've got show the kickplate (bottom-most rail) at 9" wide and secured with dowels (as well as with glue, I assume). If I just use glue on 9" cherry, am I going to have problems with cross- grain on door rails (the stiles)? Is glue adequate?

Secondly, if I just make a single raised panel for the top panel of the door (versus several smaller panels separated by stiles) will I encounter movement problems even floating it in rails/stiles? I notice that commercial doors with single panel seem to all be composite (e.g. MDF) and designed for paint only versus solid wood.

Thanks for the help.

~Mark.

[dadiOH]

Lord, NO! Tenons or dowels are needed. ___________

What's going to move?

I made all of mine with a single top panel. Doors vary from 24" - 36" wide.

[Leon]

If the top panel is solid wood, it is going to contract and expand with humidity and temperature changes, not so much if you keep the environment controlled. If you often leave your exterior doors open and it is humid you are going to see movement.

[Leon]

Will you have problems with the door? Probably. Is glue adequate? Probably not by it self. I'd not build the door with out dowels or tennons they add the strength needed when the wood does eventually move.

Probably unless you use plywood or MDF panels.

I notice

Yeah, there is a reason for that.

[ohlund]

A wide, solid wood panel "floating" between two outside rails will move proportionately more than a narrower panel. A single panel will only have area for expansion provided by rails on either side. Multiple panels will have area for expansion provided by rail on either side. Two panels will have twice the expansion area provided by the rails as a single panel door will. My concern is that with a 30" door and a single panel on the order of

22", do I have to worry about movement causing problems?

~Mark.

[SonomaProducts.com]

I would think door construction would be mortise and tenon, not dowels. They take a lot of racking forces from opening\closing and hanging from the hinges. I haven't built any doors that size but it seems I have seen lots of examples with M&T joints.

Yes, I would build in an allocation for movement. I wouldn't woory too much about a 9" width of cross grain for expansion if I used yellow glue but I would woory about a butt joint with dowels in a condition where it has dynamic loads.

I built a screen door with triple doweled butt connections when I first started out and it failed in a few months. It was exterior and slammed a lot but that is just a faster test environment to what an interior door will have to handle over the years.

BW

[Leon]

A wide, solid wood panel "floating" between two outside rails will move proportionately more than a narrower panel. A single panel will only have area for expansion provided by rails on either side. Multiple panels will have area for expansion provided by rail on either side. Two panels will have twice the expansion area provided by the rails as a single panel door will. My concern is that with a 30" door and a single panel on the order of

22", do I have to worry about movement causing problems?

YES. Now whether you consider panel movement a problem is up to you. If you varnish and the varnish gets down in the groves that the panel fits in, the varnish could effectively glue the panel in place causing it to not "float" if the panel contracts you get a split in the panel. My front door has this problem. If you do not pre stain or varnish the panels before assembly and if your panel contracts it exposes an unfinished area where the panel fits into the stiles.

[dadiOH]

Yes, I know but OP seemed worried about making one panel vs two. Both are going to move but - assuming there is enough "float" in the rail & stile grooves - it doesn't matter whether one panel or two moves. N'est ce pas?

[whit3rd]

The usual approach would be to make two or three 2" tenons instead of a full 9" wide glue joint. If you have a full door of cherry, I'm not sure how dowels could hold the joint against that weight...

Cross-grain gluing of a relatively narrow (2") tenon should be safe enough. Loose tenons (use a router to make pockets on both rail and stile) are easiest.

Unless you have wide boards available, the 'single raised panel' will have to be glued up. Your wood can be prettier if you select strong grain patterns and put no joints in midpanel, which leads to small panels.