Exterior Door Joinery

Ideas for detailing the joints on frame-and-panel doors for weather resistance. June 8, 2008

I'm building some exterior frame and panel doors, and was wondering how to deal with moisture accumulating in the groove of the bottom rail. I can make the panel fit very snugly into the groove, but moisture is going to get in there. Does anyone put weatherstripping in the bottom of the groove, which would serve as SpaceBalls and a weatherproof seal? What if you have panels that have decorative grooves in them - do you plug the little triangular holes?

Forum Responses
(Architectural Woodworking Forum)
From contributor L:
Finish the panel before you install it. And then finish it afterward. Make sure you use a film type finish to seal the door. Doors have been made this way for decades. You just need to use rot resistant species, and keep up with the maintenance on the door.

From contributor S:
This design of door is not ideal for full exposure externally. This design is covered by various standards, including a British Standard, which state that such doors should be installed into porches or under canopies. You could try bedding the panels into acrylic mastic/sealant (not silicone). This will act as a seal and allow sufficient movement to prevent cracking of the panel. The theory behind the design is that the surface finish seals the gap between panel and frame, but the only coating that is that flexible is chloro-rubber!

From contributor G:
I make mine like glass doors (profile on one side, glass shelf on the other). Then I put the panels in on beads from the outside after sealing everything. I apply some closed cell, sticky on one side, tape on the beads and compress it while micro pinning it (stainless). The tape compresses to 1/16" or so (3M). This lets the panel move, but not leak. Tried and tested in the very north of Scotland and on the Atlantic in New England. I have seen very well made traditional raised panel doors that were very well sealed act like a sieve if they were in an exposed place.

From contributor C:
This is a place where design trumps technique. If you're expecting the door to be rained on, you will have to redesign the rail/panel joinery. A ledge style door, or panels which are vertical battens which lap over a beveled rail (top) edge while tonguing into the rail behind the overlap are two ways. Old English joinery books are great resources for weatherproof construction.