Exterior door with 2x4 jamb in 2x6 wall

Old 02-16-19, 12:13 PM
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Exterior door with 2x4 jamb in 2x6 wall

So I bought doors for 2x4 walls but my builder did 2x6 walls. So i need to make up the difference. I thought jamb extensions would be straightforward, but the hinges actually extend into the area where the jamb would be. I could just mortice a spot for the swell of the hinge pin but that would limit the full opening of the door. I was thinking about stepping it out to the level of the interior wall with some sort of molding like a bed or shallow crown. Anyone have ideas or experience?
Old 02-16-19, 01:03 PM
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You always install doors with the hinge side of the jamb so that it is flush with the wall on that side. Any jamb extension goes on the opposite side. And you can often get a 2" sill nose extension for the sill if your door has a slot in the front of the sill to accept one.
Old 02-17-19, 08:11 AM
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I agree with X for interior doors. Exterior doors however bring the added issue of weatherproofing so an external jamb extension may not be suitable.

I had a similar situation to yours when I had a contractor build a vacation home weatherproof shell that I finished inside myself. He installed all the exterior doors in 2x6 and 2x8 walls with the jambs flush to the outside. When I finished the inside I installed the jamb extensions on the outsides of the jambs. See sketch below. Where there was sufficient space between the jamb and the studs I overlapped the extension. Where there was not I rabbeted the extension jamb to fit. In all my cases the doors opened against walls (90 degrees) so the hinge position relative to the jamb was not a problem. Doors opening fully will encounter interference at the hinge with an interior jamb extension.

Another consideration is that a flush interior extension will be struck by the latch. An extended latch plate or other protection will be needed. The photo below shows that situation where the trim was extended out only 3/8 inch. Stepping the extension back will avoid that.
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