I've installed a few prehung exterior doors over the last few years, trying
to flash and caulk the doors as best as possible. Unfortunately, none of
these doors have roof overhangs to protect them from the weather, and storm
doors on the outside are not an option.
In almost every case, there have been problems with leaking and/or rot, and
now I need to repair or replace the door frames.
The door frame assembly really seems like a dumb design in the first place.
It relies on the caulking/sealant between the sill and door jambs to
prevent water from coming in, and then the wood sits right on the sill to
wick up moisture.
If I can find some place to order them, I'm planning to replace the rotted
door jambs with jambs that have a PVC bottom section to prevent the wicking
issue (like the "EverJamb" at http://www.evermark-lnl.com /), then
installing a sill pan under the jamb (like the "Jam Sill" at
www.jamsill.com). But these still seem like work around fixes to an
inherent design flaw.
So, I'm curious if anyone makes a one-piece door sill with upturned edges?
Then the door jamb could overlap the sill edges, keeping the bottom off the
sill to prevent wicking. Wood doesn't touch water, and there's no where for
moisture to go but out. It seems like such a basic flashing detail to me,
rather than relying on caulk between the jamb and sill.