Find out where the water comes from and divert it away from the door.
It is obvious you have an architectural design problem since any
competent designer can produce plans that make such mistakes nearly
impossible. Your doorway might need a small portico or similar
building element that would both add to the curb appeal of the house
and eliminate the problem. Fiddling with the poor door and hoping for
future dry weather won't solve the problem long term.
The water comes from the air. The cause of the problem is that the installer
did not seal the end grain of the door which is allowing the wood to soak in
For now plane the door just enough to restore function, and when it dries
out when we get warmer weather then remove the door and apply some paint to
the top and bottom of the door.
If you are not part of the solution, you are not dissolved in the solvent.
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