Exterior door rotten wood

[westneck37]

I have rot at he bottom door casing. What is the proper way to investigate the origin of the leak?

 

[CharlieO]

Is the rot that you're referring to on the bottom door casings is that interior or exterior door.

What is meant by proper way to investigate the origin of a leak. what kind of leak are you referring to.

 

[westneck37]

These are french doors, one opens inward the other is passive. The one that opens has a storm door and had no rot. All the rot is on the passive side.
The rot is on the outside casing and brickmold, Both the brickmolding and casing are destroyed for about 6 to 8 inches from the bottom.
When it storms there is a collection of water under the carpet opposite the rotted areas
There are 3 large custom windows directly above the doors that leaked on the inside until they were treated two years ago. Could they still be the problem on the outside?
I have repaired the door frame but I'm still not sure I have corrected the source of the problem.
I removed all the rotten wood, replaced it with new wood then covered the repair with new brick molding and casings.
Each peice of wood that I applied was caulked throughly before adding another so that every joint in the new work is primed, sealed and caulked.
I noticed that the threshold moved slightly when I caulked it so I'm not sure the caulking on the threshold was affective and could have been the problem.

Waiting for the next storm to see if the problem is corrected.

Thank for any additional suggestions for where the water might be entering the door frame.

 

[joecaption]

I've yet to see a sliding or french door installed the right way, or have it properly maintained.
There should have been a sill pan under the doors threshold.
Jamsill Guard Door & Window Sill Pan Flashing

Within 24 hours that door frame and door should have been painted.
There should have been a piece of vinyl lumber installed under that threshold to stop it from flaxing on the outside wall tight up againt the bottom side of the threshold.
Any new doors we have been ordering have soild vinyl jams, and vinyl brick moulding. Yes they will cost more but only having to buy one door for the rest of your life will make up for it.

Most of the time when a door fails and there's inside subflooring damage it's because the stoop, deck, porch was built so it's even with the door opening.
A guarrentyed way to have it fail. It should have been at least 4" below the threshold. A standard step is 7" so that would have been the best height.
There is no good way to just patch up your old door and not have it show. By now not only is the brick moulding and jams rotted there's damage to the subflooring under the door.
No form of caulking or wood filler is going to fix the real cause of the problum and waiting to see if it works is just going to end up costing more money and time.
Just step on the threshold and twist your foot, look in the corners of the threshold and you will see the threshold flex and the seam in the outside corners will open up.

 

[joecaption]

I'll try this again. If there's a stoop, deck or steps right up to the bottom of any wooden door jam, there will be rot If someone buys a new door and does not paint it ASAP with two coats of acrilic latex paint it will rot, doors are shipped primed, not painted in most cases.
If the door was installed without the propper support under the outside of the threshold on the outside where it over hangs the outside wall the threshold will twist and flex causing the sealer in the outside corners to crack and allow water to hit the end grains of the wooden jams.