Soft Wet Window Sills

[whaas]

This may be completely impossible to troubleshoot but based on the experience level here somone may come up with something I haven't thought of.

I have 2 windows on the east side of my house that seem to capture more moisture than any other windows.
I checked the qualk on the outside of the frame and it seems fine.
The wood sill is soft and wet (not completly rotted). I can't figure out why.
The interior portion of the storm window glass is always frosting up in winter and in the summers months will have condensation.
The interior double hung portions doesn't necessarily have that moisture build up.

Please note I have windows on the north, south and west sides that do not have this problem.

[Windows on Washington]

I a window does not get good drying sunlight, you are hard pressed to eliminate water infiltration into a wood sill. That is just the unfortunate reality.

[whaas]

2 north facing windows in the next room get NO sun and have absolutely no moisture problems....even on the lower level I have another window north facing and it doesn't have moisture problems.

I wonder if these east facing windows have more / less air leakage causing the storm windows to frost up?

[TLHWINDOWS]

Could have some air/moisture leakage. Most likely trapped moisture in the wood and when the sun is first hitting them in the morning it is pulling the moisture out because the cold.

Just a guess though. Don't know were you live, but if you can open the window and try and and dry/air out the sill, that may help.

[buddy110]

The east facing windows get sun in the morning heating them up quickly. When warm air (the sun)meets the cold surface of your storms moisture forms and collects on the surface. In the case of your north facing windows (and the others) they "heating up is more gradual and the condensation evaporates before it can collect.

Just a theory

[whaas]

Good point...may be a combination of the air leakage and the quick warm up and quick cool down.

I have east facing windows on the lower level and they don't have the problem though. They seem to have a better seal.

I wonder is I should leave the storm window open a crack or even the window itself to dry it out?

[whaas]

If I end up getting these windows replaced...can I assume with a proper install with a high quality replacement this problem will go away?

The sill will then be vinyl so I'm thinking I don't have to worry about wood rot.

[HomeSealed]

The causes may not be completely be resolved, but the effects will. A properly installed and sealed vinyl replacement will just channel that moisture away rather than retain it.