My house is 12 years old. Two winters ago, my bathroom window started to leak. I could tell because the bathroom is above my kitchen and all of a sudden I started to get water spots on my ceiling. The window only leaks when there is a wind-driven rain. How can I tell if it is a weep hole problem, a glaze problem or if I need a whole new window? What is a retro fit window versus a replacement window? Thanks

 

Do you have brick mold wrap around the outside or your window? Most do.If you do remove it, if you have wood siding up against the window, cut out 1 1/2 inches around the window ( save the wood ) when you remove this you can see the nail fin of the window, check for proper caulking and flashing.

I've seen a lot of builders that forget to caulk or think it's not needed because they flash. Sometimes the rough opening is a bit to big and the nail fin doesn't cover like it should leaving unnailed holes exposed to the unside of the house.Caulk everything , empty nail holes, edge of nail fin to building, the fresh cut siding and replace the wood siding you removed ( so the depth still matches the rest of the windows ) caulk the siding you put back to the house siding and window. Replace brick mold.

Another thing I would look at 1st is the roof.Check for water stains in the attic ( and it doesn't have to be directly over the window in question )
Water can travel long distance down truss , wall, over a bit and down the wall again, making you think it's the window when really it's the roof.

Look for cracks in the window frame, if cracked, sometimes it can be repaired and or caulked.

I kinda wrote this back wards ( meds = type before thinking ) so check out for cracks and roof leak, then think about looking at how the window was installed. If the weep are clogged, clean them out.

One time I fixed a whole house package of windows because the builder put them all in upside down

 

Thank you for your advice on the window. We actually did think it was the roof (there is a small individual roof out over where the water spots were showing up). We had that small roof replaced and when the next storm came our problem was back. I forgot to mention that my house is stucko. Since I can't cut away any siding and put it back what do you suggest?

 

check for cracks and pin holes where the stucco meets the window frame and caulk where needed Permacink (sp) comes in colors to match stucco and looks like stucco.
If someone else other than you replaced the section of the roof, and your %100 sure it not coming from there I would still check. Put a sprinkler on the roof in that area and soak the heck out of it, while it's still running go up there and check. I would also go back to the builder, depending on the brand of window a lot of them have life time warranties ( if you bought the house new and your the first owner )