We changed our window 3 years ago as it was leaking following a bathroom remodel. Today I saw black watermarks on the window panel and wall. Is there a way to fix the leak or any idea from where water might be leaking? It is supposed to rain later in the day.

 

Of course your window is leaking from the outside and has been for some time. I'm concerned about rotting and mold behind the wall considering the extent of the visible damage. I'd remove the window, repair the damage, reinstall and seal the window.

Don't just seal the window. The damage has been done.

 

Thanks! The installer is expected to show up later today. Let me see what he says.

 

The channel the window is sitting in concerns me. it looks like a head expander. Those go on top of the window not on the bottom. What does it look like on the outside? That's what we need pictures of since that's where the leak is occurring.

 

Here is a picture of the exterior...

 

First, if the siding wasn't removed when the window was replaced that's part of it. Windows with nail fins need to get incorporated into the WRB (housewrap) so that IF there is a leak, the water doesn't come in. If the replacement window didnt have a fin, that's strike two. Windows should never rely on just caulk to keep water out. Caulk is not a primary installation method.

Secondly, vinyl siding is not waterproof. Water gets in around the edges of the j channel. When it gets to the bottom, that water is now behind the siding. So a window with no fin- or a fin that was not taped to the WRB- will leak. If there is a window above this one, the window below inherits the water from above.

Third, there appears to be some custom aluminum cladding around the perimeter. That can and usually does leak... or at least it traps water and does not promote drying. When you remove aluminum cladding you often find nothing but rotten wood.

Fourth, where the Palladium window and the Double Hung meet, there is a mullion. That can leak.

And finally, I can't see the bottom of the window where that piece on the inside is that I asked about. If this is a retrofit window (no nailing fin... and thus the installation relies primarily on caulk to keep water out) the bottom of the window will be the primary place where that caulk can fail and cause a huge problem. Or if the window was set inside the head expander, (like I'm afraid of) then it's basically like your window is sitting in a bathtub.

Only other thing that it could be since you mentioned this is a bathroom, is that hot humid air does not play well with cold glass or drafty window perimeter. It's possible that lots of condensation on the inside has caused the water you see on the inside. For instance, sweat running down the windows in the wintertime. If the window isn't level, it all runs to one side.

 

Each side of the window is a path that gravity will use to carry any water, from the siding above the window, to the ground. These paths, where the siding meets the window trim, needs 100% sealing, especially on the oval, to prevent the water getting behind the siding and causing wall damage. Also, is there a way for water coming through the screen to drain at the sill? It looks like water has accumulated in this area in the first pic.

 

You do NOT caulk inside the j-channel at all. Water gets behind vinyl siding. That's why a WRB is needed and the window gets sealed to that. The vinyl siding can leak all it wants, that's how it works.

 

XSleeper, please explain the downside of using caulk in the J channel. We know nothing about the house construction or the window install.

 

What we do know is that you don't caulk inside j channels. That is bad advice which I'm obligated to point out.

Vinyl siding has to be free to move or it will buckle and warp. Plus if you have caulked up the j channel if and when the guy has to come remove siding someday to remove or fix the window, (you need to use 4" tape all the way around the nail fin and expose the entire top of the Palladium window in order to be able to fold up the WRB above the window and tuck under it) you would destroy the siding if it's been all caulked together. Now you have to find new siding that matches (it wont due to color fading). You should be free to replace any piece of siding anytime without damage. Can't do that if it's caulked.

Caulk also dams up any water from above that is already behind the siding looking for a way to get out.

As I said, vinyl siding is meant to let water behind it. It's 100% on the WRB to prevent the house from getting wet. That's how it works. That's why properly installing a window is so important with vinyl siding. So if you have a window that is improperly installed and not sealed to the WRB it can and probably will leak.

 

We had the installer's guy come in yesterday. He opened up the siding on the top of the window. He showed us that the nail fin was incorporated into the WRB. He also checked to see if it was wet inside, but it was dry. He then added some sealant where the windows are mulled. Only other thing could be condensation as it is a bathroom window...It has been raining the entire night yesterday and today as well. So far there is no moisture/wetness on the sill (I placed a piece of toilet paper on the window sill at night and have been checking it..). Hope its stays that way!

 

Still curious what the bottom of the window looks like on the exterior side.

 

If the dark marks on the window trim and the lower panel (in second photo) appeared in 3 years, it is not from humidity unless someone is using the shower most of the day. I also believe silicone sealant is flexible and will continue to use it on my projects. WRB has 2 different meanings, water-resistant barrier or weather-resistant barrier. Which one did the installer guy mean?

 

2 different meanings? They are the same thing, called by different names.

Also, regarding condensation, you should live somewhere it gets cold. Really cold. Then you would know how much cold windows can sweat. I once replaced an entire house of windows in a new house... they were only 10 years old. They sweat so much in the winter that it ruined their oak trim. And this was not just in the bathroom. The whole house was that way.