Our house was built in 2016, shortly after moving in we noticed that all of our windows on the main floor leaked. The builder came, did something (I wasn't home), and all but one stopped leaking. It didn't leak often, so like a responsible homeowner, I am just getting to fixing it.
I inspected the leaking window and noticed there were gaps in the caulk between the board trim (see image below) and the window, so I re-caulked all the windows. Recently it rained, and now two windows leak (the one, and an additional one).
In the picture, we have vinyl siding, j-channel, board trim, window. I caulked between the board and the window. I am wondering if it shouldn't be caulked because the water has no were to escape if it gets behind the j-channel. thoughts?
Here is a picture of the water damage if it helps, the water oddly enough leaks on the same corner of all the windows, its always the left bottom corner.
Here are some additional pictures.
Best Answer
Gaps between the board and trim are normal. The standard way this is done is you have your siding in layers
Caulk can improve on this some, but properly installed windows like this should not need much, if any, caulk. Any water that gets behind your siding should be channeled down to the ground.
My bet is the window was installed incorrectly. A common area builders like to cheat on is wrapping the house wrap over the edges of the sill. That can create a pathway for water to penetrate the house. Caulk can't fix that either, since water is getting behind your siding.
Your best bet is to pull the siding off next to the window and make sure it's layered properly. Check the bottom corners if you can, since you typically need extra wrap there.