Casment window-leak question

[jaynews]

Question: If a casement window is dripping water from the gap at the top and the water gets between the inner and outer sash, is likely this would cause the water to get behind the drywall and onto the floor?

Reason I'm asking is because, about 10 days ago after it rained, I had water on the floor, and the drywall around the window corner was moist when probing with moisture detector. (but the sill did not seem wet, and the wallpaper was not wet) I wasn't in the room when the leak actually happened though.

I don't know who makes these windows. They are aluminum clad with no markings. The outer frame and outer sill is aluminum, but the inner sill and inner part of the sash is wood.

Today it's rainy, I'm noticing that water is dripping from the gap at the top, so now I'm SUSPECTING this is what happened last time (dripped from the gap at top into the gab between inner and outer sash).

However, I'm afraid to conclude yet that this is the same exact thing that happened 10 days though. Yesterday afternoon I tried squirting water from an empty shampoo bottle directly into the gap at the top and I wasn't able to get water to drip down the gap into the inside. And I suppose that maybe my testing yesterday got the seal wet "primed it" to make drip through the gap at the top this time. But I agree that the seal (V-type flap that fits in the kerf on top of sash) has flattened out since I installed it last spring. I will put some D-Seal rubber weather-strip underneath to give it upward pressure. If water getting past the top seal is cause of what happened 10 days ago then hopefully this will solve it.

Other thoughts:

I also notice that the association didn't caulk the gap where the siding meets the top of the window. An engineer told me that there really should not be caulk there because if water should ever get behind siding then it would have no place to escape except inward. But I'm wondering if not having it caulked there could also cause a leak if enough water gets into that gap.

I tried to get the association to install drip caps last year, and the property manager agreed to do it, but the workers did not want to take siding off (even though they were replacing other wood that was rotted at various locations). The lack of a drip cap doesn't seem to be helping matters. These windows have a metal frame that sticks outward a little, but no drip cap, and I'm told they have a flange underneath the siding. Do you think I should have the association caulk the gap at the top where the siding meets the window frame, even though an engineer says that's not the right thing to do? Do you think I should push to have drip caps installed?

Thanks,

J.

[jaynews]

I meant to say "between inner and outer sill" in first paragraph.

[Eric in North TX]

Any chance you just need to clean your gutters? My first house was like that, if it rained and the casement windows leaked, it was time to clean the gutters.

[jaynews]

This is on the side of the building. No gutters there.

J.

[Goedjn]

Generally, the bottom sill is a solid peice, and sloped out, so that any water that penetrates the window structure itself is dumped under the window, back outside. I suppose it's possible that the sash-to-sill is making such a good seal that the water has to get out by running under the side-rails and thus into the wall cavity, but it seems more likely that you're getting water behind the siding and/or in around the window trim that's travelling around the window along the rough framing.

Open the window and look carefully at where the sill dissappears under the rails. Caulk or paint that crack. If that doesn't solve the problem, then the water is probably getting in farther up the wall. At that point, test by spraying water down at the top of the window. If THAT doesn't generate water, but rain does, you're probably going to have to open the wall to see where it's coming from.

[jaynews]

On this particular window it appears that it has:

1) The inner sill which is the lower side of the wood trim that surrounds the window on all 4 sides inside the house. (Sort of like a giant fat picture frame on the inside.) 2) A horizontal block of wood further outward, which is at the same level as the inner sill. The inner frame that holds the crank sits mostly on top of this block of wood (that I'll refer to as #2). 3) Then, further out there is the outer sill which is aluminum clad. At start of the outer sill is a lip in the aluminum that sticks up holding a gasket pointing outward. 4) There is a gap between block of wood (#2 above) and the outer sill (albeit small). There also appears to be a gap between that block of wood and the inner sill as well. There are gaps on the sides of that block of wood as well, between it and the vertical blocks of wood that exist on the side of it. There are also gaps between the outer jambs and the vertical blocks that I just described.

Key Question: Lets say water drips down from the gap at the TOP of sash and then drips onto the gap at the BOTTOM sash. Seems to me that it could easily hit block of wood #2 (especially since there is the gasket touching inner window frame). Once the water hits the inner block of wood #2, then it could get into the gaps between it and the outer sill as well as the gaps between it and the inner sill, etc. Could water getting into these gaps cause it to get behind the drywall and then the floor? Unless there is some (totally hidden) mechanism to direct the water back outside if it got into the gaps surrounding block of wood #2, then I'm not seeing how the water could get back outside, and this could potentially explain why it got behind the drywall, could it not?

Just seems to me that once water gets further inward then the aluminum clad part, that the water simply isn't going to be making its' way back outside the house, the way this particular window was designed. Does that sound right? (Again, this is an unlabeled window from an unknown manufacturer.)

Thanks,

J.

[Goedjn]

I can't make any sense of your description, but yes, if there's a water-path through the sill, that's bad.

[jaynews]

Basically I'm saying that it appears there 3 pieces of the sill. An inner painted wooden part (visible inside the house), a middle wooden part that just looks like a piece of bare wood, and then the outer part which is aluminum (or aluminum clad).

Seems to me that water, if it dripped down from sash gap above and eventually ran onto the middle piece of wood, it could then got into the gaps between the other two parts of the sill, or the gaps at the ends of this piece, then perhaps it could make its way under the drywall instead of running outside the house. (especially since the outer sill has lip sticking up that is higher than the level of the middle piece.)

Seems these windows were designed so that if anything ever gets past the seals then it's staying in the house. But to be sure, then I'd have to squirt water onto the middle piece see what happens but then I'd be getting the drywall wet again (etc.) which likely isn't a good thing to be doing.

J.