Hello,

I have a few questions about storm windows that will hopefully be easy to understand with the pictures below.

1. We placed a bead of caulk on the edge of the storms before attaching them, but we did not caulk on the lower edge of the storms to avoid moisture problems with the weep holes. To prevent air infiltration, I'm thinking of caulking the lower edge of some of the storms from the inside. My question is, is it ok to caulk here, or is this is a no-no due to moisture issues? What about the sides of the inside of the storm?



2. Where exactly are the "weep holes" on a storm window? And are these holes supposed to be cut through all the way into the window, or are they just cut on the storms themselves?

Here's a picture of how the storm is installed from the outside:



Here are my guesses as to where the weep holes are located, with the holes circled in red:



Here's a close-up detail of the same picture above:



I'm guessing that the only holes that are really weep holes are the ones that look like vertical notches at the very bottom of the storm window. Do these notches need to made in the window frame also to prevent moisture build-up?

And what in the world are those round-holes for? Are those also "weep holes"?

Thank you for any help with this!

 

Yes...all those are all weep holes. You could caulk between the "slots" on the flange, leaving about 1" on each side free of caulk, and wiping it well so you don't leave a big bead.

The round holes are for any water that may leak into the track that the window sash fits into when closed.

If you put caulk under the mounting flange on top and sides..thats good.

Personally, unless those are very good quality storms..I wouldn't bother with doing anything else. The cost of the caulk will be more than you save by preventing any small air leakage, and it could cause water damage in a bad rain. I'd leave it alone.

 

Thanks for the info, your explanation on the weep holes was great.

I'm not sure I understand what you're saying about the caulk between the slots on the flange. Is the flange the very bottom part of the storm window that includes the vertical weep holes? So you're saying I could caulk between the slots on the inside or outside of the storm window?

Thanks again!

 

Yeah, the flange is the flat part all around the outside that is screwed into the window frame. All I meant is that if you do caulk, either inside or outside..just make sure its a small "divot"..not a big glob that would restrict any water migration.

Again, you'd probably be better served adding ceiling insulation or sealing outlets and switch boxes or weather stripping doors.

 

Caulking storm windows on is rarely a good idea. First, it makes the storm window difficult to remove in the future without bending it all up. Secondly, the issue of creating a dam on bottom will lead to rotton sills, even if you leave the weep holes open. And third, in some cases, storm windows will fog up in the winter time if they have been caulked on.

Storm windows are not meant to be completely weather tight, they do need a little fresh air to breathe. These comments come from nearly 20 yrs in the window business.

 

I said that X..or was I not clear enough....durnit! I'll do better next time!

 

No, I know! I thought maybe this was a case where a couple voices saying the same thing might add a little weight to the advice.

If a guy would caulk the bottom expander, even if you would leave the weep holes open, it's going to hold water behind the sill expander at the corners, eventually forcing that trapped water down between the jamb and the sill, or making it wick up the blind stop like a straw. It also makes it less likely that any water that does get under the expander will dry out. Having replaced many rotton wooden window sills, I can tell you it's best to leave them completely uncaulked.

 

I've been told by numerous contractors that caulking the storm windows on is ok as long as the bottom is uncaulked.

Here are a few links I found that recommend caulking:

Weathering the Storm | Windows | This Old House - 1

How to Install a Combination Storm Window : How-To : DIY Network

XSleeper, do you think I should remove the caulk that is currently in place? I definitely don't want rotten sills! What do you think? Thanks.

 

Well, X isn't here..but I always seem to be. Caulking is a personal choice I think. I agree that just top and sides is best. If you partially do the bottom you would need to be very vigilent in your maintenance, checking for water retention, paint or wood damage and clogged weep holes.

X mentioned it can be a pain to remove the window later, but I don't think most people take the storms off all that often.

As I said, if they are quality storms it may help somewhat, but if they are the typical off the shelf units from HD or Lowes, they really aren't all that air or watertight to begin with.

 

Thanks gunguy, I think I'll take your advice and just keep a close eye on things. I've learned a lot about storms from you and XSleeper. Thanks again!