A Question of Weep Holes

Shelter magazine recently received the following letter from a reader:

I am a small wood window manufacturer in the Midwest. I have had a problem on new-framed unit windows where casing and sills rot prematurely. The common denominator on all of these problem houses is they have flush mounted (chanel) combination storm windows. The weep holes are very small and located 4-5" from each end of the sill expander of the storm window. They are also caulked at the bottom from the interior -leaving a 1/4" space at the weep holes. Any water that gets in and doesn't reach the weeps, just sits in our wood frame and eventually evaporates or freezes.

I can not find many articles on this subject, but have looked at many other brands of wood & aluminum storm windows. They all seem to do the same thing: small weeps(to improve air infiltration numbers) and holes that are so far from the ends that they might as well just put one in the very center. This seems like a very important clash of design purposes. I give my frames a 14 degree pitch to shed water, but the storm manufacturer wants an "airtight" window so the smaller weep the better. For this to work, storms should be 100% water tight, and do not allow homeowners to open them. I have even looked at full screen surrounds that have no weeps. I think designers feel that standing water on sills will just evaporate out the screen.

If you have any advice or referrals at all, I would love to hear from you. This must be happening to other manufacturers. I am absolutely confused at why such a simple thing is not being addressed.

Alex

Do you have any advice or insight to offer Alex? If so, please contact Shelter magazine editor Samantha Carpetner at scarpenter@glass.com.