Leaky Windows — Are We Blaming the Wrong Thing?

One area of the building envelope that catches a lot of grief for being a “leak” problem is the window.  However, most quality windows of the 21st Century are extremely well built and probably aren’t the cause of window area water and air leaks.  If windows are properly installed, the majority of the leaks blamed on windows will probably disappear.  We need to focus on the window rough opening to solve the problem.

MTI recently wrote an article on this issue.  Here are some of the highlights:

  • Exterior building envelope construction systems (roofs and walls) often fail in the detailing of openings, projections and transitions.
  • The need for holistic building is imperative.  Each party involved needs to know how their task, and materials used to complete that task, impact the final result.
  • When a potential problem isn’t addressed in one area, it often leads to failure in another.  A poorly prepared rough opening develops leaks that then get blamed on the window.
  • The bottom of the Window RO needs to be covered with waterproofing material that runs a minimum of 8″ up the sides; there needs to be a back dam; and the sill needs slope-to-drain to the outside.
  • There needs to be a drainage plane at the bottom of the window RO.
  • There needs to be a moisture diverter above the window RO that moves moisture away from the RO into the building envelope drainage plane.

MTI is not the only entity to have made these points recently.  Brett Newkirk, P.E. has authored an article in the Winter 2010 issue of Applicator magazine entitled “Forestall Sill-Flashing Failure.  His premise is that many of the techniques we are currently using to protect against moisture failure in and around the Window RO are actually causing the problems we are trying to avoid.

Below are some MTI drawings of the procedure for properly protecting the Window RO.  If you would like a copy of the MTI article by our CEO, John Koester, you can download it at http://www.mtidry.com/news/windowRO.pdf.


Things We Take For Granted

It is way too easy to get caught up in the negativity of the U.S. economy. One of the downsides to all the “connectivity” that most of us enjoy is that the message, whether good or bad, as thousands of ways to get amplified. Unfortunately, the media, as well as most of us, tend to feast on the negative, and we pass it around like a bad cold!

I would like to take a step back and ask you to step back with me. My guess is that most of you who have time to blog, Tweet, share on Facebook, browse the Internet, etc. probably have enough income to do so. Staying connected isn’t cheap. And if we can afford to do these things, we probably have work, a roof over our heads, heat and electricity, and enough to eat (probably way more than enough to eat)!

If you are one of the lucky ones who has all these gifts, how often have you stopped to think about how fortunate you are? I, like most others, get so caught up in what I want, that I rarely notice that I already have anything that I really need.

We just had our first major snowfall of the season in Northeast Iowa and Southeast Minnesota this past weekend. When I got up Sunday, I looked out my window and saw the scene in the photo below, and I thought “What do I possibly have to be griping about? I was able to sleep in a warm house, and the view I had out my window for free was better than most things I could find in an expensive painting!”

I know if you are in a construction-related business, times our tough, but if you are lucky enough to still be able to pay your bills, enjoy your family, and come home to a warm home, condo, or apartment, we really need to grateful. Those our my thoughts, I welcome yours!

A View of the Root River and Bluffs in Lanesboro, Minnsota

First Snowfall on the Root