Being an inspector equipped with a highly advance thermal camera I have been called upon to find quite a few leaks.
Leaks can be very frustrating and challenging. Our modern, climate controlled, super insulated and immaculately finished homes do not respond well to storm water on interior surfaces. Window sills swell, drywall turns brown, and wood floors crack. How rude it is when Mother Nature invites herself into the world we control.
A very interesting pattern has developed after a few dozen, “….help me find where this leak is coming from,” calls. A majority of the calls that were related to storm water had three significant things I common: the leakage could be noted in a window opening, the window was on the south side of the home and the siding was a lap type.
With properly installed flashing homes should not leak. However it is nearly impossible to ensure contractors install something properly especially if it is above and beyond those minimum building standards some call ‘codes’. Caulking is always a good first line of defense but if the openings are flashed properly, caulking should not even be needed to keep the home water tight.
Before all of our modern, space aged materials it was common knowledge to crack open a leeward window in windy and wet conditions. With a modern understanding of hydro-dynamics we now understand that when wind hits a home a low pressure vortex is actually created inside the home. This means that in windy, wet conditions water is not necessarily blown-in but pulled-in. When the window on the leeward side of the home is cracked open, the pressures are able to equalize. Many intermittent leaks can be slowed, stopped or completely prevented.
If you do have a leak around a window or door, your flashing is not adequate and should be repaired. This can potentially mean thousands of dollars. In the mean time, if the wind is blowing rain at your home, try cracking a window on the other side of the home.