Have you ever replaced an expensive section of roofing or decking, only to discover that in the next rain, it still leaks? Do the same leaks show up year after year, even though you have paid premium prices for emergency repairs on the same section of roofing or siding? This is a common problem facing homeowners associations in Southern California. The real question is, "How do you facilitate an effective repair?"

It helps to first understand the nature of roofs, decks and wall leaks. The easiest method of identifying leaks is to understand the principle of flashing. Flashing is a consistent pattern of construction, which simply means to overlap what's below with the component directly above.

If I could choose a mascot for my company it would be a duck. Yes, a duck. This is because a duck's back never gets wet because its feathers are so perfectly placed. A duck's feathers effectively shed water because feathers above overlap feathers below. Therefore, rainwater runs from one feather to the next and cascades off its back. The same is true with the components of a roof or wall, whether shingles, siding, windows, vents, drains, etc. All components installed must overlap or flash those directly below. If they don't, leaks will occur.

Now that we know why leaks occur, what's next? To illustrate this let me take you to a homeowners association that we serve. Summerwind is a 500-unit complex of town homes located in Torrance, California. The board of directors was frustrated due to the problem first outlined in this article, paying for expensive repairs to roofing and siding and experiencing the same leaks year after year. At Summerwind, the previous roofer had replaced sections of tile roofing and caulked the heck out of the siding, windows and flashing pieces at great expense but the leaks kept repeating. After identifying their most common problem, we asked to examine the most problematic unit because often the worst leaks are the easiest to troubleshoot. We then proceeded with a proven three-step scientific process. Scientific, in this case, means simple.

Step One: Water Testing
Water testing doesn't mean that you flood the entire area above the leak and prove that it does indeed leak. We already know that it does. That is why we are here. Correct water testing requires stages that focus on individual sections of the building shell. The lowest possible point of leaking is tested first for approximately 20-30 minutes, long enough to know for sure whether it leaks or not. If no leak occurs, the testing is raised onto the next overlying section. This process is repeated until the leak is recreated. Water testing is successful in pinpointing the exact point of moisture intrusion 95 percent of the time.

The water testing at Summerwind started on the lower section of tile roofing. After 30 minutes with no water intrusion in the entry ceiling, the testing area was moved to the wall below the window, then onto the window, then to the wall up to the roof transition. On the fifth stage of testing, the leak quickly appeared.

Step Two: Invasive Repairs
During step two, the section of flashing failure is carefully dismantled until the failure is evident. It should be understood that water-leaks always leave substantial evidence. This is in the form of staining, heavy dirt build-up, rot and rust, which make for dramatic photographs. After identifying the failing components, the roofs or walls are reconstructed in a correct manner.

At Summerwind, when the walls and roofing-related flashings were removed, it was evident why leaking had occurred. Many of the components were not overlapped. Heavy soot build-up in the wall insulation caused by the filtering of air-born pollutants in the rainwater was proof of the source.

The wall and transitional flashing area was rebuilt using upgraded #30 pound felt underlayment, and the critical transition areas were flashed using a pliable membrane called Melroll. All siding and roofing were replaced in weatherboard fashion with correct overlapping and guess what? Next storm, no leaking occurred!

Step Three: Effective Preventive Maintenance
The information gathered from the previous steps gives you the ability to proceed with effective preventive maintenance for the remainder of the complex.

In the case of Summerwind, this meant that a simplified process was adopted that has been applied to all other leaking entry-units with no callbacks. Yes, not one.

Effective leak analysis and repair can be an easy process where the homeowners association can understand the failure and finally experience peace of mind when the next storm occurs.