Let’s be honest; decks built over dwelling areas are an architectural design nightmare. Roofing Brisbane Specialists will tell you that the most challenging problems they experience are leaks resulting from layers made over lower-level dwelling or garage areas. These leaks are difficult to diagnose because there is commonly more than one source of moisture entry, and troubleshooting the leaks can become quite complicated.
Of the more than 700 managed properties my company services, more than half have second-story patio decks. Most of these decks are built over bedrooms, living areas or garages. All of our properties with this design scenario may experience leaks during storms.
One common misconception about such leaks is that they originate from the failure of the decking membrane. Membrane failure ranks fourth on the list of sources of moisture intrusion. Having repaired thousands of deck area leaks, I’ve learned that the cause of such holes is usually one of the following, in order of probability:
Decks have an access door, which is generally a sliding door on an aluminum frame. These frames are built much like a picture frame and commonly fail at the lower mitered corner joints. Repair requires temporarily dismantling the door, reinforcing the failing joints and improving drainage of the threshold system.
2. Wall flashing
Hose bibs, electrical outlets, light fixtures and windows adjacent to the deck are the sources of many deck area leaks. Even a thimbleful of water penetration at these places can show up on the ceiling below. While urethane caulking can help remedy wall leaks, it is sometimes necessary to rebuild the poorly-flashed walls. In the case of stucco walls, they may have to be coated with elastomeric coatings.
3. Base-metal, perimeter-flashing
Decking must be separated from perimeter walls using metal flashing. Where this flashing meets door … Read the rest