Water - one of the great mysteries of life; Life itself isn't possible without it. Yet from the time of Noah and his ark, water has sometimes been a nuisance of great proportion.
There are three very common types of water leaks that affect our homes: water that leaks from a neighbor's apartment because of overflows or pipe breaks; water that drips, drips, drips from kitchen faucets, bathroom faucets, and toilets; and water that penetrates the building envelope and seeps inside through walls and ceilings.
Of these, the last of the three aforementioned - water that penetrates the building envelope - is perhaps the most frustrating to homeowners, management, and building staff. It can be a huge challenge to locate the point (or points) at which the water is penetrating the building.
Simply put, the building envelope is that part of the building that separates you from the outside elements. Outside walls, roof, windows, and doors are all part of the envelope. Any opening in the envelope can be a potential point of water entry. Once the water has breached the barriers designed to keep it out, it can travel quite a distance, both horizontally and vertically. So just because a water leak has terminated at a particular point in your apartment - your living room ceiling, for example - does not mean it came directly from above. It may even have traveled hundreds of feet horizontally before moving vertically and seeping through your ceiling. Water travels the path of least resistance, so its route through a building can be complicated.
Keeping in mind that your building's roof, bricks, and windows are designed to keep water out, so what does go wrong? The building envelope fails for five basic reasons: