The causes of the Leaky Condo fiasco are many and knowledge and experience exposes them. Further, from playhouse to skyscraper, all the same prevention measures apply. First, materials. Materials must suit the application for which they are intended. No longer is a building expected to last a mere twenty-five years. Nowadays, they cost far too much to build for this old-timey expectation. Heck, the modern home in the west will not even be paid for in twenty-five years. Some materials are unsuitable in some climates, particularly wet ones. Take stucco. Though it may offer many other practical and aesthetic benefits, as mentioned earlier, it is not necessarily impermeable to water ingress unless specially treated. And who is to ensure special treatment is perfectly consistent? Again, what system is inherently perfect?
To the rescue of this potential problem is the modern thinking that your siding, almost regardless of kind and type, is fallible; therefore, we will install another barrier beneath it that we do consider impermeable, or relatively so. This is the “Rain Screen Solution,” a notion that water will likely get behind a given siding type, but we will be sure that we do not impede its flow, ensuring instead that it drops harmlessly to grade. But, the membrane against a building’s wooden sheath is often tarpaper. Anyone who has observed tarpaper performance in rot scenarios knows that repeated exposure to water erodes it, turning it to flakes and powder. Similar complaints have been made against other backing membrane types, those used in lieu of traditional tarpaper.
In addition to material choices being problematic in terms of building health and longevity, design choices are often found to cause more problems than they solve. Flat roofs are a terrific example. When height restrictions are an issue, flat roofs are an immediate solution. They allow more living space beneath, which is always valuable, even more so in urban areas. Yet, is a flat roof a good idea in wetter areas? Some like to point out that much of North America’s coastal region is classed as rain forest, begging the question, Is a flat roof a good idea in a rain forest? One thread consistent throughout this discussion is that impeding the flow of water is potentially deleterious, operating contrary to building health aims. Yet, a flat roof will never drain as well as a sloped one, and though a flat roof does not necessarily impede H2O egress, it certainly slows it down. And certainly, when drains are not kept clear, the earlier-mentioned standing water encountered on flat roofs can occur, often to a level well over boot tops. Then, our roof membrane is the only barrier between the elements and a dry interior, a fact well known to the many who have suffered in such circumstances, in stand-alone homes, multi units, skyscrapers and playhouses all. Overhangs are another problem. Architect Frank Lloyd Wright is almost as famous for overhangs as he is for other aspects of his creations. Some would say they were excessive. Yet, looking at mud and other largely mud-made structures, substantial overhangs are crucial to building longevity. They exist mostly to counter the splash effect mentioned earlier, the idea being, of course, that the splash won’t reach the building base if the overhang protrudes adequately. And some of us thought these overhangs were intended to provide shade for siestas. Returning to more modern building types, the same applies. That eight inch minimum between your soil and your wood won’t be of as much use when the area is pelted by the splash effect because the building’s overhang does not project enough to give water a chance to lose momentum.