Henry Staggs, RRO
May 10, 2020
Moisture The Enemy
The first job of the roof is to keep the water out, right? If the roof provides all sorts of other benefits and leaks, what good is it? The number one reason for a roof leak poor workmanship. After that, its some other kind of sudden damage. The lack of maintenance, or the roof is old. We can control the workmanship with detailed specifications and quality assurance. Uncontrollable damage to the roof is covered by insurance. A lack of maintenance it's very easy to control. But is often neglected. We can't make a roof not get old. But the better the roof is taken care of, the longer it is likely to last.
A leaking roof will do a lot of damage, and not all at once. Water can do its destructive work overtime when you do see a sudden leak. The damage that caused that has long been in progress. Whatever your insulation is, water will destroy its effectiveness. The decking, metal or wood, will deteriorate. Fasteners will rust. Mold can find a place to grow on wet materials. Of course, the roof system materials will degrade and ultimately fail.
Let's go inside
The first job of the roof is to keep the water outside. When it fails to do that, and several things can happen that are not good. Remember, in our article about MOLD? Spores are everywhere, waiting for a place to land and grow. Wet building materials offer them a lovely place to grow. After a while, the air quality will go down and start smelling musty. The materials will begin to change the size. Causing all sorts of movement problems and begin to fail. With the right amount of moisture metal, fasteners will rust. And then you'll have some huge issues. As you see, keeping the water outside is very important. The long term cost of a leaking roof is like throwing money away.
The roof always gets the blame.
Not leaks are roof leaks. The building is one thing, consisting of many parts, all working as one. One component could be failing, and the wrong component gets the blame. For example, your water source could be from the ground. Or the plumbing is leaking. It could also be a ventilation problem.
Hot air is wet air
Nothing is better than a nice hot and steamy shower. Right after, you have to wipe the moisture off the mirror. That's why we have a vent fan in our bathrooms, right? Its nice while we are in the shower. Considering the roof's job is to keep the water out. That applies to the inside moisture having a way out. Vents through the roof are one of the more vulnerable areas of a roof. This is a point when good design and skilled workmanship are fundamental. Be sure the vents won't be a source of a leak in the system.
Moisture can't stand the pressure.
Warm holds more water, but air can only have so much before the moisture wants out. On a hot, humid day, the air feels heavy, like its sticking to your body. Making it harder for you to cool off and feel comfortable, right? Well, it feels that way because it is that way. The more moisture the heavier it is. Moisture will travel from a high-pressure environment to a lower pressure environment. Guess what? That hot stick air outside is trying to get inside to your nice cooler lower pressure building.
The design of your roof and the entire building envelope is essential in keeping the moisture out. The design must address both the exterior and interior moisture challenges. It takes the knowledge that a good roof consultant or building envelope consultant. A change in the use of any given building can affect the way it will handle the moisture challenge. Not to mention how it will affect your air conditioning systems. And its ability to keep your interior comfortable.