External Threats – The Rebel “Alliance”
The Death Star was supposedly indestructible. Nevertheless, in the end, they were reduced to space rubble. Your roof is just as vulnerable; it may seem strong and sturdy, but no matter how expensive or well built your roof is, there will always be certain factors that can attack your roof at its weak points and cause considerable damage. Here are some of the most seemingly innocuous, yet dangerous, things that can pose a threat to your roof.
You may wonder how something as puny as raindrops can bring down a roof. While rain usually runs down the roof and straight into the gutter harmlessly, it will penetrate the roof surface through any gaps it can find, no matter how small. This could be caused by a missing shingle, a punctured roof deck, or wide seams between roof panels. However, the biggest danger from rain, which you can spot easily, is pooling water.
If you see areas on your roof where puddles are forming after hard rain, there is something wrong. This is particularly a problem with roofs that have a shallow pitch, or have a lot of peaks and valleys. Water sitting on the roof will find its way into your home eventually if it remains there for any length of time. The cause of this could be the rafters or sinking sheathing. This can be because there is already water damage coming from a leak, or the roof was improperly installed.
From there, rainwater can cause all sorts of moisture-related problems. This includes having nasty water rings on your ceiling, mold formation, and wood rot or corrosion, which can compromise the strength of the roof supports and cause the roof to implode on itself.
Wind also likes to exploit weaknesses in your roof, but unlike rainwater, the damage can be instantaneous. The wind tends to lift the roof up, causing the entire roof to blow off in some cases. Wind acting on the roof surfaces causes negative pressure that creates the lift. Additionally, the roofs overhang creates strong uplift forces. For a hurricane-resistant home, the length of the overhangs should be limited to around 20 inches.
One would think that gravity alone would be sufficient to prevent the roof from detaching from the rest of the building. The power of the wind in more extreme weather events such as hurricanes is quite immense, and once the roof is lifted, the entire structure is at risk of catastrophic failure. This is why many buildings are destroyed during a storm.
If you think that the Death Star analogy falls short because you think your roof isn’t a weapon of mass destruction, wait until it blows off and lands on your neighbors! Additionally, once the wind damages a roof, it is easier for rainwater to get inside and cause long-term damage, the wind and rain working hand-in-hand like the Rebel Alliance.
Some pests can slip by unnoticed like Obi-Wan, others are furry like Chewbacca, and some move as swiftly as the Millennium Falcon; all of them can spell trouble for your roof. Rats and termites can chew on and punch holes on the outer roof surface, while birds that nest on or inside your roof system can clog air vents and corrode parts of your roof with their litter. Making sure your roof is safe from pests is just as important as protecting it from the weather.
You know the threats and why they should be stopped, but how do you stop them? Find out in Part 3, the last part of this blog series, coming soon!