THE ROOFING
INSIDER
Drip edge is one of those roof components that often goes unnoticed by homeowners which is probably leading you to ask, “What is drip edge, and what is its purpose?”
I know it looks childish, but this is possibly the best illustration I have ever found to describe the adhesion and cohesion properties of water. Adhesion causes water to stick to other surfaces, while cohesion causes other water molecules to stay attracted to one another.
Now let's tie this together to explain what drip edge does for your home. As water runs off your shingles, not all of it drips off that 2-inch overhang.
Since water has strong adhesion forces, some water will want to stick to the underside of the shingle and run back UP the shingle towards your home.
You might think it's hard to believe water running upwards, but roll up a paper towel and stick the tip of it into a cup of water. That water runs right up that paper towel (by the way, this is how plants work: sending water from the ground up to the top).
I know, I know, I'll stop with the science.
So now water is running back towards your home on the UNDERSIDE of your shingle. EESH!
Without drip edge, the water can penetrate between your shingle and your roof decking causing your roof deck to rot. It will also then begin making it’s way into your fascia causing it to rot as well.
Drip edge catches that water traveling on the underside of your shingles and diverts it downward, off your roof, and onto the ground.
I mentioned "purely functional" before because a lot of trendy homeowners might choose a certain type or color of drip edge to compliment the color pallet of their home and or roof.
Don't rob yourself of knowledge! Here are some more helpful articles to improve your basic knowledge of your roof.