“What causes most roof leaks?”
Summary:
Jeremiah identifies improper installation as the number one cause of roof leaks. He argues that even the most impressive material, whether rubber, slate, or cedar shake, means nothing if it is not installed correctly, and that thousands of dollars spent on quality material is wasted without correct workmanship. He explains that roofing uses a hidden fastener system with very specific nail patterns, where the next shingle should overlap the nails so water never reaches the nail head. If nails are driven within the keyway where shingles meet, water can flow around the nail head and cause a leak, typically surfacing about five years later. He also flags accessories and protrusions such as pipes, fans, and ventilation systems, where nail patterns must be exact. Finally he stresses using ice and water shield in those areas, a sticky adhesive material that seals around a nail head when driven through, which he considers essential for valleys, protrusions, and the perimeter.
Answer:
So what causes most roof leaks based on my experience would be improper installation. That is the number one reason that a roof will leak. You can have the most profound material out there. Rubber roof, slate roof, even cedar shake. If it's not installed correctly, it does not mean anything. You could spend thousands and thousands of dollars on a good roof material, but if it's not installed correctly, it's not going to last. The key point with this is when you're installing a roof, there are very specific nail patterns that you need to follow so no water can reach that nail head. It's all a hidden fastener system. So where you put the nails, the next shingle should overlap that so the water never reaches the nail head. But if they're nailing within that specific keyway where the shingles meet up, water can flow around that nail head and can cause a leak. Typically it will take five years before that will happen, but it is a very serious thing that can occur. The last thing I'll add to this is where the accessories are in the roof. So whether there are pipes that come out of the roof, fans that come out of the roof, or ventilation systems, the nail pattern around those areas needs to be very specific so no water can flow around those nails. And when you have those protrusions coming out of the roof deck, is the roofer that you're choosing using some sort of ice and water shield around those areas? It's not specifically that we need to worry about water damming up too much here. Maybe for two weeks in Washington, that's what we need to really worry about. But those areas where the ice and water shield is applied, it's a sticky adhesive material that when you drive a nail through it, it seals up around the nail head. Very, very important for those high risk areas like your valleys, your protrusions, and around the perimeter. The areas that receive more nails definitely need a material like that that will protect it for a longer amount of time.