It was a brand new house with a shingle roof. It also had a complicated roof design and six valleys. The builder went a little too far cost-cutting and hired a couple of day-laborers to shingle the house. He had paid them just $10 per square for 30 squares, a total of $300. All was fine and dandy until the first rain… when all six valleys leaked!
Of course the day laborers were long gone by then, which is just as well according to Einstein. He said that some problems can’t be solved with the same mentality which created them in the first place! This was one of those problems.
That’s when the builder called the small, but reputable roofing company I worked for.
The valley errors were all pretty obvious… and typical of the ones that rookies and poorly-trained roofers make. I will say this for them… they were consistent. All six valleys had exactly the same problems. And all six had to be completely re-laid, costing the builder more much more than he paid for the entire roof.
One of your biggest challenges when roofing your own home is the valleys. After repairing hundreds of them over the years, I see the same mistakes over and over. Here are the three most common problems… and how to avoid them!
How to Install Roof Shingles – Valley Tip #1
Valleys fill up with water during a big shower and some water ends up under the shingles. If the shingle nails are too close to the center of the valley, you can get a leak. That nail pattern you see on the shingle wrappers doesn’t apply to the valleys. Keep your nails at least 12″ away from the center of the valley.
How to Install Roof Shingles – Valley Tip #2
Shingle seams can also leak when they fall right in the valley. Keep the seams at least 12″ away from the center of the valley by adjusting the length of the adjacent shingles on both sides.
How to Install Roof Shingles – Valley Tip #3
When cutting the top layer of shingles in a “half-weave” valley, many roofers cut into the bottom layer. Over the years, those cuts can open up, causing leaks. Make the cut carefully with some old tin snips, or use a hook blade and a scrap shingle to protect the bottom layer.