Shingle Roofing: Repairing Valley Leaks in 6 Easy Steps

Though roof valleys are common leak sites on shingle roofs, it’s typically fairly easy to fix these problems with a little know-how.

Roof valleys are channels designed to drain runoff water, and like any other part of your roof, they can degrade over time with exposure to the elements. In other cases, water can become trapped under shingles which have been overlaid to create the valley trough.

In either situation, the leaking roof valley can be fixed by removing affected shingles and structural elements and upgrading your roof’s flashing. A flashing is a transitional roofing material that connects the roof material to some other building material or to another part of the roof. And flashing is behind most roof leaks.

Repair a Shingle Roof Valley Leak in 6 Easy Steps by All Roofing Solutions

Repair a Shingle Roof Valley Leak in 6 Easy Steps

Prepare For The Repair

Follow these three preparatory steps to get ready to fix the valley leak:

  1. Clear any debris in the roof valley and surrounding area.
  2. Take measurements of your roof flashing – most flashing is 14 inches wide, but yours may vary .
  3. Move to the highest end of the valley and work your way down, cleaning shingles from both sides of the valley whether they’re damaged or not. Experts recommend that you give yourself 8 to 10 inches of clearance on each side of the valley. Use a nail bar to loosen the shingles in the affected area –  insert the bar under a shingle and pry upward at a the location of each nail to loosen a nail. Pull out the nails with the bar.

Repair Damaged Roof Valley

Here’s how to install new flashing in your roof valleys:

  1. Begin by placing the replacement piece of flashing in the valley lining up the groove in the center with the middle of the valley. Make sure the flashing’s bottom edge is perfectly aligned with your roof’s lower edge. Valley flashing comes in standard lengths, ranging from 8 to 12 feet – if your valley is longer, install the lower piece of flashing first then overlap the lower edge of the next piece by a foot.
  2. Use a metal cutter to alter the length of the flashing to ensure it lines up with your roof’s lower edges. At the top edge of your roof valley, check to make sure the flashing is properly angled to line up with the slope of the roof. Use roofing nails to secure the flashing in place, driving nails at 1-foot  intervals along the outer edges of each side from top to bottom.
  3. Replace all shingles you removed, making sure their edges are at least 1 inch from the elevated center of the flashing piece. Work your way up, starting at the lower edge of the roofing and moving towards the top.
  4. Attach the shingles by nailing the upper edges with the appropriate 1 1/2-inch roofing nails for composition or 5d shingle nails for wood shingles. Trim and install rows of shingles that align with the existing rows at each side of the valley.

Don’t put off repairing a leak, as this can lead to additional structural problems, mold growth and high levels of moisture and humidity, all of which can be difficult and expensive to repair.

Hire Professional Roofer For Help

Repairing a roof leak takes experience, and is especially difficult on steep and tile roofs. If you encounter problems, be sure to consult a reliable roofing professional. We can handle these types of repairs quickly and easily, no matter what caused the leak in a first place.

Call All Roofing Solutions, your full service roofing contractor with over 15 years of experience in roofing and re-roofing. We will work with you to identify the damage and present you with options tailored specifically to your situation. Our priority is always to provide you with great service!

Call us at 302-725-7663 in Delaware or 610-551-7663 in Pennsylvania to schedule your FREE estimate. And don’t forget to ask about our discount of 15% off any roofing repair project!




  1. Posted October 19, 2017 at 11:33 pm | Permalink

    I couldn’t agree more that is important not to put off doing these kinds of roof repair, as the article says. Small, seemingly insignificant roof problems can quickly turn into very serious, and expensive, problems. It’s important to remember that the roof isn’t the only thing at risk, since it protects everything beneath it.

  2. Posted October 20, 2017 at 7:46 pm | Permalink

    Repairing a roof via do-it-yourself techniques can only yield so much good. My wife made fun of me for even trying, but I got at least some progress done. In the end, I am going to follow your advice and call a professional for help, as it’s just too much on my own.

  3. Posted October 30, 2017 at 1:40 pm | Permalink

    I don’t get on my roof a lot, so I had no idea my shingles were leaking until I went into the attic after it had rained. They’re only leaking along a trough by the dormer, so it shouldn’t be too hard to repair. I don’t have a lot of time, though, so I might call a professional to save myself the effort.

  4. Posted October 30, 2017 at 8:38 pm | Permalink

    Really glad you had step by step tasks in the description! Knowing how how to repair leak roofs is good to know. What has blown me away is “top to bottom” I didn’t know that is the way it had to happen. Thanks!

  5. Posted November 8, 2017 at 8:03 am | Permalink

    I think in case of roofing, it is better to avoid DIY as it is a complex task, require lots of technical knowledge and extreme caution must be observed because it is potentially a dangerous task, a fall could even lead to loss of life. So instead invest some time in doing research and find the best roofer for your job.

  6. Posted November 12, 2017 at 7:05 pm | Permalink

    Thanks for the tips! I know a little bit about repairing leaks in a shingle roof from helping my dad try to fix leaks when I was a kid. He had some good pointers, but it seems like I should learn a few tips and tricks from another source. Your tips about installing new flashing to my roof will be very helpful. I’ve always had trouble with installing new flashing, especially when it comes to knowing how to properly line them up. I didn’t know that I had to align the flashing with my roof’s lower edge. Now I can be sure that my flashing will be properly aligned.

  7. Posted November 15, 2017 at 8:54 pm | Permalink

    Thanks for mentioning all of the additional problems that can be caused by not fixing a leak when you have the chance. I’ve had a leak for a while now but I haven’t thought much of it. I’d checked around the roof myself and nothing really stuck out to me, but it sounds like I should probably have a pro come look at it for me.

  8. Posted November 28, 2017 at 3:49 pm | Permalink

    Wow, this makes roof repair sound so easy! A huge storm just passed through my area, and it did some damage to the roof. It’s not terrible, but I want to fix it before it gets too terribly bad. It’s good to know that I will want to clear off a pretty large area, so ensure that all the damage is repaired.

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