Roof Valley Repair in Marietta, GA
A roof valley is the V-shaped channel where two slopes meet. Every drop of water that hits either slope above the valley funnels through it. Which means valleys see roughly five times as much water as the rest of the roof. They're the first thing to wear out, the first thing to leak, and the most common cause of the kind of slow attic leaks that turn into ceiling stains months after the actual problem started.
We repair and re-build valleys across Marietta, GA and Cobb County. Most valley repairs are a single-day job and dramatically extend the life of an otherwise solid roof.
The Three Valley Styles and How Each Fails
Open metal valley
A pre-formed metal channel runs down the V with shingles cut back on either side, leaving the metal exposed in the middle. Most durable style, easiest to clear of debris, longest-lasting. Failure mode: the metal rusts through (especially older galvanized) or the sealed edges fail at the shingle interface.
Closed-cut valley
One slope's shingles run all the way through the valley. The other slope's shingles get trimmed back along a chalk line. Most common style on Cobb County asphalt roofs. Failure mode: the cut line wears through the shingles below it, especially on the high-water side.
Woven valley
Both slopes' shingles weave across the valley with no cut. Older style, less common today. Failure mode: shingle wear on both slopes simultaneously, debris collects in the weave and traps moisture.
Why Valleys Fail Even When the Rest of the Roof Looks Fine
Volume of water plus debris. Pine straw, oak tassels, and small branches collect in the valley. They hold water against the shingles long after a rain ends. The shingles in that strip wear out three to four times faster than shingles elsewhere on the roof. By year 12 to 15 of a 25-year roof, the valleys are often shot even though the field shingles have years left.
The other reason: missing or insufficient ice-and-water shield underneath. The valley should have a self-adhered membrane lining the entire V from edge to edge. Many older roofs only have felt under the valley, which doesn't seal nail penetrations and leaks at every fastener.
How We Repair a Failing Valley
Strip back to the deck
Pull shingles back roughly two feet on each side of the centerline. Remove the old valley underlayment.
Install ice-and-water membrane
Self-adhered membrane the full length of the valley, lapped properly with the underlayment above and below.
Install new metal valley flashing or re-shingle as closed-cut
Depending on the original style and your preference. We typically convert older closed-cut valleys to open metal during repair because metal lasts longer and resists debris wear.
Weave shingles back into the field
New shingles tie into the existing courses with proper offset and nailing. Color match where possible.
What Valley Repair Costs in Cobb County
Single valley repair runs $600 to $1,800 depending on length, valley style, and shingle work needed to tie back in. Multiple valleys or full re-flash on a complex roof runs $2,000 to $5,000. Decking replacement (if water has rotted the sheathing under the valley) adds material cost.
When to Repair a Valley vs. Live With It
If your roof has 5+ years of life left and the valley is the only problem area, repair the valley. If your roof is approaching end of life and the valleys are just one of several problems, full replacement may be the better dollar value.
Get a Free Valley Inspection
Call (678) 720-3565 or use the contact form. Free inspection with photos. Most valley repairs scheduled within a week.