Overview

A shingle valley is one of the most detail-sensitive areas on any roof. Water concentrates in valleys and flows at high volume in a Florida rainstorm — a valley that is not installed correctly will leak. The California closed-cut valley is the Trust Roofing standard for shingle valleys. It provides superior waterproofing, a clean finished appearance, and excellent performance in Florida's high-rainfall conditions.

Our Field Standards

Shingle valley installation follows Trust Roofing field standards for closed-cut technique.

Field standards include:
* Valley metal or peel-and-stick is in place before any shingles are installed in the valley area
* The first side of the valley runs shingles past the center line by at least 12 inches
* The second side cuts back to a straight chalk line at least 2 inches from the valley center
* The cut edge of second-side shingles is sealed with roofing cement on the underside
* No nail is driven within 6 inches of the valley center line
* The cut is made with a hook blade

Our Process

Preparing the Valley

* Confirm valley metal or peel-and-stick underlayment is installed and photographed
* Snap a reference chalk line along the center of the valley
* Plan which side will be installed first — typically the less visible side

Installing the First Side

1. Run shingles from the first side, extending past the center line by at least 12 inches
2. Clip the upper corner of each shingle at 45 degrees as you pass over the center
3. Do not nail within 6 inches of the valley center on this side

Installing the Second Side

1. Run shingles from the second side, extending past the center line
2. Snap a chalk line parallel to the valley center, at least 2 inches from it
3. Cut the second-side shingles back to this line using a hook blade
4. Apply roofing cement to the underside of the cut edge before pressing down
5. Do not nail within 6 inches of the valley center

Final Inspection

* Run a hand along the cut edge — it should be tight and sealed
* Check that the valley channel is clear and unobstructed
* Confirm no nails are visible within 6 inches of the valley centerline

Roofing Terms

California Closed-Cut Valley

A shingle valley installation method where shingles from one side extend fully across the valley and the second-side shingles are cut back on a clean chalk line, the Trust Roofing standard for shingle valleys in Florida.

Hook Blade

A curved cutting blade preferred for cutting shingles in a valley, reduces the risk of cutting through the underlayment below while producing a clean, straight cut along the chalk line.

Valley Channel

The open area at the center of a shingle valley through which water flows, must be clear and unobstructed after installation, with no nails driven within 6 inches of the valley centerline.

Florida Rainfall Intensity

Tampa Bay receives some of the heaviest annual rainfall in the United States, valley installation quality is critical because valley failures during Florida storms are one of the most common sources of significant interior water damage.

Roofing Cement

An asphalt-based sealant applied to the underside of the cut edge of second-side valley shingles, seals the trimmed edge against water infiltration and wind uplift at the most water-concentrated area of the roof.

Related Topics