What Is a Peak Cap on a Metal Roof?

The Basics

• A peak cap is a triangular metal panel that fits over the peak of a roof, where the two slopes come together. Peak caps are almost always metallic, whether intended for asphalt or metal roofing. In most cases, you would install the peak cap only after all other shingles or panels have been placed on the roof surface. In other words, it acts as the final piece of the puzzle.

Descriptions

• Peak caps are sold in individual pieces that you can place along the peak of your roof as needed. For example, a structure with a roof 70 feet in length would need more pieces than one with a roof 55 feet in length. A standard piece is 10 feet 6 inches in length, intended to cover 10 feet of roof peak with 6 inches of overlap for the next piece.

Purpose

• Metal roof coverings consist of overlapping sheets or panels that make up the slopes on each side. The overlap between the panels protects the attic and home interior from rain, wind, pests and extreme temperatures, but the peak of the roof -- where the slopes come together -- has no overlap, and this can leave the interior vulnerable to all forms of penetration. The peak cap covers this gap and prevents the elements from entering the home through the top of the roof.

Ridge Vent Caps

• Some peak caps serve only to cover the peak of a roof, but some actually provide ventilation for the attic. A ridge vent, or ridge cap vent, is a specific type of peak cap that contains baffles for blocking out rain and dust while enabling increased air ventilation through your attic. This can improve the efficiency of your home and prevent dangerous moisture accumulation. In some cases it can even negate the need for traditional roof vents altogether.