Roof Leaks Near a Gable's Base

Finding the Source

• Locating the exact source of a roof leak, including on the gable ends of the house, can require dedication and detective work. Water may run along surfaces inside the attic before dripping into your living space below, so once you go into the attic to investigate you must follow the trail of water or water damage. If you cannot tell where exactly in the gable the leak is located, you may need to recreate the leak by spraying the gable with a hose while someone watches from inside the attic for leaking water.

House Wrap Problems

• House wrap is a watertight material that sits below the house’s siding or other exterior material, creating a seal against the elements. The improper application of house wrap can lead to water finding its way under the wrap, allowing it to then soak through the wood below and enter the house. In the case of gables, some installers may skip applying the house wrap since they don't think it's necessary for an attic space. In reality, the absence of house wrap may be the only source of a leak, and if so you must have house wrap applied after removing the siding.

Vent Seal Leaks

• The gable vent provides ventilation for the attic, allowing fresh air to flow into the space and helping prevent humidity buildup and mold growth. The vent openings have slats that are angled downward, keeping rain that falls straight down from the roof or sky from entering the attic. If the seal between the vent and the gable fails, water may leak through. Strip away the bad seal before applying a thick amount of silicone caulk around the edges of the vent housing on the exterior of the house, creating a watertight seal.

Blown Rain

• With high winds, rain may come at the gable vents from the side instead of above, allowing some of the water to leak into the attic through the vent despite the slats’ positions. You can create your own baffle to the inside of the attic at the vent opening, made of plywood and triangle blocks. The plywood should be held at an angle over the vent opening to block water from entering the attic, while permitting air to flow normally. Blown rain can also force the water under the house’s siding, causing leaks if no wrap is present.