GAF has enhanced its Timberline HDZ shingles with the addition of proprietary time-release algae-fighting technology offering homeowners more comprehensive protection for their roof. The time-release product is now standard on many of the shingles offered in GAF’s residential product line, including ridge cap and visible starter strip shingles. GAF Time-Release Algae-Fighting Technology is comprised of specially engineered capsules that release copper steadily over time. Compared to more traditional copper-coated granules that can eventually degrade and become less effective, GAF’s capsules are infused throughout with thousands of copper microsites for long-lasting algae- fighting power. GAF offers a 25-year StainGuard Plus Algae Protection Limited Warranty against blue-green algae discoloration on many of the company’s most popular products.