Ventilation and flashing systems allow a roof to breathe and move water away from critical components such as chimneys, valleys, rake and eave edges. To ensure no racking of shingles and a watertight drainage channel around flashings and flanges, shingles will have to be cut to size on the roof before installation. Watch our crew in action as they custom cut field shingles to fit around a newly installed slant back air exhaust. Whether you have a roofing repair or roofing replacement question, you can call the pros at Cenco Building Services at (720)-583-1690 for honest and straightforward feedback and excellent service. #CencoCares #BestInClass