When a substrate slope will not permit efficient drainage, Elevate ISOGARD Tapered Insulation provides an effective and economical solution. Properly installed ISOGARD Tapered Insulation can extend the life of the roof assembly by eliminating problems associated with ponded water. ISOGARD Tapered Insulation is available in slopes from 1/16″ to 1/2″ per foot and is offered in both our ISOGARD GL and ISOGARD CG product families.