Prevent Mortar from Making Contact with Insulation. Professionals know a properly functioning drainage system is the prerequisite for a masonry design to achieve maximum thermal efficiencies while reducing maintenance and repair costs. With the CavClear Insulation System, the mortar obstructions and droppings which impede drainage are completely prevented when installed full height. The CavClear Insulation System features the CavClear® Masonry Mat factory bonded to rigid insulation. The Masonry Mat will not allow mortar to make contact with the insulation. If your goal is to provide a continuous drainage area behind brick or stone in an insulated masonry wall, look no further than the CavClear Insulation System.