New World Mfg Inc?

In concrete tanks 30 mil pvc is recommended since it is far less permeable than 20 mil pvc but either material can be used. Hypalon will be recommended if any of the following conditions exist: * if the tank has an open top and the liner is exposed to ultraviolet light;permanent roof support posts * if the size of the tank or reservoir dictates that the liner be made and installed in more than one panel; * if the concrete is heavily cracked; * if there are permanent, non-moveable support posts; * if there are concrete dividers, with or without penetrations or openings; * if there are any unusual penetrations through the floor, interior dividers or exterior tank wall. a geo-textile underlayment material should always be used to protect the liner if the inside of the tank is cracked or rough. after installation has been completed, seal the exposed geo-textile at the top of the tank with a bead of silicone around the entire circumference. If this step isn't performed, condensation will form on the tank walls and seep out through the geo-textile.