Multiple use concrete form liner

Claim 1

In combination with large smooth surfaced panels for concrete forms for structural members, a multiple use liner comprising a sheet of soft, flexible, resilient, elastomeric synthetic polymer material which is inert to concrete and having a generally smooth rear surface in face contact with said large smooth surfaced panels, said sheet being formed independently of said panels and supported thereby; the opposite face of said liner having a concrete contacting face formed as a negative mold including undercuts of a desired pattern on the set concrete; said sheeting being at least about 3/8 inch thick at its thinnest section; said sheet having a hardness of from .Badd..[.10-80.]..Baddend. .Iadd.35-70 .Iaddend.Shore A, which permits said material to be deformed without damage for releasing from the designs in the set concrete and having an elongation of from 100-1,000 percent at a tensile modulus of from 150-2,000 psi at 100 percent elongation, a .[.tensile.]. .Iadd.tear .Iaddend.strength in excess of 20 pounds per .Iadd.square .Iaddend.inch, whereby said liner may be removed from a design in set concrete without damage to the concrete including undercuts in the design and said liner squeezes against an adjacent liner under the weight of contained concrete to seal the joint line therebetween and seal around ties or the like passing through the liner.