The PVC pond liner from Gordon Low is ideal for small to medium sized ponds and has excellent flexibility and a high puncture resistance. This is cut from a 4 metre wide roll of PVC pond liner so simply choose how many metre you require and we will cut this to size x the 4m length. Gordon Low PVC Pond Liner 0.5mm thick, 4m wide and sold per running metre off the roll. Lining Tips. For the liners maximum length, measure the longest maximum length across the pond, add to this TWICE the maximum pond depth, then add another 2 feet minimum or 60cm. For the liners maximum width, simply do this the other way so measure the maximum width of the pond, add to this TWICE the maximum pond depth, the add another 2ft or 60cm.