Anti Hot Spot Tape - Is a purposely designed foam tape that is adhered to your framework, prior to polythene fitment, in areas where the polythene will come into direct contact with frame materials. It provides a protective barrier between the frame and the polythene sheet. This prevents damage due to agressive contact or heat damage. It is a proven means of prolonging the life of your polythene.
If you are using horticultural polythene for any greenhouse application, whatever the frame material (steel, aluminium, plastic or timber) you should seriously consider the use of a non-PVC anti hot spot tape.