Gases that escape from the PVC (polyvinyl chloride) pipes contribute to the deterioration of the polyethylene plastic. To prevent "off-gasing," paint the PVC pipes with white latex paint.

Interesting about the paint..I have not read that but it makes sense. Also it is true my contractors grade 6 MIL lasted only 1 summer and it was about $75 for a roll. Still have some left so i guess I can use it for something around here.

So if you painted the PVC and then you used a quality grade UV plastic such as green house grade plastic I wonder would that trick "increase" the life span so instead of 2-3 years you could get 4-5 years maybe? .........Just a thought