What Are the Effects of Sunlight on PVC?



sunlight-pvc-pipe-effectsYou wouldn't believe some of the crazy things people are making out of PVC these days. We are always amused at new creative uses for it, and sometimes that leads to unexpected questions about using PVC pipe and fittings.

Whether you find yourself using PVC for recreation or for plumbing and industrial handling, you may need to know how using PVC outdoors will effect the material. Here's your answer!

PVC PipeĀ Strength

PVC is known and used around the world for its amazing rigidity and strength. Many times users are fearful of using PVC outdoors for fear of losing some of those strength properties. Is this a legitimate fear, though? The quick and easy answer is, no, not really.

PVC does surprisingly well when exposed to ultra violet rays (sunlight). Research shows little to no effect on PVC's tensile strength or elasticity after prolonged sun exposure. The only degradation that seems to occur is impact strength. That means the pipe may become slightly more brittle after prolonged sun exposure.

PVC Sunburn? - UV Exposure

So what does the sun do to PVC pipe? In some cases it causes it to discolor. That means the normally white PVC will start to turn a brownish color. This is only true of untreated PVC after prolonged UV exposure.

There are some types of PVC pipe and fittings that are treated to protect against UV rays (furniture grade PVC for example). All the color change means is that the very outer layer of the pipe is altered, affecting the pigment.

How should you protect your outdoor pipe?

Manufacturers suggest a thin coat of a latex based paint to protect pipe from discoloration and any other adverse effects that may occur. Choose a white or light colored paint and cover any areas that will be outdoors. This will shield that outer layer of plastic and keep your pipes functioning well for years.