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I'm looking at hooking up some rain barrels using PVC piping. Is there a certain type of PVC that would be best to use for this, considering that it will be exposed to sun/rain/heat/cold? Lots of people seem to use "regular" white PVC but I didn't think that was intended for outdoor use.

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  • May be of some help vinidex.com.au/files//technical_notes/technical_notes/…
    – UNECS
    Commented Sep 24, 2012 at 2:44
  • The kind that is painted. Commented Jan 11, 2017 at 22:48
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    This is not helpful to the original poster, but may help other searchers. There's something called "furniture PVC" that is highly UV-resistant and suitable for outdoor use. It's only for non-plumbing uses; it's intended for building things like furniture or garden fences or whatever. It's hard to find in stores, but you can buy it online. It's significantly more expensive than normal schedule 40 PVC, but it looks much nicer. This wouldn't have been useful for the original poster, but might be useful for others searching for answers to "Which type of PVC for exposed outdoor use?" Commented Apr 28, 2019 at 5:02

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All PVC is subject to UV light degradation. PVC without UV protection will eventually suffer a loss of impact resistance. Your pipe will be whole, until impact at which it will shatter or crack instead of flex.

Some PVC (PVC UVR) is UV resistant. The sunlight still damages the PVC pipe, but it is in a matrix of other chemicals that compete for the UV light (stealing it away from the would be damaged PVC). PVC UVR will degrade, but at a slower rate.

Thicker wall pipe will take longer to fail, as the UV will be caught by upper layers before penetrating lower layers. Painted pipe will not fail, provided that your paint blocks or reflects UV light (and nearly all paints do).

You are right, a lot of people use PVC pipe, but mostly it is meant to be used in buried applications (where it will be shielded from UV light); however, most of those buried applications come out of the ground at some point. Typically the out-of-ground portions are not properly protected, which is just a timer for eventual failure.

Sometimes that's due to ignorance, sometimes people rationalize that PVC is so cheap the pipe repair in the future will be cheap too. Save yourself the headache of doing it twice, paint your PVC.

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    Great additional explanation on why painting PVC is so important. I didn't realize I should be so distrustful of UV-resistant PVC, or that painting was such a simple fix. Commented Sep 24, 2012 at 14:04
  • To be fair, I think the slower rate will have you covered for a much longer time, but the fix is so easy, why not?
    – Edwin Buck
    Commented Sep 24, 2012 at 14:14
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You could try the gray colored Schedule 80 PVC pipe. This is a much heavier duty material that will stand up to being outdoors. It is recommended by manufacturers. such as U.S. Plastic Corp, that PVC pipe and fittings be painted after installation with a coat of white water based latex paint to provide for UV resistance. The UV light is what is part of the sunlight that can degrade PVC.

Link to manufacturer PVC Pipe Catalog: http://www.usplastic.com/catalog/item.aspx?itemid=23979&clickid=redirect

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