Interesting Optical Effect with PVC drain pipe

Visible infrared?

Jonh

White PVC sticking out the roof? 4"? Wow. White PVC usually becomes rotten from UV pretty quickly. If it isn't painted it begins to turn brown within 2-3 years in our area. After some more years you can sometimes crumble it by hand.

Same here. Generally all above-ground stuff around here is done in ABS (or metallic pipe).

...Jim Thompson

That's how our vents are done (and not 4"). Probably a code requirement, or at least it should be, just like the code prescribes protruding lengths so the vents aren't plugged by a snow pack.

Read the above again, the part sticking through the roof is covered in lead flashing as is standard practice.

AS usual the topic veers far away from the question asked :{

Up to the top in lead? Wow, haven't seen that yet. I wouldn't do that either though because it'll get hot.

But yes, PVC can "glow" if it isn't very thick.

if it's loaded with TiO it'll last several decades exposed.

Contractors typically use the cheapest stuff they can get. Made in China.

Around here, it takes considerably less time than that. The pipes I ran to my pools solar heater were quite dark within a year, even the ones by the pumphouse that are mostly in the shade!

Charlie

Duh. They're light pipes.

I'd put something over the top of them to keep birds from putting their nests there and plugging them.

Good Luck! Rich

Would it make any difference if they were black ABS? It would obviously dramatically minimize the "glow", but how's black ABS's UV susceptibillity vs. white PVC?

Thanks, Rich

Wouldn't that be TiO2?

Thanks, Rich

So, how is Chinese PVC different from "domestic" PVC (if there is any such thing any more)? I'd have assumed that PVC is PVC.

Thanks, Rich

Is there anything over the top of the hole, like a shroud? If not, then it's pretty obvious, like those SS skylights.

Thanks, Rich

...

That's because the question is so stupid.

What the hell is "visible infrared?"

Thanks, Rich

AFAIK there is stuff mixed in to provide UV stabilization and so on. We have some 10ft lengths of very old PVC pipe, plus elbows and whatnot in the garage from the previous owner of the house. Wherever I used some of that it took forever to blacken or never blackend. Sometimes you end up with two tees in a row, same location. After 2-3 years one is brownish-black, the other almost as white as new. Guess which one is the new tee?

Nah, there's virgin and there's regrind, and recycled plastic crap (in varying percentages of each). There's LOTs of different additives, to improve extrudability, placticizer to make it flexible, heat stabilizers, UV stabilizers, fire retardants, etc.. Some years ago Taiwan makers were making window blinds from extruded PVC with a lot of UV stabilizer (as you might expect)-- only problem was that it was lead, and the blinds slowly disintegrated under sunlight, yielding lead-bearing dust. There's also potential health problems with some fire retardants, which have been banned already in Europe and maybe in North America too by now. Some of the smelly flexible PVC (like swimming pool liner smell) is as much as 30% plasticizer chemicals.

But most PVC pipe, IME, is made domestically because it's cheaper to turn the silos full of powder into bulky hollow tubing close to the point of use, and requires virtually no labor (automated take-off equipment, automated saws and stacking, and then straight onto the flatbed).

The vent pipes sticking out the roof on our house are like that. Deterioration over >35 years: None.