UV Protection For PVC Pipe

[lark55]

When the air conditioning company installed my new unit last year they ran the drain for the water condensate in white pvc pipe. This particular pipe was run across the roof and down to ground level. My concern is that within a few short years the pipe will become so brittle from UV exposure it will break. I am thinking that I could just paint it but am open to ideas.

[sweetolbob]

Sunlight (UV Radiation) won't do it any good long term. Takes a while to diminish the properties but it will degrade with time. Paint it a light color or wrap it with plastic but be aware the plastic covering will also degrade with time.

Newer PVC pipe has a very hard surface due to low levels of formulation so you might need a primer or at least the surface should be roughened. Google is your friend here.

[Studebakercenteroforegon]

UV inhibitors for plastics are not necessarily pigmented so your pipe could very well be UV protected. Back in my injection molding days, our company had a product line of high density polyethylene berry flats - for use between the berry fields and the processing plants. They were usually stored outside when it wasn't berry picking season, so they needed the UV protection. You couldn't tell by looking at them, but they had UV inhibitors without question.

[sweetolbob]

I don't remember if N.M. uses ABS or PVC for their standard DVW pipe but if you drive around past the old homes and you see white pipe sticking out of the roofs then you'll get a idea of how stable PVC is in the sun, which is very stable. The downside is over "MANY" years the UV will degrade the surface and if one was to put pressure on the outside of the pipe, like pulling it, it could crack. PVC fails in a brittle fashion and is notch sensitive when there are surface defects.

Your installation will probably outlast most of us on the forum but for belt and suspenders here, paint will add to longevity.

Polyethylene is a very different animal. It's a member of the polyolefin polymer family which are very susceptible to UV degradation. That's why you find those polymers when used outdoors, loaded with pigments and UV stabilizers. The sun will kill them in short order, otherwise. If you are old enough, recall the first polypropylene web chairs. After one season they weren't safe to set it. Stabilization has come a long way but PE will probably never approach PVC for UV stability.

PVC is a carbon/chlorine based polymer which is darn UV stable to start with and the high level addition of fillers to the pipe formulation adds even better performance in the outdoors. PVC pipe has very little formulation of any kind, just enough to extrude it so it retains maximum rigidity.

Got windy but just recalling a lot of memories of time spent developing and extruding these materials.

[lark55]

I don't know if the UV rays are more intense here because of the elevation (3700 feet) or what, but typically three years is about the most before the pipe is significantly degraded. I will probably just paint it. I am not too keen on working on top of the roof because of stiff knees.

[hausdok]

I can sympathize with the knees.

Doc says mine need replacement. Can't afford to take the time off to do 'em now; but in the work I do as a home inspector I'm up and down stairs over and over and up on the roof and in crawlspaces all the time, so I'm damned if I do replace them and damned if I don't.

Down in NM you're AC system will probably have a service life of no more than 10 to 15 years from installation because you folks down that way use them more than we do up here in the northwest. Ask yourself whether, if the PVC is left unmolested for the expected service life of that AC unit, will it will fall apart or will it probably last as long as the unit will. All it's doing is conveying condensate to grade or a receptor: it's not like it's going to need much strength or rigidity to do that. However, if by "significantly degraded" you mean the stuff is literally coming apart after three years, your idea - painting it - will work fine. Over the years I've seen where hundreds of folks have painted those portions that are exposed outside of the PVC direct-vent exhaust vents for furnaces and water heaters, PVC TPR discharge pipes, PVC AC condensate drains and PVC plumbing vents. All seemed to be fine. I remember one furnace exhaust that had been painted flat black to make it blend in with the shingles. Whatever paint had been used to coat the pipe was flaking off but the pipe itself was great.

I'd test a little bit of exterior-grade acrylic paint on it to see if they're compatible. Pick up a 1/2-inch elbow at the orange box or pull it out of your garage's junk drawer, paint it and toss it outside for a few days where it will be in the bright sun and then check it to ensure the paint isn't flaking off or checking and the pipe hasn't gotten tacky. If it turns out to work fine with the paint, go for it. If it doesn't work, try another type of paint - latex maybe - until you find something that seems to bond well without harming the pipe.

[Bob Bryant]

The development in which I live has about 110 cedar lamp posts. The bases deteriorate over time and I am wondering if a dull black PVC pipe could be used as a post which would last longer and not rot? I will check the ID of the base of the metal fixture on top and determine the diameter needed for a start. It seems like it could be cost effective. We pay about $90 for a post that is prepared for the wiring, etc. Then we have the costs for the electrician to do the replacement.

[wittsend]

I have PVC pipe that carries standard water pressure (50 PSI). There are portions in the yard that have been in So. Cal. sunlight for nearly 20 years, occasionally get yanked on, and are still sound. Being that you are using it on a "no pressure" drain I'd say let your great grand kids worry about it.

Regarding the lamp posts. There may be code requirements for metal. At the least I think they would require the gray electrical PVC. I've never seen electrical in black. Might it be ABS you are thinking of?

[Bob Bryant]

wittsend: Thanks for your response. I was just attempting to identify a black (not glossy) plastic pipe that could possibly used in place of the cedar posts currently being used. A disassembled lamp light is not available at the moment, but the ID of the lamp base appears to be 2 3/4" and the unit rests on a plastic adapter which is then mounted on top of the 3 3/4" square post. Esthetics are important as any change has to please 95 homeowners! The conductor would feed up the inside of the post with a photoelectric cell and an outlet at the base. There is a GFI box on the exterior of the home for the circuit. I am just trying to determine if it is a possible alternative. Checking distributors will help provide an answer. HVAC's and water heaters are starting to fail, also and the committee is looking for ways to cut costs.

[Mikado282]

I had a yard light on a metal pole at my house I just sold that was there 30 years ago when I bought it. It looked to be 15-20 years old at the time so it is almost or about 50 years old. Painted it twice and it will probably last another 50. I know they make fiberglass and composite tubes also although not certain of the cost. Sounds like you have a job akin to herding cats trying to please everybody in a HOA.

[sweetolbob]

wittsend: Thanks for your response. I was just attempting to identify a black (not glossy) plastic pipe that could possibly used in place of the cedar posts currently being used. A disassembled lamp light is not available at the moment, but the ID of the lamp base appears to be 2 3/4" and the unit rests on a plastic adapter which is then mounted on top of the 3 3/4" square post. Esthetics are important as any change has to please 95 homeowners! The conductor would feed up the inside of the post with a photoelectric cell and an outlet at the base. There is a GFI box on the exterior of the home for the circuit. I am just trying to determine if it is a possible alternative. Checking distributors will help provide an answer. HVAC's and water heaters are starting to fail, also and the committee is looking for ways to cut costs.

Bob

Before you start planning a replacement for the existing poles, ask a local electrician/electrical contractor what is allowed by code. You may be quite limited in your choices but it could save legal fees in the future.

Bob

[Bob Bryant]

Bob Before you start planning a replacement for the existing poles, ask a local electrician/electrical contractor what is allowed by code. You may be quite limited in your choices but it could save legal fees in the future. Bob

Bob: I appreciate your thoughts. In CT everything is highly regulated and we use licensed and bonded electricians for even simple tasks. I'll check to see if code enforcement will allow such a change. In a few days I will be north of you fishing out of Sebewaing on Lake Huron. My cell phone will be turned off!

Mikado282 was correct on the herding cats comparison to keeping the HOA folks happy. Monday, we will present our info and recommendations on the change to LED'S at BOD meeting.

[sweetolbob]

Bob: In a few days I will be north of you fishing out of Sebewaing on Lake Huron.

Actually Saginaw Bay but it is a physical part of Lake Huron. I'll assume you will be Walleye fishing along the Henderson and North Island channel and up to the Charity Islands. Some of the best eating fresh water fish to catch grilled. I believe you mentioned you had a family member in Michigan so enjoy. Sometime if you are in the area at a later date we might meet for lunch. Currently, my wife just had surgery so good luck on your trip. Bob

P.S. As an addendum, In case you are going for the first time, take a chest of ice with you and throw the fish into it after you catch them. Helps maintain the nice mild taste.

[Bob Bryant]

Bob: Thanks for the tips on the fishing expedition which I will pass on. My son is experienced on fishing Lake Erie and Michigan, but he is just starting on Huron. When he grew up in Niles we fished Michigan, frequently. He now lives in Deckerville and his work is further north. Every time he visits me he raids my tackle box with my permission. He says he is ready to supply me with needed equipment! If he wants to work hard he can put out eleven lines trolling. I usually pilot the boat and let him and his buddy do the work! This exchange is why I enjoy Stove Huggers! After Memorial Day I hope to visit the SNM again while I am in N. IN.

It is hoped your wife makes a quick and complete recovery. It would be a pleasure to meet you sometime after your wife recovers.

[lark55]

It's interesting and humorous to find this post going from a PVC coating in the desert to fishing for walleyes in the Great Lakes. We do have walleyes in a reservoir about 70 miles north of me but not many people know how to fish for them. I think I'll head up to the mountains of eastern Arizona and fish for trout in about a week.