Vent stack PVC painting

[sfusselman]

Question about painting plumbing vent stacks at roof top. Down here in Texas all PVC vent pipes are painted to protect the PVC from getting brittle from UV rays. I have always had this thought but wanted to see what everyone else thought about it.

If we paint PVC to protect it from the sun then why every home I go to that has pool equipment (PVC lines) do not have their lines painted to protect them.

Thanks in advance for any thoughts.

[Mark P]

I though they just painted them to match the roof color or at least so they do not stand out as much. I've never seen an unpainted PVC stack with any form of deterioration.

[Scottpat]

PVC will degrade over time when exposed to direct sunlight. Very few AHJ's require painting of exposed PVC...

In my area many of the HOA's are the ones that require visible PVC vent pipes to be painted to match the roof color, they want it for looks and not protection. It takes a very very longtime for Schedule 40 PVC to breakdown to he point it becomes brittle.

[inspector57]

On a related note, painting the plastic flashing around the PVC or metal pipe WILL help protect it from UV rays and rapid deterioration.

I roughly estimate a doubling of the life when painted. Here in the sunny southwest the plastic flashing begins to fail in as little as 7 years but I rarely see painted ones that have failed. I tell my clients painting them is like sunscreen and the little light comes on.