(Oops, typoed schedule in the subject)

Hello all,
I'm seeing where people are using schedule 40 pvc, typically the white one, outside for garden structures. Granted it's the cheap one but it has a flaw for outside use; it's not UV resistant.

This means that over time the plasticizers will break down/evaporate and your structure now becomes brittle. How long this takes depends on your locations sunlight exposure duration and intensity.

Schedule 80, the gray one, IS UV resistant but it's typically about 7.5 times more in cost; depending on the size; than schedule 40. 😕

There is an out! You can use any outdoor rated paint, lighter colors work better, and paint your schedule 40 pvc pipe to increase its longevity.

[Edit]Given the smoothness of the pvc surface it helps to roughen it up prior to painting. Coarse steel wool, brillo pad, sandpaper, whatever you have handy will work. It'll paint faster, easier, and the paint will adhere better. I'm assuming a brush application.[/Edit]

Being a facilities engineer in the brutally solar Southwest US for 37 years has proven this. Unpainted schedule 40 in the AZ, NV, UT deserts might last 3 years where as painted can last as much as 8.

Hth,
Barrie

I built an enclosed garden structure 15 years ago of PVC (strengthened with metal conduit pipe inside) and covered with chicken wire. I wish I had known about the U/V problem then and the idea of painting the PVC. The whole thing is falling apart now.

I have to rebuild it. But I will paint the PVC this time. And lay down a weed blocker all around the edges to prevent vine growth up the chicken wire!

Yardenman said: I built an enclosed garden structure 15 years ago of PVC (strengthened with metal conduit pipe inside) and covered with chicken wire. I wish I had known about the U/V problem then and the idea of painting the PVC. The whole thing is falling apart now.

I have to rebuild it. But I will paint the PVC this time. And lay down a weed blocker all around the edges to prevent vine growth up the chicken wire!

Hi Yardenman, this is an extra step that I missed in my original post but since pvc is smooth and hard to paint it'll help If you take a brillo pad, steel wool, etc. and roughen up the surface prior to painting. (I'm assuming a brush. Spray paint is SO expensive and eco-unfriendly.)

That's a good tip. I use Sch 40 PVC for mini hoop frames. One problem I have is that the horizontal pieces sag under their own weight over time. Gives the frame the appearance of a sway backed mule. Because I don't glue the parts together, I'm able to just rotate the sagging part to make it look like a camel backed mule. The other problem I have is that the fittings also sag in the sun and makes the whole frame kind of goofy.

Perhaps some seismic wire on the top of the horizontal pieces to hold them up. Home Depot.