Exterior PVC Expansion and Contraction

[AGinVT]

So we made the switch from MDO to exterior PVC a while back and wondering what tricks everyone uses to keep their 1/2" and 3/4" PVC signs from flexing as temperatures change. My shop is in Vermont, so the temps can vary quite a bit from Summer to Winter. We have been channeling out little horizontal Mike and Ike-shaped holes for our hardware to allow for size fluctuations with varying success. Wondering what everyone else does to control the expansion and contraction of exterior PVC?

 

[unclebun]

We don't use PVC outside. Even if they say you can. As you have found, it's unstable with temperature changes, and even in thick panels it warps.

 

[AGinVT]

We don't use PVC outside. Even if they say you can. As you have found, it's unstable with temperature changes, and even in thick panels it warps.

So do you stick with aluminum composites, sign foams and MDO for exterior? Do you have a go to for rigid signage? ACM always needs to be framed in. Need something simple and economical for my clients for bracketed and hanging signs.

 

[unclebun]

Most signs we use ACP (Aluminum Composite Panel). We don't find it necessary to always frame it. If rigidity of a blade is needed, we use the 6mm thick ACP. For hanging signs we use either MDO or straight aluminum as they are better at holding the fasteners. But we stay away from hanging signs if at all possible because of the problems with wind flapping them around.

 

[Asuma01]

ACM "always" needs to be framed in? News to me.

 

[John Miller]

Avoid dark colored exterior PVC signs, they will absorb the sun's heat and turn into a pretzel. I've had success with white PVC signs @ 1" thick. Another drawback that will come into play in Vermont is that PVC becomes brittle in very cold weather, especially after a few years.

 

[FireSprint.com]

We sell a ton of 6mm PVC for exterior use. We find that the brand and grade can matter greatly. We stock 6mm Sintra specifically for this reason. Other grades don't seem to perform as well.

PVC Products, Rigid Full Color, Auto Plates, Counter Cards

PVC Products include auto plates, rigid full color PVC signs, security signs and counter cards. Digitally printed in full color.

www.firesprint.com

Don't get Sintra confused with the Sintra Vers (That's the new name for ePVC and is cheaper.)

Graphic Display Products

Moderately expanded PVC with a premium bright white or black satin finish, engineered for high performance.

3acompositesusa.com

 

[brdesign]

somewhere on the Sintra website there are technical documents that gives advise on the mounting, and formulas to calculate the thermal expansion and contraction of Expanded Foam PVC sheets. The mounting hole should be at least 2.5 times larger than the diameter of the screw/bolt and use a large washer. The mounting screw and washer should not be too tight, it should be just snug to allow the pvc to move. For a rectangular sign an oval shaped hole would be ideal since there will be more movement on the longer dimension. I think something like a 3/16" x 7/16" oval mounting hole is recommended for a 48" x 96" sheet