Does PVC Board warp inside a building?

If its being mounted directly to the exterior curtain wall, I think they might warp at that size.

I'd use ACM, throughbolt it, and leave about a 1/4" bigger hole for the bolt to account for expansion on the metal ribs.

*edit
And then sell him an exterior wall sign to cover up the nuts on the outside

 

FYI...
Eglin Air Force Base McKinley Climatic Lab is used to test various equipment, aircraft, tires etc has a temperature range from −80 °F (−62 °C) to 140 °F (60 °C).

140° F + pvc = tremendous warpage

 

I would go with the ACM - it comes in a few colors also.

 

If I went PVC, I wouldn't go with less than 1/4" / 6mm

 

3mm? Something that thin, but that large makes me wonder. 3mm (or even 6mm) adds little to the look. Why does it have to be dimensional?

Why not paint it?

 

If its a warehouse it's probably ribbed.

 

Maybe in Florida... in California, we are mostly concrete/tilt up...

Though you can still paint ribbed...

If it is ribbed, don't use 3mm PVC, if ribbed, I would make 3 rails, attach them to the wall, then attach the letters to that.

 

Go with ACM or 12mm PVC.

12mm PVC is an underrated material in smaller sign shops. For larger companies doing retail interior signs, it's one of the most popular materials to use. If cut some "washers" out of the waste material and glue it to the back, you can get very cheap but effective offset look. Obviously location and line of site matters.

 

You do know there is outdoor rated PVC sheet right? Palight comes to mind.

 

Without knowing, Id assume there's just more UV inhibitors in the mix and nothing to make it more resistant to heat?