Type of roof sheathing

Can anyone tell the type of roof sheathing by reading this label?


Your picture is blurry…however it is probably a 15/32 CDX (exterior grade with plenty of knots). The 4 ply itself is deceptive…plywood never have an even number of plys or layers per se…on 4th ply is actually the middle two layers running the same direction. While some code officials will call it out (usually incorrectly) you want to look at are the span ratings (APA) guidelines are met. There should be a stamp with that info on it…usually on the underside.


Buck, Jeff is right about the plies of the plywood.

Plywood is constructed by gluing together a number of layers (plies) of wood with the grain direction turned at right angles in each successive layer. This design feature makes plywood highly resistant to splitting.

An odd number (3, 5, 7) of plies is used so that they will be balanced on either side of a center core and so that the grain of the outside layers runs in the same direction.
The outer plies are called faces or face and back.
The next layers under these are called crossbands, and the other inside layer or layers are called the core.
A plywood panel made of three layers would consist of two faces and a core.

The stamps are placed on the back and sometimes on the edges of each sheet of plywood.

The stamp shown in your pic appears to be a bar code item product similar to Home Depot or Lowes Home center would use, and only identifies the product manufacturer and plies as manufactured for them at a lower cost.

One day late and one ply short as they say. :mrgreen::slight_smile:


Thank for the diagram Marcel…I have my construction book from a 2 year course I took back in the late 70’s…we had to know what all those stamps stood for on various lumber products…somethings have still stayed with me after all those years…my instructor (God rest his soul) would be proud of me…I actually paid attention in class as opossed to most of the guys that were drinking moonshine and smoking weed in class (yes in class…but that was the 70’s wasn’t it).



That it was Jeffery, good ole times. :):wink:

15/32, which is thinner than 1/2", can so be only 4 plys. Just like it says. :stuck_out_tongue: The middles plys are parallel to each other and run perpendicular to the outers. On two ft centers makes a cr#$py roof.