OSB. T1-11 siding comes in two major grades, plywood and OSB (or oriented stand board). Plywood T1-11, also known simply as plywood siding, can be stained if you’re looking for a natural wood look, or it can be primed and painted as well.Click to see full answer. Accordingly, what is t1 11 siding made of?T1-11 is a type of siding made of plywood, meaning it’s a material made from thin sheets of wood veneer. These are glued together to give you the look you see. It also means that this is an engineered type of wood.Secondly, what does t1 11 mean? Plywood and other compressed wood siding products are an inexpensive way to sheath outdoor buildings, sheds and other projects. T1-11, sometimes noted as T111 or T1, is an example of one of many such wood siding products. The ‘T’ in T1 stands for “textured,” which references the grooves or channels cut into the siding. Beside above, what plywood is used for siding? Plywood Sheathing. When considering plywood for sheathing, builders choose from 1/2-inch CDX — common construction-grade material — or 1/2-inch pressure-treated plywood. Both of these materials cost more than 7/16-inch OSB does, which also works as a suitable exterior sheathing material.Is t1 11 siding treated?T1-11 siding features narrow, evenly spaced grooves on a rough-finished board for a pastoral appearance. Pressure treated for above ground applications, T1-11 siding features grooves spaced either 4″ or 8″ on-center to provide options for achieving the look you desire for your home, shed or pump house.