What is the minimum thickness of plywood for a roof?
Most Common Thickness. For rafters spaced 20 or more inches apart, 1/2- or 5/8-inch plywood is recommended. The most common rafter spacing is 24 inches, and 5/8-inch plywood is recommended for that. It will support roof loads for most situations and is the standard for most roof applications.
Standard Thicknesses. Before lumber companies began selling OSB, the standard choice for sheathing a roof with a 24-inch rafter spacing was 1/2-inch CDX plywood - the letters CDX indicate that it is construction-grade material intended for exterior applications.
- In roofing terminology, sheathing plywood is the layer of material attached to the structural frame of the roof. After you frame the rafters and ridge board, you lay the sheathing on top to cover the entire frame. The tar paper and composite shingles (or other roofing material) go on top of the sheathing plywood.
- SMARTPLY OSB3 is a strong, versatile board suitable for structural use in humid conditions (service Class 1 and 2), ideal for applications as diverse as roofing, flooring, hoarding and wall sheathing etc..
- Particle board – also known as particleboard, low-density fibreboard (LDF), and chipboard – is an engineered wood product manufactured from wood chips, sawmill shavings, or even sawdust, and a synthetic resin or other suitable binder, which is pressed and extruded.
Roof and Floor. If you want the shed to be waterproof, its roof must be constructed just like any other roof -- a plywood decking covered with shingles or with composite or metal roofing. Most builders use 15/32 CDX for the roof; it is an exterior-grade plywood with a thickness just under 1/2 inch.
- Most Common Thickness. For rafters spaced 20 or more inches apart, 1/2- or 5/8-inch plywood is recommended. The most common rafter spacing is 24 inches, and 5/8-inch plywood is recommended for that. It will support roof loads for most situations and is the standard for most roof applications.
- OSB takes longer to get wet than plywood but also takes longer to dry out. When used as a roof sheathing, this tendency to hold moisture means it can degrade faster than plywood when exposed to chronic leaks.
- Use these two tables for roof rafters with a slope of 3" in 12" or less.
Nominal Size Spacing (o.c.) Species and Grade of Lumber ( 20# Live Load - No Finished Ceiling) 2" x 8" 16 19-6 24 16-8 2" x 10" 12 27-6 16 24-8
Wood fiber is used more efficiently in osb. Osb is stronger than plywood in shear. Shear values, through its thickness, are about 2 times greater than plywood.This is one of the reasons osb is used for webs of wooden I-joists. However, nail-holding ability controls performance in shear wall applications.
- Plywood is a broad category of sheet good building materials. It is often extended beyond traditional wooden plywood to include medium density fiberboard (MDF), particleboard, hardboard and chipboard. ACX is a designation given to a traditional wood exterior plywood panel with one sanded face and one rough face.
- BCX plywood has a handsome, well-sanded face and a less-finished back side. It typically contains C-grade inner layers and is bonded with exterior glue. BCX comes in a variety of thicknesses and can be made from soft or hard wood.
- Oracle Service Bus, aka OSB, is an Enterprise Service Bus implementation by Oracle. OSB, formerly known as AquaLogic Service Bus, was acquired when Oracle bought BEA Systems. Oracle Service Bus transforms architectures by connecting, mediating, and managing interactions between services and applications.
Updated: 21st November 2019