What Are Roof Planks? A Complete Guide to Roof Planking

Introduction

Roof planks, sometimes called roof decking or sheathing, are an essential part of any roof structure. But what exactly are roof planks and what purpose do they serve?

This comprehensive guide will explain everything you need to know about roof planking materials, installation best practices, and safety considerations when working on a roof.

What are Roof Planks?

Roof planks refer to the sheets or boards installed across roof rafters or trusses to create the roof deck. This decking provides the surface that roofing materials like asphalt shingles, metal roofing, or tile will be installed on top of.

The main purpose of roof planks is to provide a sturdy, level base for the roofing material. The planks transfer the weight and forces from the roofing down through the framing and to the exterior walls.

The planks also create a solid sheathing over the roof framing, providing critical bracing and rigidity to the overall roof structure.

Properly installed roof planking is essential for protecting against leaks, insulating the attic space, and securing the roofing against wind uplift forces.

Different Materials Used for Roof Planks

There are several options when it comes to selecting material for roof planks:

Plywood

Plywood is the most common material used for roof sheathing. It is made from thin sheets of wood veneer glued and pressed together at right angles. The cross-lamination of the wood grain provides strength and rigidity.

Plywood is affordable, readily available at most hardware stores, and easy to cut and install. It withstands weathering well and resists rotting. Plywood thickness for roof decks is typically 5/8″ or 3/4″.

OSB (Oriented Strand Board)

OSB has become a popular alternative to plywood. It is manufactured from small wood chips and strands arranged in layers then bonded together with adhesives. The wood strands are oriented for strength.

OSB roof sheathing is cheaper than plywood and just as structurally sound. However, it doesn’t handle moisture absorption quite as well as plywood and can be more difficult to work with when cutting.

Wood Boards

Using dimensional lumber boards, typically 1×6 inch, for roof planking provides a traditional appearance. Wood boards allow you to match other trims and architectural details on the home. Cedar and redwood boards have natural rot resistance.

The downside is that durability and longevity depends heavily on the wood species used. Proper spacing is crucial to allow for drying and prevent warping or cupping.

Metal Decking

For some commercial roofing applications, corrugated metal decking is used instead of wood sheathing. The metal sheets are lightweight yet very strong. Metal allows for longer spans between roof framing.

Disadvantages include the noise created during rain or hail. Metal decking requires experienced installation to properly interconnect the sheets.

Plank Thickness and Spacing

Installing Roof Planking Correctly

Safety Considerations When Planking a Roof

Working on a roof can be dangerous. Take these roof planking safety precautions:

Conclusions

Installing proper roof planking or sheathing is a critical step when building or replacing a roof. Understanding the best materials, correct installation techniques, and safety procedures will ensure your roof decking lasts for decades without issues.

Always check your local building codes and have a professional roofer address any questions or concerns about your roof planking project.

FAQ’s