What Is Roof Decking: A Homeowner’s Guide

by | Jan 6, 2023 | Blog | 0 comments

As a homeowner, you might not spend a ton of time thinking about the structural components of your roof. That’s alright. Roofing contractors, like us, think about it for you!

The fact of the matter is that your roof is a complex system designed to keep you and your home protected from the elements. That system includes:

  • Roofing materials, like shingles and shakes
  • Ridge vents
  • Flashing
  • Insulation

And, of course, we can’t forget the roof decking.

As the foundation of your roof, having a well-installed roof deck can be the key between a safe home and one that is prone to leaks and water damage. But what is roof decking? Read on to learn everything you need to know.


Roof decking functions a lot like the foundation of your home. It offers support to your roof and helps it maintain its structural integrity.

Roof decking comes in a variety of materials and is layered on top of your roof’s insulation before other roofing materials are attached. This provides an important protective layer for the interior of your home. Damaged roof decking can lead to water damage to the walls and ceiling of your attic space or mold and mildew growth in your insulation.


Now that you understand what roof decking is, it is important to understand the options you have when it comes to roof decking materials.


Got a historic home? It’s possible you are still dealing with plank sheathing decking material.

Plank decking material was the go-to choice for many years. These days, a roofing contractor knows better.

Made from rows of long wooden boards, this type of roof decking was once popular due to its stability and ability to hold lots of weight. However, any professional roofer will now tell you that this style of roof decking is known for needing roof repairs, as they are prone to cracking and breakage.

If you’re looking to update your roofing system, we recommend starting by choosing a different roof decking material.


plywood roof decking with felt underlayment

Sheet decking, also simply referred to as plywood decking, is the most common type of roof sheathing used these days. Plywood is relatively affordable with excellent durability. It is also fairly resistant to moisture, making it a great choice if you live in a damp climate.


Metal decking is not often used in residential buildings but is quite popular for commercial properties!

When it comes to durability, you simply cannot beat metal sheathing. It stands up well to all sorts of extreme weather conditions, such as rain, hail, and snow, making it suitable for almost all climates. Adding metal decking during your roof replacement can help you save on energy costs, as well, as it is a great insulator.

That being said, if you are replacing your entire roof system with metal sheeting, you will be looking at a significantly higher cost than you would find with either sheet of plank decking.


Not sure whether it’s time to replace your roof deck or if you should wait for a while? Here are some signs that it is time to schedule your roof decking replacement.

1.) Leaking Roof

If you have been noticing roof leaks, it’s important that you contact a roofing professional ASAP. Leaks are a sure sign that your roof deck has been damaged and can lead to bigger, more expensive problems down the road if not dealt with promptly.

2.) Rotten Decking

Doing some routine roof repairs and notice that a part of your roof feels spongy? It’s time to invest in a new roof. A spongy roof is a telltale sign that your decking is in need of speedy replacement.

rotten roof decking

3.) Uneven Roof

If you are struggling with things such as ice dams or pooling water, it may be that your roof deck was improperly installed. Without an even roof, you will have trouble getting proper drainage and might be facing some serious water damage problems.


So, you’re ready to start the roof replacement process. But how much should you budget for?

In general, homeowners who are replacing roof decking can expect to spend anywhere between $7000-$12,000 on a new roof deck. This number will change depending on the size of your home and the type of roofing materials that you choose to purchase.


Ready to get started? When it comes to installing new roof decking, you can count on the team at MARS Restoration to take care of your home. Contact us today to set up your free roof inspection and get started.