There are many different components to a roofing system. While most homeowners are familiar with the shingles and gutters, they may not be as familiar with other aspects of a roof including the flashing, underlayment, or sheathing (also known as decking).

In this article, we will focus on roof sheathing/roof decking. Roof sheathing is a sturdy layer of wood boards that are fixed to the joists and trusses of the roof. The shingles are attached to these wood boards.

What does roof sheathing do?

The primary purpose of roof sheathing is to provide a support system and additional strength for your roof. Sheathing supports the shingles, provides protection against weather elements, and evenly distributes the weight of the roof.

What is roof sheathing made of?

Roof sheathing is usually made from plywood or oriented strand board (OSB). While both materials are wood, they each have their own pros and cons. Plywood is more durable, but this durability comes with a higher price tag. It also is a heavier material. OSB is usually preferred by roofers due to the fact this it is lightweight and is less expensive. OSB might not be the best option if you are using heavier roofing material like concrete or slate roofing tiles.

Other less common roof sheathing materials include wood boards or concrete sheathing. Roof sheathing thickness is usually 5/8” inch thick.

What are the benefits of roof sheathing?

There are a number of key benefits provided by roof sheathing. These benefits include the following:

It helps provide support and strengthens your roof

The weight of shingles can be significant for a roofing structure. Roof sheathing provides the support needed to ensure there isn’t any sagging or bowing of the roof. This helps ensure that the weight is evenly distributed across the roof. This is especially important in cases where there may be heavy amounts of snow or precipitation.

It helps protect against leaks

Roof sheathing provides an additional layer of protection against weather elements, especially if the decking is weatherproof. This increases the lifespan of your roof and protects against water damage.

It helps protect against fires

Roof sheathing or decking can also protect your home from fires. Many of the roof sheathing materials are fire-resistant. This helps prevent fire ignition and it slows the spread of a fire to other parts of the home.

How can you tell when you need new roof sheathing?

Since roof sheathing is such an important part of your roofing system you will want to make sure it is not worn out or damaged. While roof sheathing is usually replaced during the re-roofing process, there are other indicators that may alert you that your sheathing needs to be replaced. Here are four signs to watch out for:

  1. The sheathing is broken – if you can see the broken sheathing boards or if the roof is starting to sag this is a clear sign the sheathing needs to be replaced. This may be the result of too much weight being placed on one area of the roof. For example, if something falls and lands on the roof (like a tree branch). The weight of the object can break the sheathing boards.
  2. A sagging ceiling or roofline – if you see sagging along your roofline or if you see sagging with your ceiling you should call a professional. Both of these problems may indicate a need for new roof sheathing.
  3. Water damage or rot – if you see water stains or leaks on your ceiling, you will need to do further analysis to find the source of the problem. Water damage to sheathing can be especially problematic because it can impact the structure of your roof. Water damage can lead to a number of problems including rotting with the sheathing. If you see darkened spots on the wood it likely means rotting is taking place. If you suspect a leak here is some information on how to find the leak.
  4. Holes of light in the roof – if you see light passing through holes in your roof, you will need to call a roofing professional. Any holes in the roofing system can allow water through the roof and cause long-term problems.

The professionals at Modern Blu are here to help with any roof or sheathing problems you may have. If you live in the Flower Mound, Lewisville or greater Dallas area and suspect you may have a leak call our professionals at Modern Blu at 469-546-7636, or contact us online to schedule an appointment. We would be happy to provide a free roof inspection!