What is Roof Decking? (Types, Replacement Timing, and More)

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Your roof is one of the most important parts of your home, protecting you from weather and outside elements. A roof isn’t just the shingles you see; it has several layers that work together to keep your home safe and watertight. One of the key parts of your roof system is the roof decking.

Roof decking, or roof sheathing, serves as the base of the roof where we attach roofing layers. In short, roof decking is the backbone of your roof. In this article, we will go through the various types of decking, when you should replace it, and more.

Types of Roof Decking Material

Plank decking and sheet decking are the two main types of roof decking. Each type has its benefits and best uses, depending on your roof’s structure and your home’s needs.

1. Plank Decking

Plank decking was the standard material for roofs before sheet decking was introduced. The planks are usually 1x6 or 1x8 boards, placed side by side across the roof’s trusses. We often see plank decking in older homes because contractors used it before plywood and OSB gained popularity. The downside is that it creates small gaps between the boards, making it hard for shingles to lay flat.

2. Sheet Decking

Sheet decking, or sheathing, is the most common type of roof decking used in homes today. Made of large, flat sheets of wood, it creates a more even surface than plank decking. Two main types of sheet decking exist:

  • OSB (Oriented Strand Board): OSB is the most popular type of sheet decking. It consists of compressed wood chips and adhesives that form a solid sheet, usually 7/16 inches thick. OSB is affordable, durable, and provides a smooth, even surface for shingles and other roofing materials.
  • Plywood: Plywood is another common material for sheet decking. It comes in various thicknesses, like 3/8, 1/2, 5/8, and 3/4 inches. Plywood consists of many layers of thin sheets of wood that create a strong, stable surface. While homeowners may prefer plywood for its durability and performance, OSB tends to be more popular and cost effective.

Both OSB and plywood are Guy Roofing’s recommended choices for roof decking. The choice between them often comes down to budget, availability, and personal preference. When your decking is in need of replacement, our team will discuss your options with you so you can make an informed decision.

When should you replace roof decking?

Knowing when to replace roof decking is important for maintaining a strong, durable roof. Here are some signs that it may be time to replace your roof decking:

Visible Rot or Decay:

If your roof decking shows signs of rot or decay, it’s time for a replacement. Rot weakens the wood and can compromise the strength of your roof, leading to leaks or even a collapse.

Sagging Roof:

A sagging roof often means that the decking underneath is no longer strong enough to support the weight of the roof. Water damage, age, or poor installation could cause this, and you should have it inspected right away to prevent more damage.

Water Damage or Stains:

Water stains on the ceiling or walls may mean water is leaking through the roof and can damage the decking. If left untreated, water damage can cause the wood to soften and weaken, eventually leading to structural problems.

Mold and Mildew:

Mold or mildew growth on the roof decking shows there is a moisture problem that should be inspected. Mold not only damages the wood but can also cause health issues. Replacing the damaged decking and addressing the moisture source can help prevent mold in the future.

Roof Replacement:

Often, roof decking is inspected and partially replaced when you get a new roof. If the decking remains in good shape, you do not need to replace it. However, Guy Roofing will replace any rotten or weak parts that we find to create a strong base for the new shingles.

The Cost of Replacing Roof Decking

Roof decking cost varies depending on the type of decking, the extent of the damage, and the current price of wood. Here’s a general idea of what to expect:

Plank Decking:

Plank decking is usually more expensive than sheet decking because it’s sold by the linear foot. The cost increases if many individual planks need replacement. Covering old plank decking with a layer of OSB or plywood is often cheaper.

Sheet Decking (OSB or Plywood):

Sheet decking is typically priced per sheet and is less expensive than plank decking. OSB is generally cheaper than plywood, making it a popular choice for budget-conscious homeowners. However, the size of your roof and the amount of decking that needs replacement determine the total cost.

Maintaining Roof Decking

Regular maintenance can help extend the life of your roof decking and keep your roof in good shape. Here are some tips for keeping your roof decking in top condition:

Regular Inspections:

Have Guy Roofing inspect your roof at least once a year to check for signs of damage or wear. Our team of experts will catch issues early, which can prevent roof leaks and costly repairs later.

Keep Gutters Clean:

Clogged gutters can cause water to back up and seep under the shingles, which can damage the roof decking. Regular gutter cleaning can help prevent water-related problems. Guy Roofing will work with you to create a custom water management system to protect your home and roof decking.

Ensure Proper Ventilation:

Bad ventilation can cause moisture to build up in the attic. This can lead to mold and mildew on the roof decking, causing a bigger issue. Good ventilation helps prevent moisture damage and extends the life of your roof.

Address Leaks Immediately:

If you notice any leaks or water stains on your ceiling, have Guy Roofing inspect and repair them right away. Leaks can quickly damage roof decking and weaken the overall roof, leading to costly repairs if not addressed.

By following these steps, you can help ensure that your roof decking stays strong and durable, supporting your roof and keeping your home safe.

Understanding the Importance of Roof Decking

Roof decking plays an important role in the structure and safety of your roof. It provides a strong base for shingles, keeps out moisture, and supports your entire roofing system. Understanding the types of roof decking, signs of damage, and the need for regular maintenance can help you make better choices for your home.

At Guy Roofing, we’re here to help you with all your roofing needs, and help you make informed decisions. If you need a roof inspection, replacement, or repairs, our roofing experts are here to help. We will ensure your roof decking and entire roof system are in great condition.

For more information or to schedule a free in-home consultation, call Guy Roofing at 800-771-0778. You can also schedule an appointment online by selecting a time that works best for you. Let us help you keep your home protected with a strong, quality roof.

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