Types of Roof Decking

Last updated on September 20, 2023

Discover the various types of roof decking materials in this comprehensive guide, designed to help you make an informed decision for your next roofing project.

Welcome to my blog where I share my knowledge about roofing. Today, we are going to talk about an essential component of any roofing system – the roof decking.

The roof decking is the foundation on which your roof sits, and it plays a critical role in ensuring the stability and durability of your entire roofing system. In this article, we will explore the different types of roof decking available in the market today and their unique features.

Whether you are a homeowner or a professional roofer, this article will provide you with valuable insights into choosing the right type of roof decking for your project. So let’s dive right in!

What Is Roof Decking?

types of roof decking

It is a layer of material that sits on top of the roof trusses or rafters and provides a flat surface for attaching shingles, tiles, or other roofing materials. The primary purpose of roof decking is to provide structural support for your roof while also protecting it from moisture damage.

The type and quality of the roof decking you choose will depend on several factors such as climate conditions, building codes in your area, budget constraints, and personal preferences. Some common types include plywood or OSB sheathing (oriented strand board), tongue-and-groove planks made from wood or composite materials like PVC plastic.

It’s important to note that not all roofs require deckings; some metal roofs can be installed without them because they are self-supporting due to their design features.

Roof Decking serves as an essential component in any roofing system by providing structural support while protecting against moisture damage.

Roof Decking Material

It provides a stable base for the roof covering and helps to distribute the weight of the roof evenly across the structure. There are several types of materials used for roof decking, each with its unique features and benefits.

One popular type of roofing material is tongue-and-groove boards, which are made from solid wood planks that interlock with one another. This type of decking offers excellent strength and durability while also providing a beautiful finish that can enhance your home’s curb appeal.

Another common option for roof decking is plywood or oriented strand board (OSB) sheathing. These materials consist of thin layers or strands bonded together using adhesives to create a strong, flat surface suitable for supporting shingles or other types of roofing materials.

Plank sheathing is another traditional option that has been used in construction since ancient times. Plank decks consist simply in laying wooden planks side by side over rafters spaced at regular intervals apart from each other; this method was commonly employed before modern sheeting became available on large scales.

Tongue and Groove

It consists of interlocking boards with a tongue on one side and a groove on the other, which fit together snugly to create a strong, stable base for your roofing system.

One advantage of using tongue and groove decking is its ability to provide an even surface that can support heavy loads without sagging or warping. This makes it ideal for areas with high snowfall or where there are frequent storms.

Another benefit of this type of decking material is its aesthetic appeal. Tongue and groove boards have an attractive appearance that adds character to any home’s exterior design.

However, it’s important to note that tongue-and-groove installation requires more time than other types because each board must be precisely cut so they fit tightly together without gaps between them. This type may not be suitable in areas prone to moisture damage as water can seep through the seams between the planks causing rotting over time if not properly maintained.

Plywood or OSB Sheathing

Plywood is made from thin layers of wood veneer that are glued together in a cross-grain pattern, while OSB is made by compressing strands of wood with resin and wax.

Both materials have their advantages and disadvantages. Plywood has been used for decades as a reliable roofing material due to its strength, durability, and resistance to moisture.

It also provides excellent insulation properties when compared to other types of sheathing materials.

On the other hand, OSB has become increasingly popular in recent years due to its affordability. It’s less expensive than plywood but still offers good structural support for your roof system.

Ultimately the choice between these two materials will depend on your budget constraints as well as personal preferences regarding performance characteristics such as water resistance or insulation value.

Plank Sheathing

It consists of wooden planks, usually made from pine or cedar, which are laid horizontally across the roof rafters. Plank sheathing provides excellent ventilation and allows air to circulate freely between the roofing material and the attic space.

One advantage of plank sheathing is its durability. When properly installed and maintained, it can last for many years without needing replacement.

However, it requires regular maintenance to prevent rotting or warping due to exposure to moisture.

Another benefit of plank sheathing is its aesthetic appeal. The natural wood grain adds character and charm to any home’s exterior while providing a rustic look that complements various architectural styles.

If you’re considering using plank sheathing as your roof decking material, keep in mind that it may not be suitable for all types of roofing materials such as asphalt shingles because they require solid support underneath them.

Purpose of Roof Decking

The decking serves as the foundation for your entire roofing system, supporting not only the weight of your shingles or tiles but also any additional loads such as snow, ice, or wind.

Without proper roof decking in place, your roof would be vulnerable to damage from weather conditions and other external factors. A sturdy deck ensures that all parts of your roofing system work together seamlessly to protect you and your home from potential hazards.

When it comes time to replace or repair a damaged roof deck, it’s important to choose high-quality materials that can withstand harsh weather conditions while providing long-lasting support for years to come.

Assessing Your Existing Roof Decking

This will help you determine whether or not it needs to be replaced and what type of material would be best suited for your new roof.

One way to assess the condition of your existing roof decking is by inspecting it from inside your attic. Look for signs of water damage, such as stains or mold growth, which could indicate a leak in the roofing system.

You should also check for any sagging areas that may suggest structural issues with the deck.

Another way to evaluate your current roof decking is by examining its age and history. If you have an older home with an original wooden deck, there’s a good chance that some sections may need replacing due to rotting or decay over time.

If you’ve experienced severe weather conditions like hailstorms or hurricanes in recent years that caused significant damage to other parts of your home’s exterior (such as siding), then chances are high that they might have affected the integrity and stability of your current roofing system too!.

Addressing Wooden Deck Problems

However, wooden decks are prone to several problems that can compromise the integrity of your roofing system. Some common issues include rotting, warping, splitting or cracking.

If you notice any signs of damage on your wooden deck such as sagging or leaking roofs, it’s essential to address them promptly before they worsen. Ignoring these problems can lead to more significant issues like water damage and mold growth.

One way to prevent wood rot is by ensuring proper ventilation in the attic space below the deck. This helps regulate temperature and moisture levels which can cause decay over time.

Another solution is treating the wood with preservatives that protect against fungal decay and insect infestation. Regular maintenance such as cleaning gutters regularly also goes a long way in preventing water buildup on your roof decking.

In some cases where there’s extensive damage beyond repair, replacing all or part of your wooden deck may be necessary for safety reasons.

Plank Decking

It consists of wooden planks that are laid perpendicular to the rafters and nailed in place. Plank decking was commonly used in older homes, but it is still an option today for those who want to maintain a historic look or prefer the natural beauty of wood.

One advantage of plank decking is its durability. When properly installed and maintained, plank decks can last for decades without needing replacement.

They also provide excellent ventilation, which helps prevent moisture buildup and reduces the risk of mold growth.

However, there are some downsides to using plank decking as well. One major concern with this type of roofing material is fire resistance – untreated wood can be highly flammable if exposed to heat or flames.

Another issue with plank decks is their tendency to shrink over time due to changes in temperature and humidity levels – this can cause gaps between planks that allow water infiltration into your home’s interior spaces.

Sheet Decking

It consists of large sheets made from materials such as plywood, oriented strand board (OSB), or composite panels. Sheet decking provides a smooth surface for the installation of shingles, tiles, or other roofing materials.

One advantage of sheet decking is its ease and speed of installation compared to plank sheathing. The large sheets can be quickly installed over the roof trusses or rafters with minimal cutting required to fit around vents and other protrusions.

However, it’s important to note that not all sheeting products are created equal when it comes to durability and strength. Some lower quality OSB products may have issues with moisture absorption which can lead to warping over time if not properly protected by underlayment.

When choosing sheeting for your project make sure you select high-quality options like CDX plywood which has been treated against moisture damage or Huber Zip System Sheathing which features an integrated water-resistant barrier on both sides making it ideal for use in areas prone to heavy rainfalls.

When Should Roof Decking Be Replaced?

However, over time, roof decking can deteriorate due to various factors such as moisture damage or age-related wear and tear. So when should you replace your roof decking?

The answer depends on several factors such as the type of material used for your current deck, its age, condition and exposure to harsh weather conditions.

If you notice signs of rotting or decay on your existing deck during a routine inspection or after severe weather events like heavy rainfalls that cause leaks in the attic space below the deck; then it’s time to consider replacing it.

Another sign that indicates replacement is necessary is if there are visible cracks or warping present on wooden decks. These issues can compromise their structural integrity leading to potential safety hazards.

It’s also important to note that some types of roofing materials require specific types of decking materials for optimal performance. For example: metal roofs need solid sheathing while asphalt shingles work well with plywood sheathing.

How Much Does Roof Decking Cost?

The type of material you choose, the size and complexity of your roofing project, and labor costs are some key considerations.

Plywood or OSB sheathing is a popular choice for roof decking due to its affordability. On average, plywood or OSB sheathing can cost between $15-$25 per sheet depending on thickness and quality.

Tongue-and-groove boards tend to be more expensive than plywood or OSB but offer better durability in harsh weather conditions. Plank sheathing is another option that provides excellent strength but at a higher price point compared to other materials.

Labor costs also play an important role in determining how much you will pay for your roof decking installation. The complexity of your roofing project will affect labor costs as well as any additional work required such as removing old shingles or repairing damaged areas before installing new deck materials.

It’s essential to get quotes from multiple contractors before deciding on which one suits your budget best while still providing high-quality workmanship with durable materials that meet code regulations.

The Code Related to Roof Decking

The International Building Code (IBC) sets the standards for roof decking materials and installation methods. It is essential to ensure that your chosen roof decking material meets these requirements.

For example, the IBC requires a minimum thickness of 15/32 inches for plywood or OSB sheathing used as roof decking. Tongue-and-groove boards should have a maximum span of 24 inches between supports.

It’s important to note that local building codes may have additional requirements beyond those set by the IBC. Therefore, it’s crucial always to check with your local building department before starting any roofing project.

Roof Sheathing Materials

They provide a stable base for the roof covering and help to distribute the weight of the roof evenly across its supporting structure. The most common types of roof sheathing materials include plywood, oriented strand board (OSB), plank decking, and concrete.

Plywood is a popular choice for many homeowners due to its strength, durability, and affordability. It is made from thin layers or plies of wood that are glued together in alternating directions to create a strong panel.

OSB is another commonly used material that has gained popularity over recent years due to its cost-effectiveness compared with plywood. OSB panels consist of compressed strands or chips bonded together with resin glue under high pressure.

Plank decking was once widely used as a roofing material but has since been replaced by more modern options such as plywood and OSB. Plank decking consists of solid wood boards laid side by side on top of rafters or trusses.

Concrete roofs have become increasingly popular in recent years due to their durability and resistance against harsh weather conditions such as hurricanes, tornadoes, hailstorms among others.

Comparing OSB and CDX Plywood As a Roof Decking Material

Both materials have their unique features and benefits that make them suitable for different roofing applications.

OSB (Oriented Strand Board) is a type of engineered wood made by compressing strands or flakes of wood with adhesive resins. It is known for its strength, durability, and resistance to moisture.

OSB has become increasingly popular in recent years due to its affordability compared to other types of sheathing materials.

On the other hand, CDX plywood is a traditional option that has been used as roof decking material for decades. It consists of thin layers or plies of wood veneer glued together with an adhesive resin under high pressure.

While both OSB and CDX plywood have similar structural properties such as strength and stiffness, there are some differences between them that may affect your choice when selecting a roofing material:.

  • Moisture Resistance: While both materials can withstand some level of moisture exposure without significant damage if exposed long enough; however, over time they will begin deteriorating at different rates.
  • Cost: In general terms -OSBs tend to be less expensive than plywoods.
  • Appearance: Plywood tends not only look better but also provides more uniformity in thickness across each sheet which makes installation easier

Concrete Roof Deck

It is made of reinforced concrete slabs that are poured on top of steel or wooden frames. Concrete roof decking can withstand heavy loads and extreme weather conditions, making it an ideal option for flat roofs.

One advantage of using concrete as a roofing material is its longevity. A well-maintained concrete roof deck can last up to 50 years or more with minimal repairs needed over time.

The thermal mass properties of the material help regulate temperature fluctuations in your building by absorbing heat during the day and releasing it at night.

However, there are some downsides to consider when choosing a concrete roof deck. The weight of this type of roofing system requires additional structural support from your building’s foundation which may increase construction costs significantly compared to other materials like plywood or OSB sheathing.

Exterior Gypsum Board

It is made from gypsum, which is a naturally occurring mineral, and it offers several advantages over traditional plywood or OSB sheathing.

One of the main benefits of exterior gypsum board as a roof decking material is its fire resistance. Gypsum board has excellent fire-resistant properties and can help prevent the spread of flames in case of an accidental fire.

Another advantage offered by exterior gypsum board as a roofing material is its moisture resistance. Unlike wood-based materials such as plywood or OSB sheathing, which are prone to rotting when exposed to moisture for extended periods, exterior gypsum boards are highly resistant to water damage.

However, it’s important to note that not all types of exterior gypsum boards are suitable for use on roofs. Only those specifically designed for this purpose should be used since they have been tested and certified by relevant authorities like ASTM International (American Society for Testing Materials).

How Often Should Roof Sheathing Be Replaced?

However, like all other parts of your roof, the sheathing will eventually wear out over time due to exposure to harsh weather conditions such as rain, snow or wind. So how often should you replace your roof sheathing?

The answer depends on several factors such as the type of material used for the decking and how well it has been maintained over time. For instance, if you have a wooden deck that has not been adequately protected from moisture or pests like termites or carpenter ants; then chances are high that it may need replacement sooner than later.

In general terms though most experts recommend replacing old roofs every 20-25 years depending on their condition at inspection times.

It’s important to note that regular inspections can help identify potential problems early enough before they become major issues requiring costly repairs down the line. Therefore homeowners should schedule routine maintenance checks with professional roofing contractors who can assess their roofs’ overall health status regularly.

The Cost of Replacing Roof Decking

The cost of replacing roof decking varies depending on several factors such as the type of material used, size and complexity of the project, location, and labor costs. On average, homeowners can expect to pay between $2-$5 per square foot for materials alone.

However, keep in mind that this estimate does not include labor costs or any additional expenses that may arise during installation. Labor costs vary widely depending on where you live and who you hire for the job.

It’s important to note that while opting for cheaper materials may seem like a good way to save money upfront; it could end up costing more in repairs down the line if they fail prematurely due to poor quality or improper installation.

Roof Sheathing Tips– How to Spot Rotted Roof Decking

Over time, exposure to moisture, pests, and other environmental factors can cause your roof decking to rot or deteriorate. If left unchecked, this can lead to significant structural damage that could compromise the safety and integrity of your entire roofing system.

So how do you spot rotted or damaged roof decking? Here are some tips:.

1. Look for signs of water damage: Water stains on ceilings or walls inside your home may indicate a leak in the roofing system caused by damaged sheathing.

2. Check for soft spots: Walk around on top of the roof (if it’s safe) and feel for areas where there is give underfoot; these areas may be weakened due to rotting wood underneath.

3. Inspect from below: In an attic space with access beneath the deck surface look up at it using a flashlight; if light shines through gaps between boards then they have separated due either from shrinkage over time or because they have been exposed too long without proper protection against weather conditions such as rainwater infiltration which causes swelling leading eventually into warping followed by splitting apart along grain lines resulting in cracks running across them horizontally like spider webs!

Understanding Code Regulations

These codes ensure the safety and structural integrity of your roofing system. The International Building Code (IBC) is a set of standards for commercial buildings, while the Residential Building Code (IRC) applies to residential structures.

The code outlines requirements for minimum thicknesses, spans between supports, nailing patterns and other specifications that must be met when installing roof decking materials. It’s essential to understand these regulations before starting any roofing project as non-compliance can lead to costly fines or even worse – an unsafe structure.

It’s also important to note that different regions may have their own unique building codes based on local weather conditions or other factors. Therefore it is crucial always check with your local authorities before beginning any construction work on your property.

Is It Time to Inspect Your Roof Decking?

Over time, the weather elements can take a toll on your roof decking, causing damage that may not be visible from the outside. That’s why regular inspections are necessary to identify any issues before they become major problems.

If you’re experiencing leaks or noticing signs of water damage inside your home or business premises, this could be an indication that there is something wrong with your roof decking. Other signs include sagging roofs and cracked shingles.

It’s recommended to have a professional roofer inspect your roofing system at least once every year for any potential issues with the deck structure. A thorough inspection will help identify any weak spots in the deck structure and determine whether repairs or replacement are necessary.

Regular inspections of your roof decking can save you money by identifying small problems before they turn into significant expenses down the road.

Roofing Components Explained: Roof Penetrations

One of the most important but often overlooked aspects is roof penetrations. These are any openings in your roof, such as vents or chimneys, that allow for air circulation and exhaust.

While these penetrations serve an essential purpose in keeping your home comfortable and safe from harmful gases like carbon monoxide, they can also be a source of leaks if not installed correctly. That’s why it’s crucial to work with an experienced roofer who understands how to properly install and seal these components.

There are several types of roof penetrations you may encounter during a roofing project:.

  • Vents: These come in various shapes and sizes depending on their function (e.g., attic ventilation or plumbing vent). They typically sit on top of the roof deck.
  • Chimneys: A chimney is used for venting smoke from fireplaces or furnaces out through the roof.
  • Skylights: A skylight allows natural light into your home while providing insulation against heat loss.
  • Each type requires specific installation techniques tailored to its unique design features. For example, flashing must be installed around chimneys to prevent water infiltration at this vulnerable point where two different materials meet.

Roofing Components Explained: Roofing Materials

There are various types of roofing materials available in the market today. Each material has its unique features that make it suitable for specific applications.

As a homeowner or professional roofer, you need to consider several factors when choosing the right type of roofing material for your project. These include durability, cost-effectiveness, energy efficiency and aesthetic appeal.

Some popular types of Roofing Materials include asphalt shingles which come in different colors and styles; metal roofs which offer excellent durability; clay tiles that provide an elegant look to any home; slate roofs known for their longevity among others.

It is essential to choose high-quality materials that can withstand harsh weather conditions while still maintaining their structural integrity over time.

Solid Sheathing

It is typically made from plywood or oriented strand board (OSB) and comes in various thicknesses depending on the specific application.

One of the main advantages of solid sheathing is its ability to provide excellent support for heavy roofing materials such as slate or tile. This type of decking also helps prevent moisture from penetrating through gaps between boards, which can lead to leaks and other water damage issues.

When installing solid sheathing, it’s important to ensure that all joints are properly sealed with an appropriate sealant. This will help prevent any potential water infiltration into your home’s interior spaces.

Open Sheathing

It consists of horizontal boards or planks spaced apart to allow air circulation between them. This design allows the roof to breathe, which helps prevent moisture buildup and rotting.

One advantage of open sheathing is its ability to reduce heat buildup in the attic during hot weather. The gaps between the boards allow hot air to escape, keeping your home cooler and reducing energy costs.

However, there are also some disadvantages associated with open sheathing. One major drawback is that it can be more susceptible to wind damage than other types of roofing materials because it lacks solid support underneath.

If you’re considering using open sheathing for your next roofing project, make sure you consult with a professional roofer who can help determine if this option will work well for your specific needs and climate conditions.

Understanding different types of roof decking materials available in today’s market will help you make an informed decision when choosing one suitable for your project requirements while ensuring durability and longevity over time.


What are the different types of roof decking?

Answer: The different types of roof decking include orientated strand board, plywood, and concrete.

What is the best type of roof decking?

Answer: The best type of roof decking is Ipe wood decking, as it is considered the gold standard for long-lasting, high-performance, and real wood decking.

What is the difference between roof sheathing and decking?

The difference between roof sheathing and decking is that there is no difference, as both terms refer to the flat wood boards that form the base of a roof, which are secured across the trusses and joists of a home.

What is a roof deck called?

A roof deck is called sheathing, which serves as the foundation of the roofing system, connecting the roof to the house and supporting the weight of the roofing shingles.

What factors should be considered when choosing the right type of roof decking?

When choosing the right type of roof decking, consider factors such as materials, durability, climate, weight support, insulation, and cost.

How does the choice of roof decking material impact the overall performance of a roofing system?

The choice of roof decking material significantly impacts the overall performance of a roofing system, as it affects durability, insulation, structural integrity, and resistance to environmental factors.

What are the common installation methods and maintenance requirements for various types of roof decking?

Common installation methods and maintenance requirements for various types of roof decking include using appropriate fasteners, ensuring proper ventilation, regular inspections, and repairing or replacing damaged areas.