What is Roof Sheathing? When to Replace it? 10 FAQs Answered

Many people see shingles on their roofs and think that’s all there is. However, there is much more beneath the upper surface, and that’s where sheathing comes in. Roof sheathing, or roof decking, is the frame of the roof system upon which shingles are installed.

Vancouver is a tricky place for roofing, with abundant rainfall of 47-63 inches per year. Therefore, you might need to replace your roof sheathing if it’s damaged beyond repair. Understanding the indicators for replacing roof sheathing is crucial in maintaining a secure and weather-resistant roof.

Having an experienced roofing contractor Vancouver also goes a long way in ensuring your roof stays safe and in great condition. Let’s answer some of the most important questions about roof sheathing asked by Metro Vancouver residents.

Frequently Asked Questions (FAQs) 

Q. What is roof sheathing? 

Roof sheathing is the wooden boards, sheets, or planks on which the shingles are attached to protect your roof. Just like a house’s foundation, sheathing is your roof system’s overall foundation.

It plays a crucial role in constructing a well-built roof, ensuring structural integrity and even weight distribution. Roof sheathing installation is necessary to create a functional and secure roof.

Q. What are the benefits of roof sheathing? 

Roof sheathing is an important component of modern roofs in Metro Vancouver and brings many benefits.

• It strengthens the roof structure, enhancing its load-bearing capacity. This protective layer also acts as a barrier against water infiltration, preventing damage to the underlying roof components.
• Roof sheathing aids in distributing the weight of the roof evenly, reducing stress on individual rafters.
• It offers stability and resistance to wind forces, safeguarding the overall structure.

Q. What is roof sheathing made of? 

Roof sheathing is typically composed of various materials. Standard options include plywood, oriented strand board (OSB), composite panels, and paper fibre. Plywood is thin layers of wood veneer glued together.

OSB is constructed from wood strands, compressed and bonded with resin, providing a cost-effective alternative. Composite panels combine materials like foam insulation sandwiched between wood layers for improved insulation properties.

Paper fibre is made from 100% waste paper and is primarily used for commercial buildings, but it can also be used for residential applications. It’s crucial to consult with an experienced roofing contractor in Metro Vancouver to understand how it works.

These materials are chosen based on their strength, moisture resistance, and suitability for the specific sheathing regulations in Metro Vancouver.

Q. How long does roof sheathing last?

The longevity of roof sheathing relies on various factors, including the chosen material, environmental conditions, and upkeep practices. Adequately maintained roof sheathing can typically endure for approximately 20 to 30 years. Timely inspections conducted by the best roofing company and immediate repairs can significantly prolong its lifespan.

It is essential to recognize that different materials, such as plywood or oriented strand board (OSB), may exhibit varying durability and distinct lifespans. Engaging an experienced roofing contractor to evaluate the condition of your roof sheathing is advised. They will provide expert guidance on appropriate maintenance measures or the need for replacement, if necessary.

Q. Is sheathing waterproof? 

While materials like plywood and OSB have some natural resistance to moisture, they are not entirely waterproof. Since Vancouver has an average of 173 rainy days per year, you need to enhance the waterproofing properties of your roof through underlayment or a waterproof membrane.

These layers provide an added barrier against water infiltration, ensuring better protection for the underlying roof components and reducing the risk of water damage. To ensure adequate layers of water protection in your roof sheathing, consult with a credible roofing contractor in Metro Vancouver.

Q. What is the function of sheathing? 

The primary function of roof sheathing is to provide structural support and stability. It acts as a base layer for the roof covering materials, such as shingles or tiles, providing a well-primed surface for their installation.

Sheathing also helps evenly distribute the roof’s weight across the rafters, preventing concentrated stress points. Additionally, sheathing acts as a barrier against moisture, wind, and other external elements, contributing to the overall protection and longevity of the roof system.

Q. How to know when you need new roof sheathing?

Determining when you need new roof sheathing requires a careful assessment.

• Firstly, extensive water damage caused by leaks or prolonged exposure to moisture can lead to rotting or warping of the sheathing, compromising its structural integrity.
• Secondly, if the sheathing is severely cracked, split, or damaged, it may no longer provide adequate support for the roof system.
• If sheathing has encountered pest infestation, it may require replacement to eliminate the risk of further damage.
• Lastly, if the sheathing is outdated or does not meet the Vancouver building codes, you may need to replace it to ensure a safe and compliant roof structure.

If you observe excessive wear and tear, such as splitting or warping, it’s advisable to consult a professional roofing contractor for a thorough evaluation. They can accurately assess the condition of the sheathing and recommend replacement if necessary.

Q. What goes under roof sheathing? 

Before installing roof sheathing, specific components are typically placed underneath. One common layer is roofing underlayment, which provides an additional barrier against water infiltration. Underlayment is usually made of asphalt-saturated felt or synthetic materials.

It is applied directly over the roof deck or insulation and is a secondary defence against moisture. Additionally, an ice and water shield may be installed along the vulnerable areas in regions prone to ice dams to provide extra protection. Talk to your roofing contractor to understand what kind of protective layers they use under the sheathing.

Q. What is plywood roof sheathing?

Plywood roof sheathing refers to thin layers of wood veneer bonded together, offering strength and durability to the roof structure. It is typically installed over the rafters or roof trusses and provides an even surface for the attachment of roofing materials.

The dimensional stability of plywood and resistance to moisture makes it a popular choice in roof construction, ensuring reliable support and protection for the roof system.

Q. How to choose a reliable roofing company?

Although everyone does their due diligence differently, there are still a few important things to know when choosing the best roofing company.

• The roofing contractor should be trustworthy, and you can find out about it by visiting their website and checking third-party reviews.
• Make sure they have WorkSafeBC coverage, so you’re not liable if an injury occurs during work.
• They should also have liability insurance of at least $1 million if the building is flooded or burnt in an accident.
• They should have at least five years of experience in this field and conduct regular inspections during the work and after it’s finished.

Conclusion

Roof sheathing can be extremely beneficial for the stability, longevity, and reliability of your roof. To receive all benefits of roof sheathing, always ensure that these are made of high-quality materials and installed by experienced roofing contractors in Metro Vancouver.