3rd Nov 2023 -

Choosing the right subfloor material is a critical decision in any construction or renovation project. Among the myriad options available, plywood sheets stand out as a popular choice. But is plywood always the best one?

In this comprehensive guide, we delve into the fascinating world of subfloor materials, comparing a plywood subfloor with its counterparts to help you make an informed decision. From strength to moisture protection, we will explore the factors that truly matter, ensuring your floors not only stand the test of time but do so with style and resilience.

Is plywood the right choice for your subfloor?

The choice of subfloor material is a vital decision. Delve into the pros and cons of plywood, MDF, fibreboard, OSB, and chipboard to unravel which sheet material aligns best with your goals.

From moisture resistance to versatility, we break down the essentials to empower you with the knowledge to make a confident choice.

Plywood - Flexible plywood has high strength and stability.
 - Good moisture resistance (with exterior plywood).
 - Wide availability and variety of grade options and types.
 - Suitable for heavy loads and high-traffic areas.
 - Can be sanded and refinished.
- Higher cost compared to some alternatives, depending on the chosen veneers. 
 - Heavier than some alternatives.
 - May have visible wood grain patterns.
 - Thickness may vary across veneer plywood sheets.
Medium Density Fibreboard (MDF) - With MDF vs plywood, MDF has a low to moderate cost.
 - Smooth surface for finishing.
 - Consistent density and thickness.
 - Versatile and suitable for subflooring and other various applications.
 - Quick and easy installation.
 - Low moisture resistance, prone to swelling and warping.
 - Not suitable for high-moisture environments.
 - Lower strength vs using plywood or OSB.
 - May not provide the same level of structural support as plywood or OSB.
Oriented Strand Board (OSB) - High strength and dimensional stability.
 - Cost-effective and commonly used as a subfloor material.
 - Resistant to warping and provides a solid base.
 - Easy to install and work with.
 - OSB is likely to not bend or sag.
 - Quick and easy installation.
 - Susceptible to moisture if not properly sealed.
 - Formaldehyde emissions may be a concern in some products.
 - Limited availability of grades compared to plywood.
 - Also limited resistance to long-term exposure to moisture.
 - May not be suitable for heavy loads or high-traffic areas.
Fibreboard - Cost-effective compared to other sheet materials.
 - Uniform density and thickness.
 - Fibreboard is lightweight and easy to handle.
 - Suitable for dry environments.
 - Provides a flat surface for flooring.
 - Limited moisture resistance, not suitable for wet areas.
 - Less durable than plywood and OSB.
 - Not suitable for high-moisture environments.
 - Fibreboard has limited strength for heavy loads.
 - Limited suitability for wet areas.
Chipboard - Chipboard is generally more affordable compared to other subflooring materials.
 - It is often easy to install, which can save time and labour costs.
 - Can be used with various floor types, such as laminate, tiles, carpet, or vinyl.
 - Chipboard is often made from recycled wood materials, making it a more sustainable option.
 - Chipboard is susceptible to damage from moisture, which can cause swelling or warping.
 - May not be as durable as other subflooring materials, potentially requiring replacement sooner.
 - Unsuitable for areas prone to high moisture levels, such as bathrooms. 
- Chipboard can compress under heavy loads, impacting its structural integrity.

OSB vs plywood: what is the best option for you?

Based on the comparison table above, plywood and OSB are the 2 practical choices for building a subfloor. Choosing the right subfloor material is crucial for the stability and longevity of a construction project. Plywood and OSB each have their own set of advantages and considerations.


Plywood is renowned for its high strength, stability, and versatility. It offers good moisture resistance, especially when opting for exterior-grade options such as marine plywood. This makes plywood an excellent choice for subfloors in various applications, including areas with heavy loads or high foot traffic.

Plywood's ability to be sanded and refinished adds to its appeal, providing a durable and long-lasting foundation for finished flooring. Plus, you can achieve insulation in an insulated plywood subfloor by adding a separate insulation layer. Installing rigid foam insulation panels between the joists before laying the plywood can enhance thermal performance.


OSB is cost-effective and a widely used subfloor material known for its high strength and dimensional stability. Resistant to warping, OSB provides a solid base for flooring installations. Its ease of installation and quick turnaround make it a favourite among builders.

However, it is essential to note that OSB may be susceptible to moisture if not properly sealed. The range of available grades is more limited compared to plywood. With insulation, some manufacturers produce OSB panels with integrated insulation. This is often in the form of rigid foam. 

Overall, both plywood and OSB have their merits. Plywood excels in versatility and refinishing options, while OSB stands out for its cost-effectiveness and ease of installation. You should consider factors such as budget, specific requirements, and local weather conditions when making your final decision.

How much does it cost to build a subfloor?

In this cost comparison, we will outline material expenses, labour fees, and additional considerations for both plywood and OSB subfloor installations. It is important to note that these are general estimated costs. 


  • Plywood subfloor: Plywood tends to be a bit more expensive than OSB. For a 2440mm x 1220mm sheet of marine plywood at 18-22mm thick, expect to pay around £25 - £35 per sheet. Additional materials, such as screws, adhesive, and underlayment, will add to the overall cost.
  • OSB subfloor: OSB is generally more cost-effective. A 2440mm x 1220mm sheet of OSB with a thickness of 18-22mm could cost around £15 - £25 per sheet. Similar to plywood, you will need additional materials like screws, adhesives and underlayment.


  • Plywood subfloor: Labour costs can vary widely depending on location and the complexity of the job. On average, you might expect labour costs to range from £10 - £20 per square metre.
  • OSB subfloor: OSB installation is generally simpler. Therefore, labour costs might be slightly lower compared to plywood. You could estimate a similar range of £10 - £18 per square metre.

When considering subfloor options, installation ease plays a pivotal role. Plywood, with its intricate structure, demands careful handling during installation. This can potentially affect labour costs. However, OSB's consistent build often translates to a smoother installation process, possibly saving on labour expenses.

Moisture resistance is another critical factor. Waterproof plywood excels in this department, boasting higher resistance compared to OSB. If moisture poses a concern, additional measures like moisture barriers may be necessary with OSB, which will likely impact the overall cost.

How to prepare for your OSB or plywood subfloor

Below are our essential tips to ensure a solid foundation for your OSB subfloor or flooring with plywood. From levelling uneven surfaces to choosing the right materials, our guide covers crucial steps to achieve a stable subfloor. 

  • Clean and clear: Before laying OSB or plywood panels, ensure the existing subfloor is free from debris. Sweep or vacuum thoroughly to create a smooth surface.
  • Level it out: Check for any uneven areas on the subfloor. Sand down high spots and use a levelling compound for low spots to create a flat surface.
  • Inspect for damage: Examine the existing subfloor for any signs of damage, such as water damage or rot. Remove any damaged sections before installing new OSB or plywood.
  • Secure loose subfloor: If the existing subfloor is squeaky or has loose areas, screw the subfloor down to the floor joists. This ensures a stable and quiet subfloor.
  • Moisture protection: Install a moisture barrier if needed, especially in areas prone to moisture. As a result, this helps prevent issues like warping or mould growth.

Choosing the right thickness for your subfloor

It is important to select the right OSB or plywood with the appropriate thickness. From square-edge OSB, birch, hardwood and fire-rated plywood, discover the key factors that guide the choice of your sheet material thickness. 

Load-bearing capacity

Plywood often provides higher structural integrity per thickness compared to OSB. Evaluate load requirements and explore whether a thinner plywood option can match the strength of a thicker OSB panel.

Grading and thickness

Consider how grading influences thickness requirements. While both plywood and OSB come in various grades, plywood's structural qualities might mean that a thinner panel can meet the same standards as a thicker OSB panel. Learn more about plywood grades with our article.

Joist span

Plywood's inherent strength might allow for thinner panels in cases of wider joist spans. Explore the balance between thickness and performance, especially in areas with extended spacing between joists.

Moisture resistance

Be sure to investigate how OSB or plywood thickness correlates with moisture resistance. Thicker panels of either material may offer enhanced protection against moisture, ensuring a resilient subfloor.

Flooring compatibility

Evaluate the recommended thickness for subfloors based on the type of flooring to be installed. For example, thinner plywood or OSB panels may be suitable for vinyl flooring. While others demand a more substantial foundation, such as ceramic or porcelain tiles.

Thickness flexibility

Explore the flexibility of each material concerning thickness. Thicker plywood might offer rigidity for specific applications, while thinner OSB could be advantageous in scenarios where flexibility is key.

Temperature tolerance

Consider how thickness influences temperature resilience. Thicker panels, whether plywood or OSB, may better withstand extreme temperatures, ensuring stability in various climates.

Plywood subfloor materials for various size jobs  

We recognise the importance of selecting the right subfloor material for your construction projects. Plywood sheets stand out as a top-tier choice. It provides a solid foundation for flooring installations. Our extensive range caters to the diverse needs of both residential and commercial jobs. Explore the benefits of plywood for subfloors with Building Materials Nationwide, where quality meets reliability. 

We also understand the unique needs of trade customers. Trade customers are invited to open trade accounts with us. By opening a trade account, you gain access to an efficient procurement process with the help of your trade account manager. This ensures that your projects are supported by top-quality materials every step of the way.

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