What is a Subfloor?
The Foundation Specialists at Geotech Built Explain What a Subfloor is and Why it's So Important
When considering flooring options, we often jump straight to the finish—whether it’s the warmth of wood or the comfort of carpet. But before making that choice, it's essential to think about what's underneath: the subfloor.
The subfloor is vital to your floor’s structure. It’s comprised of many layers and what you see is just the topmost later. If you’re wondering what a subfloor is and what role it plays in any structure, you've come to the right place.
Sub-flooring is a crucial part of your floor’s architecture. Typically, when you look at your floor as a cross-section, it would look like a sandwich. These sections include the top floor and joists at the bottom. The joists support the floor.
Additionally, there is a layer between the subfloor and flooring known as the underlayment. It is often referred to as a subfloor as well. This layer may need to be installed, but that depends on the type of flooring you’ll install once the structure is complete.
Why Do You Need a Subfloor?
A subfloor is crucial for almost every building because finished flooring alone isn't strong enough to support daily foot traffic. Certain types of flooring may require specific subfloors, much like a stone needs a firm base. Consulting professionals before installation is always wise to avoid costly mistakes and ensure the best results.
Concrete basements may not need a subfloor for materials like carpet or tile. Floating floors such as engineered hardwood and laminate can be installed directly on concrete to create an even surface. However, traditional hardwood flooring may require an additional subfloor on concrete to ensure a firm, stable floor.
Choosing the right subfloor is vital for a sturdy and visually appealing floor. Below are the different types of subfloors commonly used in Australia to consider:
- Plywood: Plywood is made from sheets of wood veneer glued together with an adhesive, resulting in a strong and flat material. It's also cost-effective, making it a popular choice for residential homeowners. Plywood's durability and affordability make it ideal for subflooring under various types of finished flooring.
- Particleboard: Particleboard is composed of small wood chips that resemble sawdust, pressed together to form sheets. It is weaker than plywood and not suitable for areas prone to moisture. Its lower strength limits its use as a subfloor, particularly in bathrooms, kitchens, and other damp environments.
- Concrete: Concrete subfloors are commonly found in bathrooms, basements, apartments, and high-rises due to their strength and durability. While much stronger than particleboard, concrete should be thoroughly inspected for cracks and flaws before installation to ensure a smooth and stable foundation for the finished floor.
- Oriented Strand Board (OSB): OSB is made from large wood pieces pressed together with glue, forming a dense and consistent structure. While it provides a strong subfloor, OSB dries out slower than plywood, which can lead to moisture damage. It is essential to weigh the pros and cons of OSB before choosing it as a subfloor material, considering the specific needs of your home and the type of flooring you plan to install.
By understanding the different types of subfloor materials and their characteristics, you can make an informed decision that ensures the durability and stability of your finished floor.
Understanding the Key Components of Your Floor
Joists
Joists are essential structural elements found in every home, supporting the entire floor structure above. They are typically made from dimensional lumber or laminated wood and span the entire house. If you're curious about how joists look, you can see them in an unfinished attic or ceiling. Ensuring that your joists are well-maintained is crucial to prevent issues like rotting and water damage. In homes without a basement, which are built on a cement slab, joists are not needed for support. Instead, the flooring structure starts with the subfloor.
Subfloor
The subfloor is a foundational layer that rests on the joists and is usually made of OSB or plywood about 1 1/8 inches (approximately 28mm) thick. This layer supports all the layers on top and endures the weight of foot traffic. If not properly fastened, the subfloor can produce noise. It's typically secured to the joists with screws, nails, or glue to ensure stability. In concrete subfloor setups, an underlayment is placed on top to absorb heat from the ground and act as a barrier, preventing heat transfer. This layer also prevents tiles from cracking due to temperature fluctuations or existing cracks in the concrete subfloor.
In cases where the subfloor is made of concrete, an underlayment layer is often installed. This layer serves multiple purposes, including absorbing heat from the concrete, acting as a barrier to prevent heat transfer, and providing a buffer that helps prevent tiles from cracking during installation. The underlayment is also essential for maintaining the efficiency of floor-heating systems by preventing heat from traveling downward into the slab. Typically, a floor heating system is installed on top of the subfloor, and many systems are compatible with both concrete and wood subfloors.
The Surface
The surface is the visible layer of the floor and can consist of materials like tiles, wood, or carpet. This layer is primarily added for aesthetic purposes and makes a significant first impression when entering a home or office. Although it is the most visible part of the floor, the surface layer relies heavily on the stability provided by the subfloor and underlayment. In the event of subfloor damage, adding another layer on top, such as plywood over particleboard, can provide a practical solution to enhance strength and prepare for a new surface finish.
Final Thoughts
Ensuring a firm subfloor is crucial for maintaining the quality and longevity of your flooring. Consulting with professionals before updating your flooring can help you understand the specific needs of your subfloor, avoid costly mistakes, and ensure the structural integrity of your entire home. A well-maintained subfloor not only supports your flooring but also protects your investment in the long term.
By understanding the different parts of a floor and their functions, you can make informed decisions that enhance the durability and aesthetics of your flooring. Whether you're dealing with joists, subfloors, underlayment, or surface layers, each component plays a vital role in the overall structure of your home.
Understanding the various components of your floor, from joists and subfloors to underlayment and surface layers, is crucial for maintaining a strong and durable home. In Australia, homes often face unique challenges such as soil movement and moisture, making foundation stability even more important. Geotech Built specialises in comprehensive foundation solutions, including restumping, underpinning, pier replacement, and general foundation repairs throughout Sydney and NSW. These services ensure that your home remains safe, stable, and long-lasting. If you're needing to address structural concerns, our expert team is here to provide tailored, reliable solutions that protect your investment and enhance your living space.
