Quality & Grade
Timber and plywood quality and grades can be confusing, so we have put together this useful guide to answer some of the common questions you may have.
What Grades Of Plywood Are There?
Plywood is a versatile building material that comes in various grades, each with its unique characteristics and uses. The plywood grades are:
- Grade A – This is the highest quality and has no visible defects or knots on either side. It is smooth, sanded, and perfect for furniture and cabinetry.
- Grade B – This plywood will have some visible defects, such as small knots, but is still of good quality. It is typically used for interior applications such as paneling and subflooring.
- Grade C – These products may have knots and splits, which can be repaired/filled but will still provide a smooth sanded surface suitable for a wide variety of applications.
- Grade D – This plywood may have visible defects, including knotholes, splits, and cracks, and is typically unsanded. It is used for rough construction type applications.
It’s essential to choose the right grade of plywood for your project to ensure optimal performance and longevity. When the letters are used together to describe a sheet of plywood, they are describing the face appearance. For example C/D – One good sanded face, one rough face.
What Is Seconds Grade Plywood?
Seconds grade plywood is a lower grade of plywood that may have more visible defects and inconsistencies than the grades described above. These defects can include knots, splits, cut out of square, and uneven thickness. Seconds grade plywood is sold at a lower price compared to higher grades. It is often used for non-structural applications where appearance is not a priority, such as temporary construction or DIY projects. It is important to check if seconds grade plywood is suitable for your project. Please see our terms and conditions for more detail.
What is seconds grade timber?
Seconds grade timber refers to timber that has a lower grade of appearance and quality compared to the higher grades such as premium or standard appearance grade. This type of timber may have defects such as knots, splits, wane, or other blemishes that make it unsuitable for use in applications where appearance is a top priority.
Despite its lower grade, seconds grade timber is still suitable for use in many applications, such as in non-structural building elements like decking and fencing, or in the framing of sheds, barns, or other outbuildings.
Seconds grade timber is typically sold at a lower cost than higher grade timber due to its lower quality and appearance. It may be a good option for those who want to save money on their timber needs, but who still need a reliable and durable material.
What's the difference between structural and non-structural timber and plywood products?
Structural timber and plywood products are designed and graded specifically for use in load-bearing applications, such as in framing, trusses, beams, and columns. These products are typically made from a stronger and denser type of wood, and are graded based on their strength, stiffness, and other mechanical properties. They are also tested and certified to meet specific structural performance standards, such as those set by building codes and industry organisations.
Non-structural timber and plywood products, on the other hand, are designed for use in applications where load-bearing capacity is not a primary concern. These products are often made from a softer or less dense type of wood, and are graded based on their appearance and other aesthetic qualities. Non-structural timber products may be used in applications such as furniture, cabinetry, and decorative trim, while non-structural plywood products may be used in wall and ceiling paneling, shelving, and other interior applications.
It’s important to note that while non-structural timber and plywood products may not be designed for load-bearing applications, they still need to meet certain quality and safety standards to ensure that they are suitable for their intended use. It’s always recommended to consult with a building professional or supplier to determine the appropriate type of timber or plywood product for your specific needs.
What types of timber treatment are used in NZ?
In New Zealand, there are several types of timber treatments used to protect wood from decay, insects, and other forms of damage. These treatments include:
- CCA (Copper Chrome Arsenic) treatment. This is a chemical treatment that involves impregnating the wood with copper, chrome, and arsenic to protect against insects, fungi, and decay.
- LOSP (Light Organic Solvent Preservative) treatment. This treatment involves impregnating the wood with a solvent-based preservative, such as boron or permethrin, to protect against insects and fungi.
- ACQ (Alkaline Copper Quaternary) treatment. This is a newer type of treatment that uses copper and a quaternary ammonium compound to protect against insects and fungi. It is considered more environmentally friendly than CCA treatment.
- Thermal modification. This is a process that involves heating the wood to a high temperature to change its properties, making it more resistant to decay, insects, and other forms of damage.
- Paint and stain. Painting or staining wood can also provide some protection against decay and weathering.
It’s important to note that some types of timber treatments may have potential health and environmental risks, so it’s important to carefully consider the type of treatment used and follow proper safety guidelines when handling treated wood.
What is Laminated Veneer Lumber (LVL)
Laminated Veneer Lumber (LVL) is an engineered wood product that is made by bonding thin layers of wood veneers together using high-quality adhesive. The resulting material is exceptionally strong, stable, and resistant to warping, splitting, or cracking, making it an ideal choice for use in structural applications.
LVL is available in a wide range of sizes and thicknesses, and it is often used in place of traditional solid wood products like timber beams, columns, and headers. Its uniformity and strength make it a popular choice in construction, and it is often favoured by builders and architects who are seeking to maximize the structural performance of their projects while reducing the overall weight and cost of materials. Additionally, because LVL is made from fast-growing species of wood, it is a sustainable and environmentally friendly choice for those seeking to minimize the environmental impact of their building projects.