Everything You Need to Know About PSE Timber: A Versatile Construction Material

PSE timber refers to Planed Square Edge timber, which is a type of wood that has been machined on all sides to create a smooth, flat surface with square edges. This is different from rough-sawn timber, which is cut to size but remains rough and unfinished. PSE timber is used in various construction, DIY, and carpentry projects due to its consistency, smoothness, and ease of use.

1. Manufacturing Process

The process of creating PSE timber involves planing rough-sawn timber to remove the rough outer surface and shape the wood to specific dimensions. The planing process makes the timber smoother and more uniform, with square edges that allow for precise fitting during construction. The timber is often kiln-dried before planing, which reduces its moisture content and prevents warping or splitting. After this, the timber undergoes planing on all four sides to achieve the smooth, clean finish required for PSE timber.

2. Types of Wood Used

PSE timber is available in various types of wood, including softwoods like pine, spruce, and for, as well as hardwoods like oak, ash, and mahogany. The choice of wood depends on the intended use, budget, and aesthetic preference. Softwoods are commonly used in general construction and framing because they are more affordable and readily available. Hardwoods, on the other hand, are typically used for furniture-making, decorative applications, and where higher durability and aesthetic quality are needed.

3. Sizes and Dimensions

PSE timber comes in a wide range of dimensions, from smaller sizes suitable for decorative mouldings and trim work to larger beams and planks used in structural work. The dimensions are typically specified in millimetres, and because the timber has been planed, the actual dimensions of the wood are slightly smaller than the original rough-sawn size. For example, a PSE timber piece labelled as 50mm x 100mm may have actual dimensions of 45mm x 95mm after the planing process.

4. Uses and Applications

PSE timber is a popular choice for internal joinery, furniture-making, and DIY projects due to its smooth surface, which requires minimal sanding and is ready for finishing. It is commonly used for:

• Skirting boards
• Architraves
• Shelving
• Doors and windows frames
• Furniture construction
• Decorative projects

Its smooth surface makes it ideal for painting, staining, or varnishing, providing a clean and finished look with minimal preparation.

5. Advantages

PSE timber offers several advantages:

• Ease of use: Its smooth surface and square edges make it easy to handle and work with, reducing the need for additional planing or sanding.
• Uniformity: The uniform size and finish ensure that PSE timber fits perfectly with other components, making it ideal for precise construction projects.
• Aesthetics: The smooth, clean surface allows for easy application of finishes like paint or varnish, improving the aesthetic appeal of the finished product.
• Durability: Kiln-dried PSE timber is more resistant to warping, shrinking, and splitting, which enhances its longevity in various applications.

6. Considerations

While PSE timber has many advantages, there are a few factors to keep in mind when using it:

• Cost: Planing adds to the overall cost of the timber, so PSE timber is usually pricier than rough-sawn timber.
• Suitability: It may not be ideal for outdoor applications unless treated with appropriate preservatives, as untreated wood is susceptible to moisture and insect damage.
• Reduced size: Since PSE timber is planed, its final size is smaller than rough-sawn timber, so careful consideration is needed when ordering for specific dimensions.

In summary, PSE timber is a versatile and practical material, offering a smooth finish and precise dimensions that make it well-suited for internal joinery, furniture-making, and other DIY projects. Its planed surface allows for easy application of finishes, and it is available in a wide range of sizes and types to accommodate various needs.

Typical PSE Timber Sizes in the UK for Various Applications

In the UK, PSE (Planed Square Edge) timber comes in various sizes depending on the type of project and application. The actual dimensions of PSE timber are slightly smaller than the nominal sizes due to the planing process. The sizing and thickness are standardised, and here’s a breakdown of common sizes for different applications:

1. Construction

For general construction and framing, PSE timber is often used for non-structural elements like partition walls, skirting, and door linings. Common sizes include:

• 38mm x 63mm (Actual size: 33mm x 58mm)
• 38mm x 89mm (Actual size: 33mm x 83mm)
• 50mm x 100mm (Actual size: 45mm x 95mm)
• 75mm x 225mm (Actual size: 70mm x 220mm)

These larger sizes are ideal for framing and creating partition walls, window/door linings, and other internal carpentry work.

2. Joinery and Internal Finishing

PSE timber is widely used for internal joinery, such as architraves, skirting boards, and shelving. Popular sizes for this purpose are typically smaller and more precise, like:

• 25mm x 50mm (Actual size: 20mm x 45mm)
• 25mm x 75mm (Actual size: 20mm x 70mm)
• 50mm x 75mm (Actual size: 45mm x 70mm)
• 50mm x 150mm (Actual size: 45mm x 145mm)

These sizes are ideal for making door frames, window casings, shelving, and other decorative features.

3. Furniture Making & Fine Woodworking

For furniture making and more delicate fine woodworking tasks, smaller PSE timber sizes are typically used. These provide precise edges and smooth surfaces, making them easy to work with for crafting furniture pieces and decorative items. Common sizes include:

• 19mm x 38mm (Actual size: 14mm x 33mm)
• 19mm x 75mm (Actual size: 14mm x 70mm)
• 25mm x 50mm (Actual size: 20mm x 45mm)
• 25mm x 100mm (Actual size: 20mm x 95mm)

These thinner, narrower sections of PSE timber are suitable for drawer fronts, furniture panels, shelving, and trim work. The smooth surface and straight edges help achieve a high-quality finish without extensive sanding or shaping.

4. DIY Projects & Home Improvements

For general DIY projects, such as building shelving units, workbenches, or storage racks, PSE timber is a popular choice because of its versatility and ease of use. Common sizes for DIY work typically fall into the following categories:

• 25mm x 38mm (Actual size: 20mm x 33mm)
• 25mm x 50mm (Actual size: 20mm x 45mm)
• 38mm x 50mm (Actual size: 33mm x 45mm)
• 50mm x 75mm (Actual size: 45mm x 70mm)

These sizes offer flexibility for smaller woodworking projects, ensuring strength, smoothness, and ease of fitting.

5. External Joinery

For external joinery, where timber might be exposed to the elements, larger PSE timber sizes are often treated with preservatives to prevent decay. Typical sizes for fascias, soffits, and exterior frames include:

• 38mm x 100mm (Actual size: 33mm x 95mm)
• 50mm x 150mm (Actual size: 45mm x 145mm)
• 75mm x 200mm (Actual size: 70mm x 195mm)

These are suitable for outdoor projects where durability and weather resistance are key considerations.

Summary of Typical PSE Timber Sizes in the UK:

Application	Common Sizes (Nominal)	Actual Sizes (After Planing)
Construction & Framing	38mm x 63mm, 50mm x 100mm	33mm x 58mm, 45mm x 95mm
Joinery & Finishing	25mm x 50mm, 50mm x 150mm	20mm x 45mm, 45mm x 145mm
Furniture Making	19mm x 38mm, 25mm x 50mm	14mm x 33mm, 20mm x 45mm
DIY Projects	25mm x 38mm, 50mm x 75mm	20mm x 33mm, 45mm x 70mm
External Joinery	38mm x 100mm, 75mm x 200mm	33mm x 95mm, 70mm x 195mm

These sizes provide a guide to what’s typically available and suitable for different woodworking applications, from heavy-duty construction tasks to intricate woodworking projects.