Planed Timber

What Is Planed Timber?

Planed timber refers to wood planks or boards that have been machined to create a smooth, even surface on at least one side - usually on all four sides. In other words, it starts as rough-sawn timber and then is planed down (surfaced) to remove the rough saw marks, resulting in a smooth, uniform finish. Planing is typically done with an electric planer or industrial planing machine, which shaves off a thin layer of wood to produce flat, even faces and precise dimensions.

There are a couple of terms you’ll encounter in this context:

• Planed All Round (PAR): This means the timber has been planed smooth on all faces all the way around the piece (all four sides/edges are planed). It’s sometimes also called “dressed all-round” or simply smooth-planed timber.
• Planed Square Edge (PSE): Traditionally, PSE refers to timber that has been planed on one or more sides to give at least one square, straight edge. However, in many trade contexts, PSE timber is used interchangeably with PAR to describe boards that are planed on all faces with sharp, square edges (as opposed to rounded edges). Essentially, both PAR and PSE usually indicate a piece of timber that is completely planed, smooth and has square edges.

Planed timber is sometimes also just called “finished timber” or “dressed timber,” emphasising that it has been brought to a finished state. It’s commonly sold in standard sections (e.g. 50x150mm) with the understanding that the surfaces are smooth and the edges are true (90-degree angles, unless intentionally eased). This makes it a popular choice for any application where the wood will be visible, handled, or needs to fit together precisely.

Applications

• Internal Joinery: Planed timber is a staple for interior woodwork or joinery projects. This includes things like skirting boards, architraves, door frames, and window frames/linings. These components are visible in a finished room, so having smooth, planed wood means they’ll look neat and take paint or varnish nicely. 
• Furniture Making: Many furniture pieces are built from planed timber sections. Whether you’re constructing a simple bookshelf or a custom table, starting with PAR/PSE boards speeds up the build. Shelves, table tops, chair legs, bed frames, cabinets, and other furniture parts often use planed all round wood so that all visible surfaces are smooth. 
• Decorative Trim and Mouldings: Planed timber is the basis for most decorative mouldings. For example, before a piece of timber becomes a crown molding, picture rail, or dado rail with a profile, it’s first planed smooth. Even if you’re installing a simple square-edge trim or a window board (stool), you’d use planed wood for a clean look. Planed timber is also used for making staircase parts (like stringers, treads that will be carpeted, or handrail blanks before profiling).
• Flooring and Cladding: While finished flooring and cladding often have specialised profiles (tongue-and-groove, etc.), these products start as planed timber too. In some cases, people might use basic planed planks for a rustic but smooth wood flooring or for interior wall cladding/panelling. Planed boards can be used as floorboards (e.g., whitewood pine flooring) or as visible ceiling or wall cladding in sheds and cabins.
• Shelving and DIY Projects: Planed all round timber is popular for making shelves and general DIY constructions like workbenches, storage racks, garden planters, or any project where you want a neat finish without a lot of additional work. It’s also commonly sold in home improvement stores for hobbyists building things like birdhouses, small furniture, or repair jobs.
• Doors and Windows: Planed timber sections are used in making door jambs, window sashes, and casings. For instance, traditional sash windows use planed timber for the sashes and frames so that they slide smoothly and have an attractive appearance. 
• Structural Framing (Studwork): Stud timber for partition walls, especially the popular CLS timber (Canadian Lumber Standard), is planed with eased edges. The reason is that planed, eased-edge studs are easier and safer to handle on site (no splinters, no sharp corners) and provide consistent dimensions. 
• Outdoor Projects (with treatment): Planed timber can be used in exterior applications too, provided the wood is suitably treated or naturally durable. For example, decking boards are often planed on the top surface (sometimes with grooves cut for grip on one side and planed smooth on the other). Planed and pressure-treated lumber is used for things like fence rails, pergola components, or garden furniture, because it has a nice finish to touch. Keep in mind that if you use planed softwood outside, it should be pressure treated or painted with a preservative, as smooth wood can still be prone to rot if unprotected outdoors.

Benefits

• Smooth, Clean Surface: No roughness or saw marks means no splinters and a clean look. This is safer and more pleasant to handle and gives a professional appearance to your project.
• Ready to Use & Easy to Work: Because it’s already smooth and dimensionally accurate, planed timber requires minimal preparation. You generally only need a light sanding (if that) before applying paint, varnish, or stain. This saves time compared to starting with rough timber that would need extensive planing or sanding.
• Precise Dimensions & Square Edges: Planing brings timber to consistent finished dimensions with square edges, which makes assembly and joinery easier. Pieces of planed timber are uniform in size and will fit together reliably for frames, panels, and joints. The accuracy reduces guesswork and allows for tight fits in construction or cabinetry.
• Versatility: It can serve both structural roles (e.g. framing, when graded appropriately) and finish roles (like trim or furniture). Its smoothness also allows it to be used in applications where people will frequently touch the wood (handrails, furniture surfaces) without worry.
• Better Finish Adhesion: Paints, stains, and sealants go on evenly over a smooth surface. Planed wood tends to accept finishes more uniformly than rough wood, leading to a better end result. There are no deep grooves or rough fibres to obscure or soak up too much finish.
• Professional Quality Results: Enables a more professional-looking outcome with less effort since the difficult work of smoothing and truing the wood has already been done at the mill.