PAR timber is one of those terms that appears frequently in joinery and construction but is not always clearly understood by buyers who are new to specifying timber. PAR stands for planed all round, meaning the timber has been processed through a planer on all four faces to produce a smooth, accurately dimensioned section that is ready for use without further preparation.
In solid oak, PAR sections are among the most practically useful materials in any joinery project, suited to a wider range of applications than most buyers initially appreciate.
This guide explains what PAR oak is, how it differs from sawn timber, the principal sizes available, and the applications that make it the right specification choice.
PAR vs Sawn Timber: Understanding the Difference
Timber leaves a sawmill in one of two principal states. Sawn timber, sometimes called rough sawn or PSE (planed square edge, where only two faces are planed), has an uneven surface texture left by the saw blade and dimensions that are the nominal target size rather than the finished size. Sawn sections are typically used where the surface will not be visible, where further machining will be carried out, or where structural rather than joinery applications are intended.
PAR timber has been run through a planer on all four faces to produce a smooth, even surface with accurate, consistent dimensions. The planing process removes material from each face, so a PAR section is always slightly smaller in actual finished dimension than the nominal size it is specified at. A 50mm x 50mm nominal PAR section typically finishes at approximately 44mm x 44mm after planing. This is a standard industry convention and should be accounted for when planning joint fits and clearances. The oak PAR timber range covers a wide selection of sections in solid American white oak, available in standard lengths for immediate despatch.
Why Solid Oak PAR Is Worth the Investment
Oak PAR is more expensive than pine or softwood PAR of the same nominal section, and the cost difference is meaningful, particularly at larger sections and longer lengths. The justification for the premium lies in oak's combination of properties that no common softwood can match: hardness, durability, visual grain character, and longevity. A piece of oak joinery made from PAR sections will outlast pine equivalent many times over in most applications, and the natural grain of solid oak provides a finish quality that painted pine cannot replicate in a natural or oiled scheme.
For painted applications where the timber will be fully covered, pine PAR is the more economical and entirely appropriate choice. For any application where the natural timber is visible, where the surface will be oiled, waxed, or lacquered to show the grain, or where material quality and longevity are priorities, solid oak PAR represents the correct and worthwhile specification. The broader oak joinery parts range covers the full selection of PAR sections alongside mouldings, skirting, architrave, wall cladding, shelving, and window boards to complete a joinery scheme consistently in solid oak.
Common Applications for Oak PAR Timber
The versatility of PAR sections means they appear across a very wide range of joinery applications. The most common include:
- Shelving and shelf supports: solid oak PAR in 25mm and 32mm thicknesses is widely used for shelving where the natural timber surface is part of the intended aesthetic; wider board sections produce shelves with a clean, solid appearance that veneered or painted board alternatives cannot match
- Cabinet and furniture making: PAR sections form the structural framework of bespoke cabinets, wardrobes, alcove units, and fitted furniture, either as concealed structural members or as visible frame elements in a natural oak scheme
- Framing and grounds: smaller PAR sections in 25mm x 50mm and 38mm x 50mm sizes are used as grounds for skirting boards, concealed framing behind wall panelling, and structural grounds for other applied finishes
- Window boards and sills: wider PAR sections form solid oak window boards, providing a hardwearing and visually attractive sill surface that out-performs painted softwood in durability and appearance
- Bespoke moulding stock: trade joiners and woodworkers use PAR sections as the raw material for machining bespoke moulding profiles, architrave, and beading where standard off-the-shelf profiles do not meet the specific requirements of a project
- Staircase components: smaller PAR sections are used for packing, scribing, and infill work associated with staircase renovation and installation
Sizes and Section Selection
Oak PAR sections are available across a range of widths and thicknesses that cover the vast majority of joinery requirements. Common sections include 25mm x 25mm, 25mm x 50mm, 50mm x 50mm, 25mm x 75mm, and larger widths for shelving and window board applications. The right section for a given application depends on the structural requirement, the desired visual weight of the finished component, and the clearances available at the fixing and joining points.
When selecting section sizes for a project, it is important to work from the finished dimensions rather than the nominal sizes, as the planing process reduces each dimension. Detailed section drawings or a test cut from a sample length will confirm the actual finished dimensions before cutting a full project quantity. Ordering a small overage beyond the calculated requirement is standard practice to allow for any waste from mis-cuts or minor defects in individual lengths.
Finishing Oak PAR Timber
Solid oak PAR arrives ready to use in terms of surface preparation, but a finish should be applied both for aesthetic reasons and to protect the timber from moisture, soiling, and surface wear. The choice of finish depends on the application and the desired appearance. A hard wax oil produces a natural, slightly enriched finish that protects the surface while allowing the grain to read clearly, and is appropriate for most internal joinery applications including shelving, window boards, and cabinet work. A clear satin or matt lacquer provides more surface protection and easier cleaning in high use applications. For components that will be painted, a primer applied before undercoat prevents resin bleed and ensures consistent paint adhesion across the oak surface. Oak skirting and architrave should always be finished in the same product as adjacent PAR components to maintain a consistent sheen and colour across the full joinery scheme.
Frequently Asked Questions
What does PAR mean in timber?
PAR stands for planed all round, meaning all four faces of the timber section have been machined smooth on a planer to produce consistent, accurate dimensions and a clean surface ready for use without further preparation.
Why is the finished size of PAR timber smaller than the nominal size?
Planing removes material from each face to achieve a smooth surface, reducing the section slightly below the original sawn size; a nominal 50mm x 50mm section typically finishes at around 44mm x 44mm after planing on all four faces.
Can oak PAR timber be used outdoors?
Oak has reasonable natural durability and can be used in covered external applications such as porches and canopies, but for fully exposed outdoor use a preservative treatment or an exterior-grade oil finish should be applied and maintained periodically to protect the timber.
What is the difference between PAR and joinery grade oak?
PAR sections are planed to consistent dimensions and smooth surfaces but may include some natural characteristics such as small knots; joinery grade oak is selected for cleaner grain and fewer natural features, making it more appropriate for high-specification visible joinery applications.
Final Thoughts
Oak PAR timber is one of the most versatile and practical materials in any joinery project, combining the visual character and durability of solid oak with the dimensional accuracy and surface quality that ready to use applications require. Whether the project is shelving, cabinet framing, window boards, or bespoke moulding stock, PAR sections in the right sizes eliminate preparation time and produce a quality of finished result that sawn timber or softwood alternatives cannot match in a natural oak scheme.
Browse the full range of solid oak timber joinery parts at Oak Store Direct to find the right sections, lengths, and grades for your project.