Sawn timber has been cut from the log into the required section but retains a relatively rough sawn surface. It is commonly used where appearance is less important, including structural work, framing, fencing and general construction.

Planed timber has been machined to create a smoother and more consistent surface. The amount of machining and the final profile depend on the particular product.

PSE stands for Planed Square Edge. It generally describes timber that has been machined to produce a smooth finish and square edges. It is commonly used for joinery, shelving, furniture and visible timber work.

See the Plywood Etc planed timber range.

PAR means Planed All Round. The term is widely used for timber that has been machined on all four faces. PSE and PAR are often used interchangeably in the UK timber trade, although individual suppliers may use the terms slightly differently.

DAR means Dressed All Round. You are more likely to encounter the term in Scottish timber and construction terminology. In practical buying situations it can refer to fully dressed or machined timber, broadly comparable with terminology such as PAR in other parts of the UK.

Always check the supplier's product description and finished dimensions rather than relying on the abbreviation alone.

Regularised timber has been machined to give more consistent dimensions and a more uniform section. It is commonly encountered in construction timber and carcassing products where consistent sizing is useful during installation.

Important: regularised does not necessarily mean fully planed smooth like PSE or PAR.

Carcassing is a trade term for structural or construction softwood used to create the framework of buildings and other structures. Common applications include walls, roofs, floors, studwork, joists and general framing.

CLS is commonly understood as Canadian Lumber Standard. CLS timber is machined with rounded or eased edges and is widely used for internal studwork, partitions, framing and general DIY construction.

C16 is a recognised structural strength class for graded timber. Strength grading is intended to predict structural performance so timber can be assigned to an appropriate class.

C16 is commonly used in UK construction applications, subject to the requirements of the particular design and specification.

C24 is a structural strength class with higher specified characteristic strength values than C16. It is commonly selected where the design calls for the higher strength class.

C24 is not simply a visual grade: it is a strength classification determined through grading.

The correct treatment and specification are particularly important for fence posts because they can experience persistent exposure to moisture and, depending on installation, ground contact.

For timber intended for ground contact, look for a specification suitable for Use Class 4.

Feather edge boards are tapered fencing boards used to create close-boarded fencing. The overlapping arrangement helps create a solid, traditional fence line.

An arris rail is a shaped horizontal rail commonly used in traditional closeboard fencing to support the fence boards between the posts.

A gravel board sits at the bottom of a fence to keep the main fence boards away from direct contact with soil and standing moisture. Gravel boards can be made from timber, concrete or other materials.

Use Class 3 applies to timber used outdoors and above ground where it is exposed to weather and wetting. It is therefore relevant to many exterior applications such as suitable fencing components, decking boards and cladding.

Use Class 3 can be divided into situations where timber dries more quickly and situations where it may remain wet for longer.

Use Class 4 applies to timber in direct contact with the ground and/or fresh water. It is particularly important for applications such as fence posts and other components exposed to substantially higher moisture risk.

For exterior structural support, current industry guidance can also recommend UC4 treatment even where there is no direct ground contact.

Pressure treatment is a factory-controlled process used to introduce wood preservative into timber. The required treatment specification should be matched to the timber's intended end use.

Plywood is a wood-based panel made from layers of veneer bonded together, normally with adjacent layers arranged with their grain directions at right angles. Different plywood constructions and grades are suited to different applications.

Browse Plywood Etc plywood.

Hardwood plywood uses hardwood veneers in its construction. It is widely used for furniture, joinery, cabinetry, fabrication and other projects where strength, appearance or machining characteristics are important.

See the hardwood plywood collection.

MDF stands for Medium Density Fibreboard. It is a manufactured wood-based panel commonly used for furniture, cabinetry, shelving, interior joinery and painted projects.

Browse MDF sheets.

OSB stands for Oriented Strand Board. OSB3 is a commonly specified structural panel grade for use in humid conditions and is widely encountered in construction applications.

Browse the Plywood Etc OSB range.

Chipboard, also known as particleboard, is made from wood particles bonded together. Different grades and finishes are manufactured for applications including furniture, flooring and general interior work.