Builders Glossary: 30 Construction Terms You've Seen But Never Knew

Aggregates

Aggregates in simple terms are a mix of several coarse or medium ground materials use in the production of concrete and mortar. The addition of Aggregates to a concrete mixture can give the finished product a number of desirable qualities, such as extra stability, volume and erosion resistance.

Anchor Bolts

Anchor Bolts are a type of fastener used to connect structural and non-structural elements to concrete, typically any elements made of steel. There are several different types of Anchor Bolts, designed to connect different types of materials to concrete, so it is advised to do some research in to which type is right for your project.

Arris

Arris is the sharp edge that is formed by the intersection of two surfaces. In construction, this usually comes in the form of Arris Rails, the triangular battens of timber which are common place in standard fencing. Other forms of Arris include corners of masonry units and the junction between two planes of plaster.

C16/C24

C16 and C24 are two different structural grades of timber, the confusion can sometimes lie between the difference between the two. Both are high quality and strong types of timber, but C24 is the higher graded out of the two. C24 has the added benefits of being able to handle higher loads and wider spans. However, C24 comes with a more premium price tag as it can only be sourced from slower growing trees to achieve the tighter grain it is known for.

Chamfer

Chamfer is a carpentry term used to describe the shape of wooden detailing and edging such as skirting boards. Chamfer’s design is distinguished by its sloping corner, then continuing in a straight line to the bottom of the board. Chamfer’s design is not only for aesthetic purposes, the lack of sharp edges enhances safety and limits damage to the edges themselves.

Composite

Composite, in its scientific terms is: “a material produced from two or more constituent materials with notably dissimilar chemical or physical properties that, when merged, create a material with properties, unlike the individual elements.”. In terms of construction, composite materials are mainly known for their use in decking and fencing. In this case, the composite material is a mix of plastic, wood and a small amount of bonding agents that are hot pressed together to form boards. If you want to learn more about Composite Decking and its benefits over traditional Timber Decking, check out our post on the topic here.

Cross Grain

Cross Grain is a term used to describe a piece of wood or material that has v grooves that travel along the shorter edge. In the case of flexible sheets such as MDF or Plywood, this would mean that the sheet would bend round so the grain pattern would be consistent if the shorter edge were to meet the other shorter edge.

Feather Edge

Feather Edge is a common type of fence boards. These boards get their name from the fact that they are tapered, starting with a thicker edge transitioning to a thinner edge on the other side. The use of Feather Edge boards are common place because this design allows the boards to overlap perfectly, allowing for no gaps in the finished fence panel.

Gypsum

Gypsum is a soft sulphate material used in the product of most plasterboards, drywall and blackboards. The material is mainly comprised of calcium sulphate dihydrate and in the case of plasterboard, is pressed between two sheets of thick paper to create a board that is prized for its compact nature but not compromising on its insulation qualities.

Joist

Joists are structural components to most building construction projects. Usually used in conjunction with beams, you will usually find joists in ceilings, under flooring and under decking, to provide structural support and tying together the walls to the ceiling and/or floor to provide complete structural integrity.

Knot

Knots in wood or veneer are most commonly referred to as imperfections in the wood as they disrupt the smooth and continuous grain of the rest of the board or batten. These knots are caused by the wood being cut from a part of the tree that had branches growing from it, meaning that the growth of these branches caused the grain to grow around them, causing a gap in the flow of grain.

Load-Bearing Wall

A Load Bearing Wall is a type of wall that is essential to the structural integrity of a building. The load-bearing name comes from the fact that due to the wall being a structural element, it is also responsible for bearing the load of any weight that may be above the wall, on a second floor of a building for example.

Long Grain

Similar to Cross Grain, Long Grain instead has the v groove travelling along the longer edge of the sheet instead of the shorter edge. With that in mind, it would mean that in the case of flexible sheets, the sheet would bend round so the grain pattern would be consistent if the longer edge were to meet the other longer edge.

Masonry

Masonry is simply the term used to describe the process of working with stone, brick or concrete. This involves the process of laying bricks and blocks to create walls, as well as the construction of poured concrete, both reinforced and unreinforced.

MDF

MDF, or Medium Density Fibreboard, is a very commonly used material made of wood fibres, waxes and resins pressed together to a desired thickness. This interior board is desired for its clean finish and has a number of variations with different specific qualities to create panels and fixtures for all spaces, with Moisture Resistant MDF being ideal for kitchens, bathrooms and boiler rooms, and Fire Retardant MDF for offices, cinemas and industrial buildings.

Melamine

Melamine is a chemical compound, similar to plastic, that can imitate other materials in both appearance and versatility. Melamine has mainly been used in the manufacturing of dinnerware, due to it being more lightweight and less prone to shattering. As well as this, it is also placed over sheet materials such as MDF to create a smooth, usually black or white finish, making it perfect for the construction of household units. Melamine has a mass of 67% nitrogen, and because of this, also has excellent fire-retardant properties.

OSB

OSB, or Oriented Strand Board, is a versatile softwood panel, mainly used in the construction of flooring and roofing. The strips and flakes of wood are coated in an adhesive resin and the specific placement of these flakes when hot-pressed produces a structured, versatile and moisture resistant panel. This panel also benefits from excellent load bearing capabilities, and the OSB/3 Boards we stock have the added benefit of being able to hold up well under high humidity.

Phenolic Resin

Phenolic Resin is a synthetic polymer prized for its durability and resistance qualities. In the construction world, Phenolic Resin is impregnated into a film that is pressed on to both sides of either hardwood or birch plywood to create a board that is mainly used for the flooring of trailers, horse boxes and exterior to interior pathways due to its anti-slip properties.

PIR

PIR, or Polyisocyanurate, is a type of insulation used in both commercial and domestic settings. Hailed as the most effective and efficient form of insulation, this rigid foam board sandwiched between two sheets of aluminium foil is placed in areas that experience heat loss to create a durable yet extremely energy efficient insulation system.

PVC

PVC, or Polyvinyl Chloride, is an engineered plastic polymer that is extremely versatile in all areas and industries, it is because of this that it is the third most widely produced synthetic plastic polymer in the world. PVC in the context of construction is mainly used in the manufacturing of pipes and corrugated roofing sheets. PVC is a sought-after material for its mechanical strength, lightweight nature and abrasion resistance.

Roof Pitch

Roof Pitch or Roof Slope is simply the steepness of a roof. Roof Pitches are measured in one of two ways, one by measuring the angle of the roof in degrees, the other slightly more complicated. The second way to calculate a Roof Pitch is to measure the number of inches it rises vertically for every 12 inches it extends horizontally. For example, a roof that rises 8 inches for every 12 inches of horizontal run has a 8/12 pitch, and if you wish, the angle of the pitch can be calculated from these measurements.

Rough Sawn

Rough Sawn Timber or Wood is the most basic form of the wood after felling. The timber is cut in to lengths with a circular saw and receives no further plane work, sanding or treatment. This leaves the sides and edges of the timber with a rough finish and texture. When you purchase Rough Sawn Timber and commence work with it, you can apply all of the treatment and work that comes with other forms of Timber such as Canadian Lumber Standard and Planed All Round, but these varieties are already finished and the work has already been done.

Screed

Screed is a paste material made by mixing sharp concreting sand and cement, which is then layered over concrete subfloor. Screed is mainly used to cover up under floor heating pipes and provide a smooth and level surface for the flooring boards to be placed on top of. It is suggested that bonded screeds should be applied in a layer that is at least 50mm thick, with unbonded screeds being recommended to be at least 70mm thick.

Shiplap

Once a popular design of board in the construction of ships, Shiplap is a board that is characterised by the grooves made in the board to make each of them slot together to create small gaps between each board. The difference between shiplap and traditional tongue and groove boards is the longer lip on the boards design, which provides an added practical benefit of helping protect against moisture and rainfall.

Stucco

Stucco is another name given to traditional Render. It is a construction material made of aggregates, binder and water to which is applied wet then dries to a dense solid. Stucco is traditionally used to create decorative patterns on walls and ceilings, often referred to as popcorn ceilings. Stucco can also be used for external building siding. However, it must be noted that if your home is in an area where the soil is high in clay, Stucco siding may not be the best choice due to its brittle nature.

Stud Wall

A Stud Wall is essentially a wall that provides no structural use in a building, it is just there as a way to partition rooms. Stud Walls are made by simply building a timber frame and bolting it to the floor, with possibly the addition of plasterboard. Stud Walls have increased in popularity over the years and are now common place in most modern homes.

Tongue & Groove

Tongue & Groove is a common method of making deliberate cuts and grooves in to boards to slot them together to create a cohesive and structurally sound panel. The Tongue & Groove design is often used in large surface area work such as flooring, panelling and cladding. It gets its name due to the fact that each board has a protruding tongue side and a receiving groove side.

Veneer

Wood Veneer refers to the process of taking very thin slices of wood, usually around 3mm thick and gluing it to a core panel such as particle board or MDF to mimic the appearance of solid wood. Choosing Veneer over solid wood has many benefits, including being easier to clean, resistance to splitting and warping and a much longer life.

Warping

When a piece of wood warps, the board will bend making it unusable in most projects, especially those that require a completely flat surface. Warping can be caused by a number of different factors, which are more likely to occur as the wood gets older. These factors can include exposure to stressors, uneven shrinkage and the wood drying up and therefore not being able to absorb moisture evenly. Warping can even occur during the storage process of the wood, so it is always advised to store the wood in the correct way.

WBP

WBP, or Weather & Boil Proof, is a grade applied to exterior plywood that states that the glue or resin holding the layers of wood in the board together will not break down under extreme weather conditions. Not just this, this grade also means that if needed, the plywood can withstand being submerged in boiling water.

We hope this glossary of key terms has expanded your knowledge on the jargon of DIY and construction. If you require any further information regarding any building materials, sizes and grades, our dedicated customer service team will be happy to assist you.