BTEB Masonry key terms

The trade of building structures by laying individual units such as brick, block, or stone in mortar or with other fixing methods. It covers walls, piers, arches, and finishes.

A workable mixture of cementitious binder, fine aggregate, and water that hardens to bond masonry units together and fill irregularities between them. It also seals joints against weather.

The horizontal layer of mortar on which a masonry unit is laid. Its thickness is normally kept uniform, commonly around 10 mm, to spread load and keep courses level.

The vertical mortar joints separating adjacent units in the same course. They are filled and finished neatly because open perpends let water into the wall and weaken the bond.

A continuous horizontal layer of masonry units of the same height, laid along a wall. Courses are kept level and plumb so the wall carries load evenly and looks regular.

The planned arrangement of masonry units in a wall so that vertical joints in one course do not line up with those in the course above. Bond spreads load and strengthens the wall.

A bond in which every unit in a course is laid lengthwise along the wall face, with each course offset by half a unit. It suits single-leaf walls and is also called running bond.

A bond made of alternating courses of stretchers and headers. It is strong and commonly used for walls one brick or more thick, but it produces a plainer appearance than Flemish bond.

A bond in which each course alternates stretchers and headers, giving a decorative face pattern. It is used mainly where appearance matters, such as fair-faced walls.

A masonry unit laid lengthwise along the face of the wall so that its long side is visible. Stretchers form the main face pattern in bonds such as stretcher bond.

A masonry unit laid so that its shorter end shows on the wall face and it ties through the wall thickness. Headers link the two leaves of a thick wall together.

A cut piece of masonry unit, about half the length of a full unit, used to close the end of a course or to start a bond correctly. Cutting must be square and clean.

The unit or cut piece placed at the end of a course to finish it neatly and keep the bond correct. A queen closure is a brick cut to about three-quarters of its length.

The corner stones or units of a wall, laid in a regular alternating pattern to form a strong, plumb corner that guides the rest of the masonry as it rises.

The height of a masonry course, including the bed joint, used to set out and keep courses consistent. Gauge is often marked on a storey rod for repeated measuring.

A straight timber or metal batten marked with course heights, openings, and sill levels for a storey. It is used to set out and check masonry quickly and consistently.

Exactly vertical, checked with a spirit level or plumb rule. Masonry must be kept plumb so that walls stand straight and carry load as designed.

Exactly horizontal, or the tool or check used to confirm a surface is horizontal. Courses and bed joints are checked level to keep the wall true and even.

A straight-edged tool containing bubble vials that shows whether a surface is level or plumb. The mason uses it constantly to check courses, corners, and finished faces.

A taut string held between two pins or blocks at the ends of a course, giving the mason a straight guide for laying units. It keeps the face line straight and even.

A flat steel blade with a handle, used by masons to pick up and spread mortar, tap units into place, and trim joints. Its shape and balance affect the quality of the work.

A flat board, often with a raised edge, on which mortar is placed and kept workable while the mason lays units. It is kept clean so set mortar does not contaminate fresh mix.

A machine or container used to blend sand, binder, and water into a uniform mortar. Correct mixing time and proportions give consistent strength and workability.

The process of filling and finishing the exposed face of mortar joints after laying. It improves weather resistance and appearance and may replace raking out and repointing later.

Forming the visible surface of mortar joints, for example flush, recessed, or weather-struck. The chosen profile affects water shedding and the look of the finished wall.

Keeping freshly built masonry moist and protected for a period so the mortar gains strength and does not dry out too fast. Curing improves durability and reduces cracking.

A white powdery deposit of soluble salts on the surface of masonry, carried there by water and left behind as it evaporates. It is usually brushed off and prevented by keeping the wall dry.

A continuous water-resistant layer built into a wall near ground level or above openings to stop moisture rising or crossing into the building. It must not be bridged by mortar.

A wall of two leaves separated by a gap, tied together with wall ties. The cavity keeps rain out and improves insulation, and it must be kept clear of mortar droppings.

A metal fastener built into both leaves of a cavity wall to tie them together and resist wind load. Ties are spaced to the design and must slope slightly to shed water.

A strip of water-resistant material, usually metal, built in at a junction such as a roof or parapet to stop water entering the masonry. It is lapped and dressed to shed water.

A small opening left in a mortar joint above flashing or at the base of a cavity so trapped water can drain out. It must be kept clear of mortar and debris.

A horizontal structural member spanning an opening in a wall to carry the masonry above it. It may be of steel, concrete, timber, or reinforced masonry and needs adequate bearing.

The length of wall or support on which a structural member such as a lintel rests. Insufficient bearing can cause cracking or collapse, so it must meet the design.

A curved structural form that spans an opening by transferring load through compression along its curve to the supports. Types include semicircular, segmental, and flat arches.

One of the wedge-shaped units forming the curve of an arch. The central one, the keystone, is often emphasised, and all must be laid to the correct line and joint width.

A vertical mass of masonry, thicker than the wall it supports, built to carry concentrated load or stiffen a long wall. Piers are often bonded into the wall they strengthen.

The side face of an opening in a wall, between the outer wall face and the frame or inner face. Reveals are built plumb and square so frames and finishes fit properly.

Gear worn to reduce injury risk on site, such as a hard hat, safety boots, gloves, eye protection, and hearing protection. It is the last line of defence after other controls.

A temporary working platform erected to give masons safe access to walls at height. It must be stable, fully boarded, and fitted with guard rails and toe boards.

Lifting, carrying, and moving loads by hand. Masons reduce injury by assessing loads, using correct technique, and using mechanical aids for heavy units.