BTEB Masonry flashcards
BTEB Masonry · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Nominal vs actual brick
- Nominal size includes the mortar joint, actual size does not. A modular brick is 3-5/8 in high and 7-5/8 in long actual, but 4 in by 8 in nominal with a 3/8 in joint.
- Modular brick module
- The repeating vertical dimension of one brick plus one joint, about 2-2/3 in. Multiplying by courses gives wall heights, and four and a half courses equal 12 in.
- Type M mortar
- Highest-strength mortar mix, roughly 1 part portland cement to 1/4 part lime to 3 to 3-1/2 parts sand. Used for heavy loads, below grade, and masonry in contact with earth.
- Type S mortar
- Medium-high strength mortar, about 1 part portland cement to 1/2 part lime to 4-1/2 parts sand. Common where moderate compressive strength and good tensile bond for lateral loads are needed.
- Type N mortar
- General-purpose mortar, about 1 part portland cement to 1 part lime to 6 parts sand. Preferred for exposed above-grade walls because it is workable and tolerates slight movement.
- Type O mortar
- Lowest-strength mortar, about 1 part portland cement to 2 parts lime to 8 to 9 parts sand. Limited to interior non-load-bearing partitions and repointing of soft historic brick.
- Concrete block actual size
- A nominal 8 by 8 by 16 in block measures 7-5/8 by 7-5/8 by 15-5/8 in. The difference is the 3/8 in joint, so three courses equal 24 in exactly.
- Running bond
- Bond pattern in which each course is offset half a unit from the course below, so vertical joints do not align. It is the most common pattern for brick veneer and single-wythe walls.
- Flemish bond
- Bond pattern with alternating stretcher and header units in every course. It produces strong, decorative walls but is slower to lay than running bond.
- English bond
- Bond pattern alternating one full course of stretchers with one full course of headers. Strong and traditional, often used for thick load-bearing brick walls.
- Stack bond
- All units align directly above one another with continuous vertical joints. It carries little load without reinforcement and is used mainly for decorative veneer with joint reinforcement.
- Header course
- A course of bricks laid with their short ends facing the wall face, tying the wall wythes together. Headers are often placed every sixth course in English bond work.
- Wall tie spacing
- Metal ties connect veneer to backing. Typical rule is one tie per 2-2/3 square feet of wall, spaced no more than 24 in horizontally and 16 in vertically.
- Through-wall flashing
- Impervious material placed across the wall thickness to stop water. It needs a drip edge outside, end laps of at least 6 in, and a turned-up leg behind the veneer.
- Weep holes
- Openings left in the mortar joint just above flashing so water in the cavity can drain out. Spaced typically 16 to 24 in apart and kept clear of mortar droppings.
- Cavity wall
- Wall with two masonry wythes separated by an air space, tied together with metal ties. The cavity drains water and adds insulation space, and it must be kept clear.
- Mortar joint tooling
- Compacting the joint surface with a jointer after the mortar is thumbprint hard. Tooling seals the surface and forms a concave or V shape that sheds water.
- Bed joint
- The horizontal layer of mortar on which a masonry unit is laid. Bed joints carry compressive load and their thickness is normally held to about 3/8 in.
- Head joint
- The vertical mortar joint between the ends of adjacent masonry units. It must be filled fully, since voids let water penetrate the wall.
- Course height calculation
- Divide wall height by the module to get course count. For example, a 96 in wall with a 2-2/3 in brick module needs 36 courses, plus allowance for bond beam or lintel.
- Block bond beam
- A course of block with the webs removed and a continuous grout and rebar core. It acts as a horizontal beam over openings and ties the wall together.
- Lintel
- A horizontal member spanning an opening to carry masonry above it. It must bear at least 4 in on each side and be flashed above if exposed.
- Masonry grout
- A high-slump cementitious mix poured into reinforced cores and collar joints. It must flow without segregation and is usually placed in lifts of limited height.
- Efflorescence
- A white salt deposit on masonry surfaces caused by water moving through the wall and evaporating. It signals moisture entry, so the source of water must be corrected.
- Compressive strength of brick
- Brick grades are set by compressive strength and absorption. Higher strength and lower absorption suit severe weathering and load-bearing use; the unit strength exceeds the mortar strength.
- Prism test
- A small assembly of units and mortar tested in compression to estimate masonry strength. It reflects real joint behavior better than testing units alone.
- Sill and flashing detail
- A sloped sill sheds water outward and sits on flashing that turns up at the ends. End dams stop water from running sideways into the wall.
- Expansion joint in masonry
- A vertical gap that lets a masonry wall expand and contract without cracking. It runs through the full wall thickness and is sealed with a flexible backer and sealant.
- Control joint
- A deliberate vertical break in a masonry or concrete wall that controls where cracking occurs. It is sealed against water and placed at regular intervals and at corners.
- Anchor bolt embedment
- Bolts tying framing to masonry must be set into grouted or solid masonry with specified embedment. They are placed in cores or drilled and anchored, never in unfilled hollow block.
- Laying to a line
- A mason stretches a line between corner leads and lays units to it. The line sets the face plane and course height, so it must be checked for sag and level.
- Racking back
- Stepping the end of a wall back in a staircase pattern so fresh masonry is not left as a tall unsupported toothed end. It lets work resume with a sound bond.