Construction glossary

An ASHRAE 34 safety class: low toxicity, lower flammability, e.g. R-32 and R-454B.

A classification of temperature/time conditions for plastic pipe systems; class 1 hot water 60°C, class 2 hot water 70°C.

Lightweight block with 70–80% porosity, steam-cured under pressure; thermally insulating and light.

Spreading a thin layer of adhesive on the back of the tile before setting it, to improve contact.

The load in newtons at which a tile breaks in the ISO 10545-4 bending test.

CO₂ reacting with lime in concrete, lowering its alkalinity; corrosion starts when pH at the steel falls below 9.

Cement-based adhesive mixed with water; C1 normal, C2 improved.

A statistical concrete strength value that the vast majority of results are expected to exceed.

Chlorinated PVC for hot and cold water up to 82°C per ASTM D2846.

A structural repair mortar under EN 1504-3 with compressive strength above 45 MPa and 2 N/mm² adhesion.

Galvanised sheet steel sections formed at room temperature for light wall and roof framing.

An intermediate layer improving adhesion of new concrete or mortar to old; Type I may dry first, Type II wet-on-wet (ASTM C1059).

The concrete thickness between the reinforcing steel and the element surface; protects steel from corrosion.

Characteristic cylinder strength 25 and cube strength 30 N/mm² at 28 days.

A membrane's ability to stay intact over a widening crack; minimum 0.75 mm in EN 14891.

Flexible cross-linked polyethylene pipes for hot and cold water.

Keeping concrete moist and protected so the cement reaction completes; at least 7 days for Type I/II (ACI 308R).

The ability of hardened adhesive to deform without debonding: S1 from 2.5 to under 5 mm, S2 ≥ 5 mm.

The fall of a horizontal drain; 2% for 2½ in and smaller, 1% for 3 to 6 in (IPC 704.1).

Tile formed by pressing granulated powder at high pressure.

Dynamic coefficient of friction; ANSI A326.3 requires ≥ 0.42 wet for level interior floors expected to get wet.

White salts carried by moisture to the surface of mortar or masonry; needs salt and moisture together.

Clay soil that swells when wet and shrinks when dry; covers about 37% of Saudi Arabia.

Tile formed by pushing a plastic paste through a die and cutting it to length.

Flooding a waterproofed surface for a set period to confirm there are no leaks before tiling.

A gas emitted from adhesives in some engineered panels; compliant panels in the US carry a TSCA Title VI label.

Glazed tile has a glass-like surface layer; unglazed tile has no coating.

The material filling joints between tiles; CG cementitious, RG resin (epoxy).

Improved cementitious grout with reduced water absorption and high abrasion resistance.

An enclosure's degree of protection against solids (first digit) and water (second digit) per IEC 60529.

Hollow foam blocks stacked and filled with reinforced concrete, with the foam remaining as insulation.

Two or more panes with a sealed space between; fog between the panes means the seal has failed.

A roof with XPS insulation above the waterproofing membrane, protecting it from sun, heat and damage.

Bacteria that multiply in water between 20 and 45°C and can cause pneumonia.

A height difference between the edges of two adjacent tiles.

A membrane brushed on under tiles in wet areas; classified in EN 14891 as CM, DM and RM.

A near-invisible coating on glass that reflects infrared and ultraviolet, reducing heat transfer.

Board of wood fibres pressed with adhesive; smooth for painting, sensitive to water unless moisture-resistant.

A breaker that protects a circuit from overload and short circuit.

Modified bitumen waterproofing membranes; SBS is more flexible, APP is usually torch-applied.

Gypsum board with reduced water absorption per EN 520 (H1 ≤ 5%). Moisture-resistant but not waterproof.

The share of adhesive contact with the tile back and substrate; 80% dry interior, 95% wet/exterior (ANSI A108.5).

A joint filled with flexible sealant to absorb expansion and contraction; missing joints are a main cause of tenting tiles.

The area of actual material in a block cross-section after excluding voids.

A scheme in which a solar owner receives credit for surplus electricity exported to the grid.

A pipe's nominal pressure in bar at 20°C.

Staggering tile rows; limited to 33% for tiles whose offset side exceeds 15 inches.

The maximum time after spreading adhesive within which tiles can be set and still bond; code E means ≥ 30 minutes.

Flat elements (walls, floors, roofs) made in a factory and assembled on site.

Surface cracks in fresh concrete when surface water evaporates faster than bleed water rises.

Polypropylene pipes for hot and cold water joined by heat fusion (ISO 15874).

Tile with water absorption of 0.5% or less (group BIa, or per ANSI A137.1).

A first coat that improves paint adhesion and evens out surface absorption, especially on filler and new surfaces.

The earthing conductor, coloured green/yellow exclusively.

Reflective aluminium foil next to an air space that reduces radiant heat; saves 8–12% of cooling costs.

Slip resistance rating with shoes on an oiled ramp; R13 is the highest.

Tile whose edges are machine-cut after firing to precise dimensions, allowing narrower joints.

A device combining MCB and RCD functions for a single circuit.

A device that trips when phase and neutral currents differ; protection for people.

A coastal salt flat that may collapse on wetting, is corrosive, and heaves as salts crystallise.

Routes where unprotected concealed cables may run: 150 mm at the ceiling and corners, and vertically/horizontally from switches and sockets.

A panel with two thin facings and an insulating core; plastic cores are combustible, rock wool is non-combustible.

A flexible, mould-resistant sealant for bath, basin and shower joints; 100% silicone can't be painted.

The unified Saudi standard for household plugs and sockets (230 V).

The movement a sealant tolerates: 12½, 25, 35, 50 and 100/50.

A measure of AC efficiency over the season; adopted by SASO 2663 instead of EER.

Separated extra-low voltage; what is allowed in bathroom zone 0.

Codes on tile boxes for consistent colour and size; don't mix different codes in the same area.

How glossy dry paint is: flat, matte, satin, gloss. Higher sheen cleans more easily and shows flaws more.

The share of solar energy passing through a window (0 to 1); lower is better in hot climates.

A device that diverts surge currents to earth and limits transient overvoltages from lightning and switching.

Sprayed expanding polyurethane insulation; the building must be vacated during spraying because of isocyanates.

Cement with a maximum C3A content of 5% for concrete exposed to sulphates in soil and water.

An ASTM C494 Type F or G admixture reducing mixing water by at least 12%.

Abrasion resistance rating of glazed tile surfaces from 0 to 5 per ISO 10545-7.

A polyamide strip separating the inner and outer parts of an aluminium frame to cut the heat path.

A material's ability to conduct heat (W/m·K); lower insulates better.

Thickness in metres divided by λ; higher is better.

A valve that blends hot and cold water to a safe temperature at the point of use.

Tile whose colour and pattern run through its full thickness.

A bend holding water (2–4 in deep) that keeps sewer gases out; a dry trap causes sewer smells.

A breaker's instantaneous trip range: B 3–5 ×, C 5–10 ×, D 10–20 × rated current.

Board with additives improving cohesion in fire; fire resistance belongs to the whole tested system, not the board alone.

The heat transmitted through a building element; SBC 602 sets maximum values by climate zone.

Unplasticised PVC; its pressure pipes are for cold water (ISO 1452), and it is widely used for drainage.

A pipe that balances pressure in the drainage network and protects trap seals.

Compounds that evaporate from paints, solvents and adhesives into indoor air; the EU caps their content in decorative paints.

3D units made in a factory with floor, walls, ceiling and some finishes, then installed on site.

The increase in a tile's weight after saturation compared with its dry weight, as a percentage. The basis of tile classification.

A loud bang in pipes when valves close quickly; treated with an arrestor complying with ASSE 1010.

The stress at which steel starts to deform permanently; 420 MPa for Grade 60.