UK Standard

BS EN 998-2 — Masonry Mortar

BS EN 998-2 — Specification for mortar for masonry. Masonry mortar

In short: BS EN 998-2 is the European standard for masonry mortar, classifying mortar by compressive-strength class from M1 to M20 (for example a 1:4 cement:sand mix is class M6).

What BS EN 998-2 covers

It governs designated masonry mortars used for bricklaying, blockwork and repointing, defining the strength class rather than just a volumetric ratio.

A 1:4 cement:building-sand mix is the standard M6 designation for general UK brickwork; 1:3 (M12) is used for engineering brick and exposed work.

Pre-1919 solid-wall buildings generally require a softer lime mortar (NHL) rather than a cement mortar to allow movement and breathability.

Common BS EN 998-2 mortar designations
Designation Cement:Sand (by volume) Typical use
M12 1:3 Engineering brick, exposed / below DPC
M6 1:4 General brickwork & blockwork (standard)
M4 1:5–1:6 Internal / sheltered blockwork

Apply this standard

Calculators that use BS EN 998-2

Mortar Mix Calculator
Sand and cement quantities for any mortar mix ratio and wall area.
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Brick & Block Calculator
Bricks or blocks required based on wall dimensions and bond pattern.
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Paving Slab Calculator
Slab count for any patio area, factoring in joint gaps and wastage.
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Official source: BSI Knowledge — BS EN 998-2. Figures on this page are a plain-English summary for estimating purposes — always refer to the published standard for compliance.