Masonry Inspection

According to NP EN 1996-2 Section 3, masonry units must comply with EN 771 (clay bricks, calcium silicate, concrete or natural stone). Mortar must comply with EN 998-2 — prescribed (by volume/weight) or designed (by compressive strength, e.g. M5, M10, M15). The mortar class must match the design specification.

1. Check that masonry units have CE marking and comply with the relevant part of EN 771

2. Confirm that the compressive strength of units matches the design requirements

3. Verify that the mortar class (M2.5, M5, M10, M15) matches the specification

4. For prescribed mortar, check the mix proportions (cement:lime:sand ratios)

5. For designed mortar, check the compressive strength test results

- Wrong unit type or strength class delivered

- Mortar too weak — incorrect mix proportions or excess water

- Units not wetted before laying (high-absorption units)

- Pre-batched mortar past its shelf life or incorrectly mixed on site

According to NP EN 1996-2 Section 3.6, walls must be built with the correct bond pattern, with vertical and horizontal joints fully filled (in structural walls) and within verticality tolerances. Wall ties in cavity walls according to EN 845-1 must be at the specified spacing (typically minimum 2.5/m2). Horizontal joint thickness is typically 10–15 mm.

1. Check wall verticality with a plumb line — tolerance according to NP EN 1996-2 (typically +/-20 mm per storey)

2. Confirm that the bond pattern is correct — perpend joints staggered per course

3. Check that horizontal joint thickness is consistent (10–15 mm typical)

4. Confirm that perpend joints are filled in structural walls

5. Check that cavity wall ties are installed at the correct spacing and inclination

- Walls out of plumb or misaligned

- Perpend joints not filled reducing wall strength

- Horizontal joints too thick or variable — reduction in compressive strength

- Wall ties missing or at incorrect spacing in cavity walls

According to NP EN 1996-2, movement joints must be provided to accommodate thermal and hygroscopic movements. Typical spacing: 12 m for clay brick masonry, 6 m for concrete/calcium silicate. Damp-proof courses (DPC) must be installed according to EN 1996-2 Section 3.4, at a minimum of 150 mm above external ground level. The RGEU also establishes foundation waterproofing requirements.

1. Check that movement joints are at the correct spacing for the unit type

2. Confirm that joints are continuous through the full wall thickness

3. Verify that the DPC is installed at the correct level (>=150 mm above ground)

4. Confirm that the DPC material is intact and laps are sealed

5. Inspect cavity trays above openings and at changes of level

- Missing movement joints causing cracking in long walls

- DPC bridged by mortar droppings or render

- Cavity trays missing or not extending to weepholes

- Movement joints filled with rigid mortar instead of flexible sealant