Masonry Inspection

In accordance with EN 1996-2 Section 3, masonry units must comply with EN 771 (clay, calcium silicate, concrete or natural stone). Mortar must comply with EN 998-2 — prescribed (by volume/mass) or designed (by compressive strength, e.g. M5, M10, M15). The mortar class must match the project specifications. DTU 20.1 specifies execution rules and additional requirements for the French market.

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

2. Verify that unit compressive strength meets design requirements

3. Check that the mortar class (M2.5, M5, M10, M15) matches specifications

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

5. For designed mortar, check compressive strength test results

- Incorrect unit type or strength class delivered

- Mortar too weak — incorrect proportions or excess water

- Units not wetted before laying (high absorption units)

- Factory mortar expired or incorrectly mixed on site

In accordance with EN 1996-2 Section 3.6, walls must be built with correct bonding pattern, perpend and bed joints fully filled (for load-bearing walls), and within plumbness tolerances. Cavity wall ties per EN 845-1 must be installed at the specified spacing (typically 2.5/m2 minimum). Bed joint thickness is typically 10-15 mm. DTU 20.1 defines specific execution rules.

1. Check wall plumbness with plumb bob — tolerance per EN 1996-2 (typically +/-20 mm per storey)

2. Verify correct bonding pattern — staggered perpend joints between courses

3. Check bed joint thickness for consistency (10-15 mm typical)

4. Verify perpend joints are filled in load-bearing walls

5. Check that cavity wall ties are installed at correct spacing and sloped outward

- Walls out of plumb or misaligned

- Unfilled perpend joints reducing wall strength

- Bed joints too thick or uneven — reduced compressive strength

- Wall ties missing or incorrectly spaced in cavity walls

In accordance with EN 1996-2, movement joints must be provided to absorb thermal and hygroscopic movements. Typical spacing: 12 m for clay brick masonry, 6 m for concrete/calcium silicate. Damp proof courses (capillary barriers) must be installed per EN 1996-2 Section 3.4, at a minimum of 150 mm above external ground level. DTU 20.1 specifies provisions for waterproof courses and capillary barriers.

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

2. Ensure joints are continuous through the full wall thickness

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

4. Check that the barrier material is intact and overlaps are sealed

5. Inspect cavity trays above openings and at level changes

- Missing movement joints causing cracking in long walls

- Damp proof course bridged by mortar droppings or render

- Cavity trays missing or not extending to weep holes

- Movement joints filled with rigid mortar instead of flexible sealant