Limitations. This report is limited to the elements of structure described. Building services, timber decay, damp penetration, contamination and asbestos are specialist matters and are outside its scope unless expressly stated. Hidden or inaccessible parts of the structure were not inspected and cannot be guaranteed free from defect.

This report is confidential to Weir Street Developments Ltd and is provided for the purpose described in the introduction. Report Kit 360 accepts no responsibility to any third party who relies on it, in whole or in part, without our prior written agreement. Where our report refers to information supplied by others we have assumed it to be accurate unless stated otherwise.

Weir Street Developments Ltd asked us to inspect cracking in the north wall of the former mill warehouse before its conversion to apartments. The three-storey building (about 1885) is of solid brick load-bearing walls with timber floors on cast-iron columns. A stepped crack up to 6 mm wide (BRE category 3) runs from the ground-floor window at grid C to the parapet, with finer diagonal cracks at grid D. The pattern, the taper (wider at the top) and the position over the culverted mill race indicate differential settlement of the north wall at its western end, probably long-standing but recently reactivated by leakage from the culvert. The wall is stable at present. We recommend a six-month programme of crack monitoring, a CCTV survey of the culvert, trial pits to confirm the foundation, and, depending on the results, local underpinning and stitching of the cracks before conversion.

The warehouse was built around 1885 for the adjoining cotton mill and used for storage until 2019. A previous condition report (2021) noted hairline cracking at grid C. The client's architect reported that the crack had widened during the winter of 2025 to 2026, which prompted this inspection.

Loads from the timber floors are carried by cast-iron columns on a 3.6 m grid and by the external walls, which are 450 mm to 560 mm solid brick. The roof is a timber queen-post structure spanning between the north and south walls. Foundations are unknown; brick footings on clay are assumed. There are no movement joints. The mill race passes beneath the north-west corner in a brick culvert.

1. The north elevation was inspected from ground level and from a cherry picker; the internal face was inspected at ground and first floor. 2. Crack C1 runs in a stepped pattern through the bed and perpend joints from the sill of window N3 to the parapet, 6 mm wide at the top tapering to 2 mm at the sill; the brickwork is fractured through in places. 3. Crack C2 is a diagonal crack 2 mm wide above window N4 at grid D, following the line of an old arch repair. 4. Cracks C3 and C4 are hairline cracks in the internal plaster at first floor directly behind C1. 5. The parapet coping is displaced 10 mm at grid C and the wall tie exposed there is heavily corroded. 6. The timber floor bearings at grid B/2 and C/2 are sound; no distortion of the floor was measured. 7. Surface water from the yard discharges towards the culvert inlet, which is partly blocked.

The crack pattern (stepped, tapering, wider at the top, located over the culvert) is characteristic of differential settlement at the north-west corner rather than thermal movement or lintel failure. The reactivation in winter is consistent with softening of the clay by leakage from the culvert, which is partly blocked and overflowing at the inlet. Category 3 damage is serviceability rather than stability, but continued movement could affect the stability of the parapet and the window heads. Corrosion of the wall ties at the parapet is a separate, age-related defect.

Immediate: fence off the pavement below the parapet at grid C and remove the loose coping. Within one month: CCTV survey of the culvert and clear the inlet; install three tell-tales and take monthly readings for six months. Within three months: two trial pits at grid C to confirm the foundation and soil. Before conversion: subject to monitoring, local underpinning at grids B to D (about 9 m), helical-bar stitching of cracks C1 and C2, replacement of the parapet ties and repointing. A structural engineer should review the monitoring results before the conversion design is finalised.

Bearing pressure check on the north wall footing: characteristic loads from the roof, two timber floors and the wall self-weight to BS EN 1991-1-1, assumed 900 mm wide brick footing, presumed bearing resistance of 100 kN/m² for firm clay.