A considered response to structural movement and damage to the interior of St Stephen’s Church, Westbourne Park, London W2

St Stephen’s Church, Westbourne Park, London had suffered extensive structural movement and cracking to the interior over a long period. The source of the problem was not sufficiently understood or adequately addressed by previous repairs in 1990. Careful observation, investigation and analysis concluded that the primary source of the problem was lateral spread of the roof trusses. This action, combined with the very thin mortar joints in the internal stonework, had led to spalling of the stone and horizontal cracks in the clerestory walls of the nave. Repairs were specified to address these issues, approval sought through the process of ecclesiastical exemption, and robust remedial and preventative works carried out. This paper seeks to explain the thinking behind the process of analysis, design and specification of these works, and (while acknowledging previous works) examines the problems starting from first principles. It is intended to give the reader guidance on the assessment of unusual or long-standing structural problems and the confidence, when necessary, to propose and execute what might otherwise be considered radical interventions in a historic public building.