The St Astier Blog – all the latest news on our specialist repair schemes and related activities brought to you with a hefty dose of insight into the inner workings of our humble company.
Structural Repairs at the Sunderland Empire
St Astier is currently undertaking a programme of masonry reinforcement works in order to reinstate the structural integrity of Sunderland's Empire Theatre. Opened by the famous male impersonator Vesta Tilley in 1907, the theatre is one the only venue in the region capable of hosting large scale West-End productions.
The main entrance to the Empire Theatre is through a handsome 90ft sandstone rotunda with domed roof on High Street West which runs through the heart of the city centre. The four-tier auditorium and stage area is housed in a more modest part of the building constructed using traditional red brick masonry. It is this section of the theatre, just visible with scaffold in the photo above, which is subject to repair.
A high level structural survey uncovered a number of cracks in the masonry which were up to 50mm wide in places. It was believed that weathering, accelerated by the incorporation of black ash mortar, and the deterioration of built-in ferrous elements had led to the severe cracking. Heavy duty window bars had contributed to cracks in the masonry and elsewhere, corroded hollow steel used for reinforcement in the original construction had caused some of the cast-in-situ lintels, which continue for the full length of the walls, to fail.
The seven week programme of works involves the installation of approximately 600m of stainless steel reinforcement under the strict guidance of Helifix. Alongside the introduction of CemTies and Helibeam to provide lateral restraint, the repair specification also calls for the installation of 12mm Sock Anchors in 1500mm and 2000mm lengths to reinstate structural integrity. Each of the defective lintels is being replaced with pre-cast units which have been manufactured in-house. Extensive structural re-pointing is also being undertaken using Parex Easipoint cement-free Heritage Mortar.
The theatre’s busy production schedule is not effected by the works.