After a long period of dealing with all site issues remotely, to reduce the risks associated with Covid 19, we finally visited site.
It was wonderful to see the progress made, with Morgan Sindall having benefitted from the great weather to make good progress. Accessing the site from the new contractors’ car park, the immediate improvement proportions due to the removal of the 1980’s ‘umbrella’ roof was clear, even before the 1943 brickwork parapet is lowered.
Once on site the focus was on reviewing the suggested repointing scope, marked up in chalk on the Power Hall west wall by Concrete Renovation Ltd, the heritage brickwork subcontractor. We clarified that all historic pointing was to be physically examined, brick joint by brick joint, and where pointing was in good functional order, it was to be left undisturbed. We also looked at and discussed their initial trials of lime / sand / grit mortar mixes. This led to the unsurprising conclusion that the 1928 brickwork had used different sands than the 1936 brickwork, and the decision made to adopt two different sand sources to achieve a good visual match for each. This was the first trial yellower sand and St. Anstier NHL lime mix trialled on a Power Hall pier:
From the top lift of scaffold we also reviewed the condition of the original Portland Stone coping stones. A bit battered and bruised, but most are essentially sound, and we discussed the details of their rebedding, isolated repairs, and repointing.
Ascending the vertiginous scaffold stair to the top of the Transmission Block, the extent of progress is clear, with the bulk earthworks complete, car parks and MUGA formed, and the new blocks’ footings well underway.
Looking down, the porthole windows of the Power Hall Gallery are now re-opened, revealing the striking character of the entrance courtyard elevation, at the heart of the future school.
On the roof the thick 1943 concrete slab is being slowly demolished, over a birdcage scaffold crash deck filling the 12m high former Transmission Hall. Underneath that, in the former Valve Hall at ground floor, the piles for the new structure are being prepared for casting the ground beams. These piled foundations will ensure that the loads from the additional floors and roof of the school have no impact on the historic structure.
Last, but not least, it was gratifying to see the first of the schools six new steel frames being erected, by MQM at the north end of the Power Hall. This will support the dining hall mezzanine and plant room levels over the school kitchen.