On the second Tuesday of June the temporary roof came off the kiln hall, and for the first time since 1961 the building stood open to the sky. It will not remain so for long — the Penrhyn slate begins going on in the second week of July — but for a few weeks the tops of the four calcining flues are visible from the towpath, and we would encourage anyone passing to look up.
The structural retention is complete. The 1864 walls now carry their load through a steel cradle threaded inside them over the winter, which means the brick is no longer working alone for the first time in a century and a half. Our engineers describe the arrangement as a hand under an elbow rather than a crutch: the wall does what it has always done, with something patient behind it.
The numbers, for those who like them: 340 linear metres of repointing finished on the north elevation, in a lime mortar matched by eye and then by analysis to the original; 11,200 bricks recovered from the fallen western range, cleaned by hand and stacked for the repairs; four flues surveyed by drone and found sounder than anyone predicted.
In the new wing, the concrete frame reached level four in May and will top out in August. The two buildings are close enough now that you can stand in the gap between them — the gap that will become the entrance court — and understand the whole composition for the first time. It is the drawing, at full size.
Next: slate through July and August, glazing from September. The hopper windows for the kiln hall — galvanised steel, fabricated in Sheffield — are in production now, and the first units arrive on site in the early autumn. Watertight is programmed for the turn of the year, and nothing in the past six months has given us a reason to doubt it. We will report again when the first window goes in.