Last night I decided to crack on with the brick arch so we can block up the doorway properly and get a little security back in to the house.
I started off by tracing the curve of the existing upper arch bricks (which have loosened a little more), and cutting a 110mm smaller radius in to two sheets of 18mm ply.
I nailed those two sheets to a block so ended up with a curve that you can balance a brick on.
It was then a case of holding it in place and mounting it to two uprights to keep it in place.
I chose 9 clean but old (reclaimed from a now-removed chimney stack) bricks and placed them in to the former to check for size and fit. It also tested the former for bearing the weight of the bricks whilst they dried.
I gave the existing arch, and the new bricks a good soak in water to stop them drying out my NHL5 lime mix, and then set about the task of 'mucking them in' using that lime.
It was a particular pain of a job, and the last brick had to be persuaded in to place with a rubber mallet.
The new arch was allowed to dry for 15 hours so the lime had a chance to harden (but not yet completely go off). Then I slowly relaxed the support from the wooden former to see if anything was going to slip.
It held fast, and is now slowly drying.