I was actually going to say with great difficulty . When I was serving my time I actually helped repair a tunnel with a skew back arch, in refractory brick work . Refactor brickwork is wear you lay firebricks (high heat resistant bricks) by spreading fire clay on the bricks like butter then rub the brick together so you get a Tight 3mm to 4mm & full joints ( no holes ) . The tunnel was used to take smoke from beehive kilns, underground to a tall chimney . We had numbered all the bricks and taken Polaroid snaps of the tunnel before we dismantled a section . Just as well as there was all shapes of bricks in it , would have been like a jigsaw puzzle with out a reference . Just After I served my time I worked on an tunnel at Carlisle shopping centre . It was designed so a fire engine could go through it , turned out the wrong size was given to the architect . Talk about tight !!! . The arch was a simple double rough ring arch normal bricks (not voussioirs bricks think dairylee triangles ) . As we got in to the swing of it we were really flying . Dead easy this arch building we thought. . The health and safety boffin had insisted on a solid plywood top to the arch centre , in case we dropped any thing . But traditional you use timber laths . laths are great you can gauge were you are by using the side of the lath and they have gaps between them so it is easy to pop underneath and look up and keep the brickwork nice and straight . The hard bit with arch building is the face side of the brick is hidden from you and on a elliptical rough ring arch you have to increase or decrease the thickness of the perp joint of mortar on the rear of the brick while keeping the face side at 10 mm . When the arch centre formwork was dropped. We could see a tiny bit of the brick work had a slight wave to the face . No one else noticed . It did look bloody impressive to me once pointed . But we were a bit deflated . Till we noticed another squad of bricklayers who were building an arch above a 4.5 m wide window in voussioirs . One side of the arch had started one course of bricks lower than the other side . Some plonker had forgotten to put the gods truth ( a stabila spirit level ) on to the bottom of the timber formwork to check it for level. . A simple mistake , but its not being past on to the next generation of bricklayers . NVQ ( not very qualified) bricklayers don't even learn how to build chimneys now a days .
