1 To build a ringed arch above an existing opening, first measure the distance across the opening and find its mid-point

2 From this point, extend a line upwards and draw a large semi­circle across the brickwork to mark the underside of the arch

3 Measure and extend this circle by a further amount so that you can cut away enough bricks to build the arch without being cramped

4 Use a hammer and bolster to cutaway the brickwork. Some openings have a piece of reinforced steel which needs to be removed

5 Continue upwards carefully, removing one brick at a time, until a large enough area has been cleared to start building

6 Make the sides of the former from 15mm plywood. First draw/a line the same size as the opening across the bottom of the sheet

7 Extend a piece of string from the mid-point of the line and tie a pencil to its top end. Use this to mark the two former sides

8 Cut carefully around the marked-out line. You can use a fretsaw although a powered jig saw makes the job a great deal easier

9 Cut a piece of timber to make up the bottom of the former and nail the two side pieces to it using galvanized nails

10 Then pin a piece of hardboard or thin plywood across the top of the former. Try to keep it level with the two side pieces

11 To support the former, fix a length of 50mm square timber to each side of the soffit using partly-driven masonry nails

12 Then lay a piece of flat plywood almost as wide as the soffit across the tops of the side bearers to complete the frame

13 To help you adjust the position of' the former, cut four folding wedges and position them in pairs underneath each end

14 Then check that the former is correctly positioned and in line with the existing wall surface using a straightedge and spirit level

15 Start at the bottom of the arch, building each side at the same pace. The bricks can be set either on edge or on end, according to plan

16 Try to make neat, wedge-shaped joints between each brick by laying more mortar at one end than at the other before positioning them

17 A line stretched up from the striking point ensures that each brick is correctly placed and facing inwards towards the centre

18 You can rebuild the brickwork around the arch as you progress or leave this until the whole arch has been completed

19 Point the brickwork on and 0 around the arch carefully. Then rake a soft brush across the whole area to help it to blend in

20 Leave the mortar to set for around three to four days before carefully knocking out the wedges and removing the former