Step 8: Lay the bricks
Move the stringline for the outer face of the wall on the hurdles (refer Fig. 4), then lay the bricks out dry for the first course along the foundation to work out their correct placement. Now lift them to one side and set this course accurately to the stringline by laying a mortar bed. Using a trowel. To lay a bed, chop off a section of mortar with the trowel that’s about the same size as it. Separate it from the bulk of the mortar with a clean slicing action and shape it into a curve, as near to a sausage shape as possible (Fig. 7). Sweep the trowel underneath to lift it from the mortar board in one go. Slide the trowel sharply backwards to lay the mortar in a sausage shape, and use the tip in a stepping action down the middle to spread it out. Lay enough for at least two bricks at a time. Lay the first brick in place and tap down with the trowel handle until the top outer corner of the brick rests against the stringline. The mortar should make a I0mm joint.
For the next brick, butter one end to create the vertical join before you lay it (Fig. 8). Hold the brick in one hand and scrape on mortar with your trowel to one ‘perp’ end. Place the buttered end against the first brick to form a vertical joint I0mm thick and firm down with the trowel handle, again so the top outer edge for the bricks rests against the stringline. Repeat this for the next four or five bricks, still following the stringline. Test with your spirit level that the bricks are truly horizontal. Carefully scrape off excess mortar with your trowel. When the first course is laid, you can dispense with the hurdle line and use bricklayer’s pins and line, gauge rod and spirit level instead.
Each brick for all following courses should straddle two on the last course, so you’ll probably have to cut bricks to fit at the ends of alternative courses. Mark a cutting line on each face of the brick and nick the line all around with your bolster and mash hammer. Place the brick bottom on grass or sand, put the bolster on the nicked line, give it a sharp blow and the brick should cleanly break along the line (Fig. 9).
The corners should now be ‘racked’ – that is, built up by several courses (Fig. I0). With each new course, check that the corners are rising correctly with the gauge rod (Fig I0). With a spirit level, check that each brick you lay is level and that the brick faces are both vertical and plumb. To lay the second course, tap flat bricklayer’s pins into a vertical mortar joint at one end of the wall. Stretch a stringline from these pins to the other end of the wall, then secure the line taut with a second pin so that it’s in line with the top edge of the next course. Lay the bricks in the middle to this line, testing each course for level and plumbness. Move the pins and line up to each course until all courses are filled between the racked corners. When the last course is complete, build up the ends again and fill in the middle until you reach the planned height.