Screen Walls

In parts of the garden, you may find that a brick wall would form too solid a barrier, in which case you may decide that a screen wall of purpose-made, patterned concrete blocks may be more appropriate. Many different geometric and free-form patterns of screen wall blocks are available, such as squares, diamonds, leaves and stars.

Walls of this kind should be supported at each end and at 2.5 m (8 ft) intervals by piers built of hollow pilaster blocks, which are usually reinforced with iron rods set in the footing and filled with mortar or concrete. Despite this, screen walls are not strong, and you should seek professional advice if you want to build a wall higher than 2 m (6 ft).

Method

Place a course of blocks and pilasters alongside the prepared footing to position the supporting iron rods. Before the footing concrete sets, knock in the rods, leaving enough exposed to reach the middle of the highest pilaster.
Lay a 1 cm bed of mortar around the rod. Lower the pilaster onto the mortar, using a spirit level to ensure that it is level.
Fill the inside of the pilaster with concrete for reinforcement.
Lay a 1 cm mortar bed along the footing and the side edge of the first block. Position it into the pilaster.
Repeat at the other end of the section, so that you have laid one block at each end.
Align the intervening blocks by pushing pegs into the ground and stretching a string between them.
Position the next block, knocking it gently into place with the handle of a trowel.
Repeat this procedure along the row of blocks, checking the alignment regularly with a spirit level.
Start the second row by placing the pilasters and filling them with concrete as before.
Lay the second row of blocks using chicken wire embedded in the mortar to strengthen the bonding.
Repeat for subsequent rows until you have reached the desired height.
Mortar the pilaster caps and coping stones into position.
Finally, check levels, tidy up the pointing and square off the mortar at the base of the wall with a trowel.