Though a garden wall is best left to gather lichen and become mellow with age, the wall of a house may in time come to look disreputable. A periodic scrub-down with clear water will help to keep bricks bright; and if moss collects it can be killed with a proprietary fungicide, or with ordinary household bleach diluted with about four parts of water. Leave for a day or two and then wash off with clear water.
You can re-stain bricks with venetian red or red ochre mixed with petrifying liquid. This will not last long. A brick dye which has silicone waterproof solution added should last for two years. The life of a brick and tile paint is very considerably longer. The snag is that it gives a wall rather an artificial appearance; and additional labour is involved in picking out the pointing in either white, black or grey. Clean the wall first with water and a stiff brush and remove all mossy deposits with fungicide or bleach.
A brick that has spalled badly can be refaced by chipping off the surface in situ and bonding in a slip brick cut to the right thickness, allowing for a bed of mortar mixed with a PVA adhesive.If it shows up too much, tone it down by brushing with creosote diluted with paraffin.
Brightening up a Dark Room
Where a room in your house — say a kitchen — is overshadowed by a high wall or by a neighbour’s house, light can be reflected by painting the wall in white masonry or emulsion paint. Permission from the owner of the adjoining property will have to be sought first of course.
If you are using emulsion, all that is needed after the wall has been brushed down is to give it a coat thinned with the same quantity of water. Follow with a normal coat thinned as directed on the container label. Repainting every four or five years will be a simple matter. Use a large nylon brush, which is not only cheaper than one made of bristles but will wear better with friction against a rough surface.
You can build a wall more quickly by using building blocks instead of bricks. They are not easy to handle because mostly they are twice as long and three times as high as a brick (and are of various thicknesses to suit different types of structure). They are light in weight, however, and as each block is the equivalent of six bricks you will see the time they save. They can be shaped with a cold chisel more easily than bricks and can be cut with a hand saw. Screws grip them without the necessity for plugging and they can be surface-rendered or painted with an outdoor grade of emulsion (one thin coat followed by a normal one).