The technique of applying colour-fast oxide-based pigments in a potassium-silicate medium to give a permanent tint to the surface of brick masonry has been used with success for about 40 years.
Experience has shown that such tinting is a permanent modification of surface colour and the treatment has no adverse effects on the durability or other performance attributes of the masonry.
Most often the reason for its use is to rectify a mismatching of bricks and/or mortar, or to correct colour banding or a patchy appearance resulting from a failure to blend bricks adequately during laying.
Designers have also used this technique to create a particular colouration that could not be achieved by the selection of bricks alone. For example, when a particular colour is unobtainable, bricks of the same size and textural character can be substituted and subsequently tinted (figs 1, 2 and 3).
One example already given in this issue (page 12) is the diaper patterns in the brickwork of the new houses on the Ashwood Place development in Woking. Here tinting was used to enhance the blackness of the headers forming the diamond patterns to match more closely those of the original house (fig 4).
Tinting has also been used to create contrasts in the bond pattern of brickwork after completion. For example, pictogram motifs can be picked out by tinting bricks to contrast with the walling at large. This option probably offers a more economic alternative to building the feature work with contrasting bricks.
Yet another exponent is the sculptor Richard Kindersley, who frequently enhances form and line of his carvings in brickwork with complementary or contrasting tints (fig 5). As Kindersley says (Brick Bulletin, Winter 1999): 'These dyes have always to be used with restraint as the work can easily be spoiled with too harsh a treatment.'
This is true of all tinting applications and for this reason the work should only be entrusted to specialist contractors with the appropriate knowledge, experience and skill, rather than to a general building contractor.
British Standards exist for the pigments used for tinting, but not for the tinting procedures. There are only a few specialists offering tinting services.
The BDA and its members can provide contact details for companies that have been known to us for several years. However, the BDA does not endorse the work of individual companies or craftsmen providing services in the construction industry.