T
raditional brick has enjoyed a renaissance with building designers in recent years. Its durability and excellent fire resistance have found favour with architects in search of a material with sustainable credentials and aesthetic potential.
Coloured mortar has helped accelerate brick’s rediscovery. Technological advances mean that as well as being an exceptional bonding agent, mortar’s increasing palette range can showcase traditional brick buildings in a whole new light.
Coloured mortar’s aesthetic benefits ensure buildings stay looking good for longer, making it a go-to solution for property owners in search of style and substance. As a critical building material, mortar’s merits are primarily judged on its strength. However, its ability to make brickwork stand out should not be underplayed. Buildings bearing a smart, attractive appearance reflect well on occupants and the environment, adding to their market value.
Mortars can be pigmented to produce a vast array of colours and tones to enhance or match the appointed masonry. The factory-produced process ensures consistency of colour regardless of batch requirement. For quality purposes, pigments should conform to the BS EN 12878(1) standard.
COLOUR PRODUCTION
The majority of pigments used to colour mortar are based on synthetic and/ or naturally occurring iron oxide reds, yellows and blacks. Each of these is blended by manufacturers as part of a highly technical, factory-based process to produce a range of attractive shades, including browns, marigolds and olive green. The pigments physically bind to grains of cementitious material, changing the overall colour of the mixture.
PRECISION
Eliminating significant colour pigment variation is crucial for coloured mortar consistency. This applies to powder and granulated materials. To achieve a uniform colour, cement, pigment and admixture quantities must be precisely measured into the mix. The same accuracy should be applied to water content, as the water:cement ratio will significantly impact the mortar’s final colour.
Cement colour is also key to achieving a consistent mortar appearance. This is particularly relevant to mortars manufactured with low pigment dosage rates, such as light buff shades. In this case, a cement from the same source should be used. A less critical factor in eliminating mortar appearance variables is ensuring consistent aggregate colour. Attention should also be paid to the water content, as it can impact the mortar’s final colour. The specification of factory-produced mortars ensures the accurate application of constituent materials, guaranteeing the finished mortar’s consistent appearance.
SITE-BASED BEST PRACTICE
With the constituent materials’ quality secured, along with batching accuracy, best practice in the mortar’s on-site management and application becomes essential. This responsibility rests with the contractor. Silo delivery and storage is a must for protecting dry mortars from the elements, and other external factors such as moisture, dust and debris.
Finished masonry should be protected from the elements until it is fully cured to preserve its consistency and strength. In terms of application, mortar joints should be tooled in a consistent fashion at the same degree of hardness and moisture content.
Once installed, a well-designed, correctly applied coloured masonry structure should remain maintenance-free throughout its life cycle. The controlled manufacturing conditions of the dry mortar’s production ensure consistency that upholds a building’s durability and aesthetic appeal. www.cpieuromix.com