WORKING WITH INCA GRANITE FACE BRICKS

SIZE: There are two sizes of face brick: Imperial and Metric. The imperial brick (222x90x72mm) courses alongside the conventional brick or MAXI or JUMBO II. The metric brick (220x90x90) is designed to course with the larger concrete block – 2 courses of 90mm equal the 190mm height of the concrete block. Choose the size that fits the design of your building and courses with the inner skin.

COLOUR CONSISTENCY: Slight changes can occur in production due to many factors: climate, temperature and variations in the aggregates or cement. Any colour difference is highlighted if the brickwork starts with another batch on a new lift, forming a horizontal colour band. Bricks should be blended by feeding the bricklayers from two delivery loads. Make sure that the full quantity is ordered so that it can be made in one batch.

MORTAR COLOUR: Mortar joints make up nearly 20% of the surface area of the wall. Variations in mortar colour will impart a different shade to the brickwork. Cement varies in colour depending on the factory source. Sands vary all the time. Make sure that the cement and the sand come from the same source each time a new mortar batch is mixed. See Mortar mix

MORTAR MIX: Avoid strong (rich cement) mixes. The best mortar is the weakest mix consistent with the regulations. Most face brick walls require a Grade II mortar – 1 part cement, 1 part lime, 6 parts sand. The batches should be carefully measured out by volume and mixed with a mechanical mixer. Lime is good in that it: 1. Lightens the mortar colour and makes it more consistent, 2. Slows down the setting so that minute movements can take place without cracking, 3. Makes the mortar easier to use, 4. Resists white weeping that leeches from mortar joints.

POINTING: A well laid face brick wall must have tidy, clean and rain-resistant joints. The GRANITE face brick is very dense and will resist moisture penetration, but the joint will be the weakest link if not treat properly. Joints are almost 20% of the brickwork so it is worth the effort to make them moisture resistant. The mortar should be pressed into the joint to make closed outer surface. Our recommended treatment is to press the joint with half-round steel tool (10mm-12mm diam.) creating a smooth concave surface about 3-5mm deep. The common raked joint is poor because it leaves an open surface and ledges for water and dirt to accumulate.

JOINT THICKNESS should be 10mm.

KEEP THE FACE CLEAN. Mortar smears can be unsightly. Although the siliconed face will resist mortar sticking to it, excess mortar should be brushed off after it has partially set (about 1 hour). Do not use acid to remove wet mortar smears as it may etch the brick face and change the colour. In this situation it is best to chip the offending face away. Protect the face work with plastic sheeting when casting floor slabs or lintels. Sloppy grout, once set, can be extremely difficult to remove from face bricks.