Colouring Cement based products
Select your question below
How much oxide do I add to achieve different shades of colour?
It is recommended that for a light colour shade 2% of oxide is added for the weight of cement in the mix, 4% for a medium colour and 6% for a dark colour. For example, 63 grams of oxide would be added to a 20kg bag of Mortar to achieve a light colour shade. It is important to note that no more than 10% oxide loading should be added to the cement content as the pigment reaches saturation.
It is recommended that a test panel be prepared before completing the actual job. Allow the test panel to dry for a week to assess the final colour as fresh concrete always dries to a lighter colour after it has been laid.
For convenience, add one small pot of oxide per 20kg bag of Cement Australia Render It™ product.
What are the major factors that cause colour variation in a job that incorporates oxides?
Colour variation can be caused by changes in the amount of water added to the mix, cement type and colour, change in aggregate colour or sizing, curing temperature, incorporation of admixtures, finishing of the concrete surface and inaccurate weighing of raw materials including the oxide. It is recommended that the same source of raw materials is used for the entire project.
When using Cement Australia oxides to colour your own mix, premix the oxide with the sand or aggregates for 15 seconds before adding the cement. After adding the cement thoroughly mix again for at least 20 seconds before adding the water.