Coloured Mortar

Q Anyone know how the pink mortar colour was derived? It was probably a natural feature due to local materials and procurement methods but I am finding it difficult to match existing with new work. I have tried brick dust, ash from coal and wood, soil and blood ! We also have limewash which is a dark crimson colour and believed to be a feature to West Wales only.

A You are probably correct in saying that the original colour may have derived from natural materials, particularly the sand. This the best way of achieving the colour if you can find a sand but it would be a mistake to choose a sand just for its colour – its grading is much more important. Another suggestion is to use a natural pigment – possibly red oxide. This could either be mixed in with the mortar or ‘painted’ on afterwards. But … Technical Advisory Note 1, written for Historic Scotland by The Scottish Lime Centre (available through the Bookstall) contains a comment that there is evidence that using pigment mixed in the mortar may affect the pore structure of the mortar. Also obtaining a consistent colour may be difficult and requires very thorough mixing – but then variation in colour is a feature of natural materials.