Render falling off of stonework

Stone is one of the major building materials used in South East Wales. It was used on conjunction with bricks and lime mortar to create the solid external walls that are so common in the towns and cities of the area. Much of this stone is granite, which came across from places like Ireland as ballast in the coal ships. Modern cement does not adhere (stick) to stone at all well, even using additional adhesives like PVA it can be difficult to get a good binding between the two. Cement render, therefore is quite likely to come way from large areas of stonework because it is not joined to it properly.

Remedy

Use a lime render. Lime and stone work well together and will provide a finish that will last much longer and that will allow the wall to be recycled easily if required, as lime can be removed from stone and brick, thus allowing them to be reused rather than crushed for hardcore or sent to landfill. For more information visit www.lime.org.uk.