Bonding Adhesives

Some backgrounds have poor sticking properties. Plasterers must be able to work out what kind of background they are working with so they can decide the best treatment use to create a key to apply to the render to the background.
A common method is using a spatter-dash coat which is a mixture of wet sand and cement spattered onto the background to create a key.

There are different types of spatter-dash coat that can be bought such as cementious polymer-modified materials. cementious polymer-modified materials are made with a bonding agent and are usually in a powder form. The powder is mixed with water to create the spatter dash and is then brushed onto the background.
Another type is heavy-duty slurry which is already mixed and is applied using either a roller or a trowel. The background must already be sealed in order to use the heavy-duty slurry to create a key.

Bonding adhesives are used to create a better key for render to stick to. The adhesives come in both powder and liquid form and some need mixing while others are pre-mixed.