The most common danger associated with rendering comes from performing work at height without appropriate fall protection. 

Rendering from a scaffold is a common, efficient and safe way to apply render to buildings. Note that ladders are not considered appropriate unless there are no other reasonably practicable ways of minimizing the risk.

It is very important that during the rendering process, renders do not remove scaffold ties that ensure the structural integrity of the temporary work platform. As an employer, you can ensure that work is scheduled to avoid the likelihood of this practice occurring.

Further, cement render and other render products may be a hazardous substance or dangerous good. In these instances, safety data sheets must be available in the workplace to ensure the appropriate storage, use of and first aid information is at hand at all times.

Further information can be found in the working safely from heights module (3.2) and scaffolding module (3.3).