One of the things you need to consider before settling on a silo cleaning contractor is the cost you are likely to incur. Consider the various service providers in the region and settle on the one that seems most affordable. Otherwise, you may end up hiring a provider that is too expensive for you to pay easily.
Another factor to consider is the reputation of the service provider. Pick a contractor that commands respect from various sections of the society. This will help guard you against unfortunate incidents such as loss of property or damage to facilities.
The next thing to look into is the amount of time the particular contractor has been in service. Those with considerable experience are likely to have sound techniques and state of the art equipment to handle any type of cleaning project. It is also important to choose a contractor that has clear communication options.