How to get a good reference from a bad construction employer?

The best references are from individuals who have agreed to provide you a written reference. If they won't provide such you should be suspect of their reference. Those that will provide you a written reference rarely change their story over time. It is always important to speak to your references before submitting them to a new construction employer to make sure they are supportive. Don't assume things are fine because you can never tell what may have happened over time since your last communication with the reference.