What is the biggest mistake in an interview?

The biggest mistake you can make on an construction interview is to ask how much the job pays, or to bring up pay before the construction employer brings it up. Always let the construction employer bring up the subject of pay. If you bring it up you will usually be perceived as someone who focused on the money side of job satisfaction and a likely opportunist who will move jobs to the highest bidder. You will also reduce your negotiating strength by being the first one mentioning money. Let the construction employer discuss the pay range before you mention your expectations. If you have to give up your expectations first, make sure to indicate what you have been earning and then tell them you would be looking to make a construction career move that offers a greater challenge and a greater pay potential.