If you apply for professional immigration to the United States, are construction workers skilled or unskilled?

The term construction worker is too general, because scaffolder, bricklayer, porter, tower crane driver, forklift driver, etc. Can be collectively referred to as construction workers, depending on what you do in the construction industry, how long you have worked, and how your skills are-

Technical category: skilled workers: applicants must be competent for jobs that require at least two years of training or work experience;

Non-technical category: the applicant can be competent for a job that does not require two years of training or work experience;