S3h is a proud union contractor, maintaining a strong working relationship with various local union business managers, business agents and craftspeople. The Union’s ability to provide highly skilled and well-trained professionals on a consistent basis has proven to be an asset in all new and existing markets.

Current Union affiliations include:


Local 105 – Sheet Metal Workers
Local 104 – Sheet Metal Workers
District Council 16 – Pipefitters/Plumbers/Refrigeration
Local 393 – Plumbers and Pipefitters
Local 38 – Plumbers and Pipefitters


Local 88 – Sheet Metal Workers
Local 525 – Plumbers and Pipefitters

Washington, D.C.

Local 5 – Plumbers
Local 602 – Steamfitters


Local 486 – Plumbers and Pipefitters

Mid-Atlantic (VA, MD, D.C.)

Local 100 – Sheet Metal