Management Team

In one word, how can we sum up what motivates our management team?


A passion for knowledge.

A passion for excellence.

A passion to produce the most attention-grabbing, discussion-provoking, and highest quality signs in Houston and around the country.

Every member of our leadership team is dedicated to producing unique signage that enhances your organization’s brand and effectively communicates your message.

Our Team

Gregg Hollenberg, President & CEO

Gregg Hollenberg has extensive executive management experience in a variety of industries. Gregg joined National Signs in Houston as Chief Operating Officer in 2008, was named President in 2010 and added the role of CEO in 2012. Prior to joining National Signs, Gregg held P&L responsibilities for several growing organizations including two multi-billion dollar divisions of a Fortune 500 retail electricity provider and manufacturer of specialty concrete products.

Gregg is actively involved in local community and industry organizations, including the President of the Texas Sign Association, Board of Directors of the Greater Houston Sign Association, Board of Directors of Hermann Park Conservancy.  He is a former member of the Board of Directors of the Houston Better Business Bureau. Gregg holds a Bachelor of Arts in Economics and Masters of Business Administration from Duke University.

SenLy Fox, VP Sales and Marketing

SenLy Fox joined National Signs in 2013 with over 15 years of sales leadership experience in the telecommunications industry. She has won numerous national awards at every level for establishing, leading, and growing high-performance sales organizations.

In addition to her professional role, SenLy serves on the Board of Directors of Pink Door, a Houston charity for women cancer survivors and previously served on the Alumni Board of Directors of the University of Houston Bauer College of Business. SenLy earned a Bachelor of Business Administration in Marketing and Psychology from the University of Houston.

John Graff, VP Operations

John Graff has over 40 years of experience in sign manufacturing and installation at several large Houston sign companies. Employed by National Signs since 2000, John has responsibility for all fabrication, scheduling, installation, safety, and quality control. In addition to his many years of hands-on experience, John is UL certified and holds a Journeyman electrician license in Texas.

Cheri Niedelman, Controller

Cheri Niedelman joined National Signs in 2013. Previously, Cheri held senior staff accounting positions with both private and publicly-held manufacturing firms.  Cheri has managed all areas of accounting, including accounts payable, accounts receivable, payroll, project accounting, and financial reporting. Cheri has a Bachelor of Science in Accounting and an MBA from Kaplan University.