Book of Giants

CONTRACTOR's Top 100 mechanical contractors and who they are


Photo 201218181 © Pramote Polyamate |
A Haberberger technician welds a section of cast iron pipe at the company's new piping facility.

Tale of Two Giants

April 28, 2023
Southland Industries
The new Central Records Complex (CRC) located in Winchester, Virginia.
Harris Co.
A large prefabricated piping assembly for the Minneapolis Bus Garage job. Note the worker in back for scale.
Photo 79465229 © Prasit Rodphan |
Dreamstime S 79465229
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John W. Danforth Co.
Buffalo Welding Shop

In the Footsteps of Giants

May 7, 2021
Our Giants have responded, adapted, and in many cases found new pathways to success.
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Book of Giants 2021

May 3, 2021
As the nation emerges from the pandemic our Giants have embraced new technology and invested in their people while continuing to deliver essential services for their clients.
Four of TDI's employee-partners. Phot: TDIndustries
Wic Week Updated

TDIndustries Celebrates Women in Construction Week

March 10, 2021
The company is highlighting women in the industry throughout March.
From left to right, Jones, Lackey and Haberberger. Photo: Haberberger, Inc.
Kyle Jones Rick Lakey Sam Haberberger

Haberberger Welcomes Three New Employees

March 8, 2021
The mechanical contractor welcomes Rich Lackey, Sam Haberberger and Kyle Jones.
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Harris Named 2021 Top Workplaces USA

Feb. 1, 2021
Honor highlights people-centered culture and reflects employee initiatives.
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Wiegmann Associates Celebrates its 25th Anniversary

Dec. 28, 2020
The company has now engineered and installed more than $1 billion in commercial HVAC comfort solutions across 42 states.
msan10 / iStock / Getty Images Plus

Staying Successful Means Taking Risks

May 31, 2019
Not one of the 100 companies on our Book of Giants list got there by resting on their laurels.

Sale of Dunbar Mech. to Limbach Falls Through

May 30, 2019
Limbach’s September press release announced their plans to acquire Dunbar Mechanical; the sale agreement was not executed.
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UMC Receives AGC Washington Grand Award for Safety Excellence

May 23, 2019
The award comes on the heels of UMC winning the National 1st Place MCAA/CNA Safety Excellence Award in their category for the second year in a row.