MJ Daly has been a premier mechanical contracting firm, headquartered in Waterbury, CT for over 139 years. We specialize in the design, installation, and maintenance of mechanical HVAC, plumbing, and fire protection systems, and we are also an authorized Fike Fire Solutions Dealer, a Johnson Controls and Honeywell Tridium Building Automation Dealer.

We are a proud union company, employing CT and MA licensed mechanics/members of Local 777 for our Plumbing and HVAC Pipe Fitter crews, and Local 669 for our Fire Protection crews. Some of the greatest strengths we can offer to our clients include our ability to fast track, prefabricate, value engineer, and combo package trades into one bid, or a service repair or equipment replacement.  This helps lower your costs.

Please review/share these short video links with your team.  Attached is copy of our presentation placemat for your electronic copy.

Please feel free to also check out our website: https://www.mjdalyllc.com/ and our parent company’s website https://www.ardenbuildingcompanies.com/.

MJ Daly, Service Divisions


Our legacy began in 1882 with horse‐drawn, wooden‐wheeled trailers carrying pipe, mechanical equipment and supplies to each customer’s location. In the summer of 2006, MJ Daly was acquired by Arden Building Companies, LLC of Pawtucket, R.I., the parent company of Rhode Island’s largest mechanical contractor, Arden Engineering Constructors, LLC. Since then, we have re‐committed ourselves to our customers and all their building’s mechanical system’s needs. Our acquisition by Arden Building Companies has enabled us to broaden our ability to provide additional services to our customers such as sheet metal fabrication and installation, design‐build engineering services as well as green energy solutions. We continue to grow as we tirelessly serve customers all over Southern New England helping them design, construct and maintain their building’s mechanical systems in the most efficient, eco‐friendly manner.

For over one hundred thirty eight years, MJ Daly, LLC has ensured that its customers’ fire protection, HVAC and plumbing systems are designed, installed and serviced to meet their needs and save operating costs for the  life of their building. MJ Daly delivers quality installed solutions in mechanical system design, installation and service. As one of New England’s premier fire protection and mechanical contracting firms, MJ Daly is proud to offer a unified approach across the entire lifecycle of a project. From complex heating, ventilating and cooling systems to critical life‐safety systems, to the demands of specialized fabrication needs, the breadth and depth of MJ Daly’s capabilities is unmatched.



MJ Daly designs, installs, repairs, and tests sprinkler systems to protect businesses from the loss a fire can cause. Our complete fire protection systems include wet and dry pipe sprinklers, deluge systems, pre‐action systems, standpipe systems, fire pumps, foam systems as well as above ground water storage tanks and underground fire mains.

We are also an Authorized Dealer for FIKE and Honeywell Fire Alarm/Detection equipment.  As well FIKE Suppression and Extinguisher equipment. Factory trained designers & technicians. Experienced estimating department with PE Registered & NICET IV for large bid spec, Design-Build, and owner-direct projects.


MJ Daly specializes in construction and repair on a full range of heating, cooling and ventilation systems for commercial, industrial, and institutional environments. We offer comprehensive preventative maintenance programs designed to suit any system and fit any budget. Plus, our trained service team is fully equipped and ready to respond to any service call 24/7 to keep customers’ systems operating. M.J. Daly’s proactive approach to service can help customers’ minimize yearly operations and maintenance costs. Our services include installing, repairing, and re‐commissioning specialized controls, chillers, boilers, pumps, air handler units, VRF’s, condensing units, exhaust fans, and roof top units of any manufacturer.

We are also an Authorized Dealer for Johnson Controls and Honeywell Niagara Tridium Based building automation equipment. Factory trained designers & technicians.

HVAC,  Plumbing, and Fire Protection specialized in Design & Installations for high-rise apartments, public schools, private universities, retail facilities, hospitals, medical facilities, and much, much more.

Affiliated with Local 777 (Pipe-Fitters & Plumbers) & Local 669 (Sprinkler Fitters), so labor shortages is never an issue for MJ Daly.
ASME B31.1 Certified Welders, for all power process piping installations (underground and aboveground systems).

Experienced estimating department with PE Registered & EIT Certified Engineers for large bid spec, Design-Build, and owner-direct projects.


MJ Daly’s fabrication division is comprised of a multi‐million dollar, 55,000 square‐foot controlled manufacturing environment offering specialized pipe fabrication and material handling equipment, plus warehousing and logistic support to get the pipe customers need when and where needed. We have been experts in fabrication for over 60 years and our trained production crews are skilled in flawless execution with the use of the latest 3D Project Modeling BIM AutoCad design technologies. We can layout complex mechanical rooms in 3D before fabrication for maximization of space, reduction of waste materials, and faster labor install.

We are also an Authorized Wholesaler/Dealer for Victaulic pipe specialties equipment.  $2+million of in stock items inventoried at our Waterbury warehouse.