Trusted Construction
Our Services
Dependable Services Backed by Experience
Still proudly family-run and based in Middlesex, NJ, MarNic specializes in roll-off dumpsters, concrete, demolition, fencing, and more. Whether it’s a one-day dumpster rental or a multi-phase construction project, every job gets the same attention to detail and commitment to quality.
Commercial Fencing, Gates & Guardrails
- Commercial fence installation
- Galvanized gate manufacturing, repairs, and replacements
- Gate operator maintenance and repair
- Metal and wood guardrail installation and repairs
Excavation, Concrete & Demolition
- Skid steer and excavator services
- Re-grading, trenching, drainage, and more
- Saw cutting and core drilling
- Concrete slab, step, and sidewalk replacements or installs
- Full building and interior demolition—dumpsters included
Roll-Off Dumpster Services
- 10–30 yard dumpsters available
- Dump trailers for restricted or tight-access sites
- Clean-outs, construction debris, roofing, concrete, tree and brush removal
About Us
Trusted Commercial Construction in New Jersey
Mar-Nic General Contractors is a commercial construction company serving New Jersey and beyond.
Established in 1993, we’re a family-run company with over 50 years of combined hands-on experience. We focus on the work—concrete, fencing, demolition, dumpsters, and more—and take pride in being reliable, responsive, and easy to work with.
Our Story
Built on Family. Driven by Integrity.
Mar-Nic General Contractors was founded in 1993 by husband-and-wife team John and Donna Sedlazek with a simple belief: do the work the right way, treat people honestly, and never cut corners. Named after their sons, Mark and Nicholas, Mar-Nic was built on grit, hands-on experience, and a reputation for being dependable and responsive. What began with small local projects quickly grew into a trusted partner for commercial and industrial clients across Central New Jersey.
In 2025, Mar-Nic entered its next chapter under the leadership of Eric and Amanda Tibok, longtime friends of the Sedlazeks who share the same commitment to quality and integrity. Eric brings over 20 years of field experience across residential, commercial, and utility projects, while Amanda supports the business behind the scenes.
Now raising their own young family, the Tiboks are deeply invested in Mar-Nic’s future and the communities they serve. For them, this isn’t just a business—it’s a legacy built on hard work, trust, and good people.
Where We Work
Proudly Serving Clients Across Central & North Jersey
We’re based in Middlesex, NJ and proudly serve commercial and residential clients across Central Jersey and beyond. Our service area depends on the project, and we’re always happy to travel. Not sure if we cover your area? Call or text us. Chances are, we do.
- Middlesex County
- Somerset County
- Union County
- Essex County
Our Testimonials
See What Our Clients Are Saying
Questions? Estimates? We're Just a Call Away.
Contact us to discuss your project. No pressure, just honest advice.
Contact Us
At Mar-Nic, we don’t just do the work. We show up, we follow through, and we treat your project like it’s our own. From one-day dumpster rentals to complex multi-phase construction projects, you can count on us to deliver dependable service every step of the way. Our team shows up prepared, gets the job done efficiently, and makes sure no detail is overlooked.
(732) 828-9109 [email protected]502 Jersey Ave, New Brunswick, NJ 08901