Addition Foundation Contractor · Chicagoland
Concrete Foundations
for Additions.
Planning an addition starts below grade. CLMC builds footings, foundation walls, slabs, and concrete bases for residential and commercial additions across Chicagoland.
Veteran-owned · Footings · Foundations · Slabs · Chicagoland
Our Scope
The Foundation Has to Be Right First.
CLMC focuses on the concrete, foundation, grading, and masonry portions of addition projects. We can work alongside your general contractor, architect, or builder to complete the structural base correctly.
We don't handle framing, roofing, plumbing, electrical, HVAC, or interior finishing. Our scope is the base — the footings, walls, slabs, drainage, and masonry that determines whether an addition holds up or fails.
Project Examples
Foundation Work for Additions
Real addition foundation work — footings, walls, slabs, and excavation tied into existing homes.
Concrete foundation for residential addition
Foundation walls tied into existing home
Foundation walls and slab prep
Excavation and concrete foundation work
Residential addition foundation package
Scope of Work
What We Handle
The Risk
Why Addition Foundations Fail
Undersized Footings
Footings not engineered for the load of the addition cause settlement and cracking that worsens every season.
Poor Soil Prep
Uncompacted or improperly prepared soil under footings and slabs leads to differential settlement between old and new construction.
Bad Grading
Grade that slopes toward the foundation instead of away from it guarantees water problems from day one.
Weak Drainage
Missing or undersized drainage systems allow hydrostatic pressure to build against new foundation walls.
Improper Frost-Depth Planning
Footings poured above frost depth heave during freeze-thaw cycles, cracking walls and slabs within the first winter.
Poor Reinforcement
Missing or incorrectly placed rebar and reinforcement leads to cracking under load and thermal stress.
Bad Concrete Placement
Concrete poured too wet, poorly consolidated, or finished incorrectly develops surface defects and structural weakness.
Weak Tie-Ins
New foundation work not properly connected to the existing structure creates a seam that separates over time.
Water Intrusion
Waterproofing applied incorrectly or skipped below grade allows water to saturate foundation walls and enter the structure.
Residential
Residential Addition Foundations
Home additions need foundations engineered to connect seamlessly with the existing structure. We handle the concrete and foundation scope for room additions, garage additions, and rear additions. We do not handle interior remodeling, framing, or finishing.
Commercial
Commercial Addition Foundations
Commercial expansions require foundation and slab packages engineered for heavier loads, commercial traffic, and long-term durability. We handle the structural concrete and foundation scope — not full commercial GC work.
How We Work
Our Process
01
Review Plans and Site Conditions
We review your architectural plans, assess soil conditions, access points, and the existing structure to understand the full foundation scope before pricing.
02
Confirm Access, Grade, and Excavation
We confirm site access, existing grades, excavation depths, and sequencing with your GC, architect, or builder so foundation work fits the project schedule.
03
Layout and Footing Preparation
Footings are laid out, excavated below frost depth, and prepped with proper reinforcement and soil compaction before any concrete is ordered.
04
Foundation Wall or Slab Forming
Foundation walls and slabs are formed to spec with correct reinforcement, control joints, and elevation. Forms are checked for plumb, level, and alignment.
05
Concrete Placement and Finishing
Concrete is placed, consolidated, and finished to the correct spec. Slabs are floated, troweled, and cured properly. Control joints are cut at the right intervals.
06
Drainage and Waterproofing Coordination
Foundation waterproofing, drainage board, and below-grade water management are installed before backfill. Every penetration and transition is sealed.
07
Cleanup and Final Review
Site is cleaned. Form ties are stripped. We walk the project with you to confirm every scope item is done right before the build moves forward.
Questions
FAQ: Addition Foundations
Do you build full additions or just the foundation?
We handle the foundation and concrete scope only: footings, foundation walls, slabs, grading coordination, drainage, and waterproofing. Framing, roofing, interior finishes, plumbing, electrical, and HVAC are handled by your general contractor or builder. We work alongside your project team to make sure the base is right first.
Can you pour a concrete foundation for a home addition?
Yes. We pour footings, foundation walls, and slabs for home additions. Whether it's a rear addition, room addition, or garage addition, we handle the concrete and foundation scope engineered for Chicago-area soil and freeze-thaw conditions.
Do addition footings need to be below frost depth?
Yes. Illinois frost depth is 42 inches. Footings for any permanent structure must extend below that depth to prevent frost heave. The exact footing size and reinforcement depends on the load of the addition, soil conditions, and engineering requirements. We spec footings based on the project, not what's cheapest to pour.
Can you handle garage addition foundations?
Yes. We handle garage slabs, footings, and foundation walls for both attached and detached garage additions. We also handle driveway and flatwork tie-ins where needed.
Do you work with general contractors or architects?
Yes. We routinely coordinate with general contractors, architects, and builders. We review plans, confirm scope and sequencing, and handle the concrete and foundation work that falls within our expertise. Clear communication with your project team is part of every addition foundation we pour.
Can you help with grading and drainage around the foundation?
Yes. Proper grading, drainage paths, and waterproofing are part of the foundation package. If grading slopes toward the foundation or drainage is undersized, water problems start on day one. We make sure the base, the drainage, and the waterproofing are right before backfill.
Do you handle commercial addition foundations?
Yes. We handle foundation packages for commercial additions including retail expansions, building extensions, and service bay additions. Commercial projects are scoped based on structural requirements, load ratings, access, and scheduling needs.
What areas do you serve?
CLMC serves Chicagoland, including many western suburbs and Fox Valley communities — Naperville, Aurora, Batavia, Geneva, St. Charles, Wheaton, Oak Brook, Downers Grove, Elmhurst, Hinsdale, and nearby suburbs.
Where We Work
Areas We Serve
We handle addition foundation work throughout the western and southwestern suburbs, including Naperville, Aurora, Batavia, Geneva, St. Charles, Wheaton, Oak Brook, Downers Grove, Elmhurst, Hinsdale, La Grange, and Clarendon Hills.
Our crews also work in Glen Ellyn, Lombard, Western Springs, Burr Ridge, River Forest, Oak Park, and across DuPage, Will, Kane, and Cook counties. Same standard on every project.