Slab-on-Grade Foundations
SLAB-ON-GRADE FOUNDATIONS — GARAGE, ADDITION & OUTBUILDING
Slab-on-grade foundations combine the floor slab and foundation into a single concrete pour. We install monolithic slabs (thickened edge), stem wall slabs, and frost-protected shallow foundations. Every slab-on-grade includes proper subbase preparation, vapor barrier installation, edge insulation in heated applications, reinforcement, and control joint layout. Common applications include garages, workshops, additions, and outbuildings.
Starting at $7 per sq ft
Key Highlights
Monolithic slab
thickened-edge design combining floor and footing in one pour for efficiency.
Frost-protected shallow foundation
insulated slab option for heated buildings in cold climates.
Vapor barrier and insulation
proper moisture and thermal protection for heated applications.
Why Choose Our Slab-on-Grade Foundations
Slab-on-grade foundations are the most economical option for garages, workshops, additions, and outbuildings. We pour monolithic slabs (thickened edge serves as the footing), stem wall slabs, and frost-protected shallow foundations with proper subbase preparation, vapor barrier, insulation where needed, and reinforcement throughout.
Signs You Need Slab-on-Grade Foundations
1. Building a garage or workshop
Detached garages, shops, and outbuildings are ideal candidates for cost-effective slab-on-grade foundations.
Our Process
Step 1 — Site preparation
Excavate, compact subgrade, install granular subbase, and trench thickened edges.
Step 2 — Moisture and insulation
Install vapor barrier and edge insulation (for heated buildings).
Step 3 — Form, reinforce, and pour
Set edge forms, install rebar or mesh, pour concrete, screed, and finish.
Brands & Materials
- Cemstone Ready Mix
- Stego vapor barriers
- Dow rigid insulation
FAQs About Slab-on-Grade Foundations
Do slab-on-grade foundations work in Minnesota?
Yes — for appropriate applications. Unheated structures (detached garages, sheds) use thickened-edge slabs with footings below frost line. Heated structures can use frost-protected shallow foundations (FPSF) with perimeter insulation that allows shallower footing depths.
Pricing
$7 - $15
per sq ft
*Varies by project scope and site conditions.
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When you choose Legacy General Services for your concrete project in the NW Metro, you're choosing a partner committed to quality that lasts.
Reputation
MN-registered contractor since 2023. Insured and trusted by homeowners across the NW Metro.
Transparency
No hidden fees or surprise charges. Upfront pricing on every concrete project—big or small, start to finish.
Efficiency
On-time scheduling and reliable project timelines. We show up when we say we will and finish on schedule.
Quality
Air-entrained, freeze-thaw resistant concrete built for Minnesota winters. Every pour meets or exceeds code.