This 9,000-sq-ft luxury home demonstrates how Sunlight Contractors, LLC applies advanced building science to create a 300% stronger, moisture-free, and energy-efficient home designed for Louisiana’s hot-humid climate (Zone 2).
Through precise foundation preparation, under-slab insulation, 15-mil vapor barriers, and closed-cell spray foam insulation throughout the roofline and walls, this project showcases out-of-the-box engineering that few contractors in the Gulf South perform.
If homeowners can afford to build this way, it becomes a lifetime investment—a quieter, healthier, and stronger home that dramatically lowers energy and maintenance costs.
Foundation Preparation: Engineering Stability from the Ground Up
The foundation pad was laser-graded for precision and compacted to ≥95 % Modified Proctor Density, the engineering benchmark that ensures the soil is dense and stable enough to prevent settling, cracking, or structural movement.
This process forms a stable foundation base capable of supporting the home for generations.
A 4-to-6-inch capillary break of clean, angular stone was then added to block ground moisture from rising into the slab—critical protection in Louisiana’s moisture-laden soils.
Under-Slab Insulation: Thermal Protection Below Grade
Sunlight Contractors installed 2 inches of high-density ISO board insulation (25 psi compressive strength) under the slab. Panels were tight-jointed, staggered, and shielded from water exposure prior to the pour.
This under-slab insulation creates a thermal barrier that stabilizes slab temperatures, keeps floors warm in winter, and prevents energy loss through the ground.
Vapor Barrier Installation: ASTM E1745 Class A Protection
Above the insulation, the team installed a 15-mil Class A vapor barrier such as Stego Wrap or Perminator, overlapping seams 6–12 inches and sealing to grade beams.
This airtight, radon-resistant membrane blocks ground vapor and humidity, protecting indoor air quality and preventing mold. Every penetration was sealed and patched for long-term durability.
Reinforcement & Concrete Pour: Structural Strength Assurance
Rebar and mesh reinforcement were placed on chairs, never directly on the vapor barrier, preserving membrane integrity and ensuring optimal slab strength.
Before pouring, Sunlight’s team inspected and patched the barrier to maintain continuity, ensuring thermal and vapor alignment at all slab joints and edges.
Closed-Cell Spray Foam: The Ultimate Building Envelope
Sunlight Contractors applied 3 inches of closed-cell spray polyurethane foam (SPF) across the entire roofline and exterior walls, fully encapsulating penetrations and bridging voids.
Closed-cell SPF creates a continuous air, vapor, and thermal barrier that bonds to framing and sheathing, eliminating leaks and reinforcing the building structure.
Few contractors combine insulation, vapor control, and structural reinforcement into one system—this is innovative, out-of-the-box building science in action.
Structural Reinforcement: Up to 300 % Stronger Walls
Independent research by the National Association of Home Builders (NAHB), shows that closed-cell SPF increases wall racking strength by up to 300 %, greatly improving resistance to high winds and seismic forces.
This creates a unified structural system—foundation, walls, and roofline working together for unmatched rigidity and resilience.
Energy Efficiency & Comfort Performance
Winter Benefits
- Warm floors throughout 9,000 sq ft—no drafts or cold zones.
- Floors maintain 3–4 °F of room temperature.
- 25–30 % reduction in heating demand; smaller HVAC systems required.
Summer & Humidity Control
- Under-slab insulation + vapor barrier + spray foam envelope block moisture migration.
- Reduced latent load = less dehumidification and lower utility bills.
- Floors remain dry and stable, protecting hardwood and tile finishes.
Annual Savings
- $4,000–$6,000 per year energy savings (~$40,000–$60,000 over 10 years).
- Longer HVAC lifespan, quieter performance, and cleaner indoor air.
The Irreversibility Factor: Do It Right the First Time
After concrete is poured, under-slab insulation and vapor barriers cannot be retrofitted without demolition.
Skipping these steps locks in decades of thermal loss and moisture intrusion.
By investing now, homeowners gain a structurally reinforced, climate-controlled, and energy-efficient home that remains resilient for generations.
If you can afford it, this advanced system will benefit your home immensely—enhancing value, comfort, and performance for life.
Measured Results
- Up to 300 % increase in wall strength
- 25 % HVAC downsizing verified by load studies
- > 50 % reduction in air infiltration (ACH50)
- Zero ground moisture transmission
- Stable indoor humidity & temperature year-round
Conclusion
Sunlight Contractors’ Gold-Star Building Science Approach integrates structural reinforcement, air-sealing, insulation, and vapor control into one seamless system.
This case study proves that scientific precision + innovation = long-term value.
While others build to code, Sunlight Contractors builds for performance, longevity, and total comfort.
Certifications & Credentials
- SPFA Master Spray Foam Installer
- BPI Gold Star Contractor
- ABAA Certified Air Barrier Experts
- RESNET Certified Energy Rater
- GAF Master Elite Roofer
- Licensed Residential, Commercial, HVAC, Plumbing & Mold Remediation Contractors
- Licensed & Certified in 14 States – Louisiana State Licensing Board for Contractors (LSLBC)