Sunlight Contractors, LLC — Gold-Star Building-Science Division
The Hobson residence, a 120-year-old multi-story home, arrived at Sunlight Contractors
in a state of escalating failure. Mold odors, soft walls, sweating ducts, attic
contamination, uncomfortable humidity, and recurring water leaks had plagued the
home for years. What began as a simple concern about “high humidity” evolved into a
comprehensive forensic investigation that revealed deep structural failures, severe
moisture imbalance, stachybotrys mold, and a building envelope compromised across
multiple planes.
This case study documents the complete building-science remediation performed by
Sunlight Contractors from the first diagnostic reading to the final structural stabilization.
It demonstrates how Louisiana’s most credentialed building-science contractor restored
a failing home using scientific methodology, multi-licensed expertise, and certified
environmental remediation standards.
FOUNDATION OF THE PROBLEM: A HOUSE IN FAILURE MODE
When Sunlight Contractors first evaluated the Hobson home, every critical pressure
boundary of the building showed signs of moisture-driven deterioration. Subfloor joists
and beams were registering moisture levels between 25 and 28 percent, with isolated
measurements reaching as high as 38 percent. These readings far exceeded the safe
wood-stability threshold of 10–12 percent and confirmed that fungal growth conditions
had been active for a long time.
The attic, which acts as the upper boundary of the stack effect, was heavily
contaminated. Laboratory testing from EMSL revealed Stachybotrys, Chaetomium,
Cladosporium, and extremely high Aspergillus/Penicillium counts in attic framing and
insulation. The crawlspace — the lower boundary of the same pressure system —
showed Condition 3 fungal growth, meaning the air in the home was circulating through
mold-contaminated cavities both above and below the living space.
Sunlight quickly determined that this was not a simple leak or isolated humidity problem.
It was a full-home failure mode driven by long-term moisture intrusion from the
refrigerator and ice maker lines, hidden air pathways, unbalanced HVAC pressures, wet
and sweating duct work, compromised roofing systems, and balloon-frame airflow
connecting every contaminated space together.
DISCOVERY THROUGH DIAGNOSTICS
A comprehensive forensic inspection revealed the true extent of the damage. Thermal
imaging showed cold, wet pockets behind first and second-story walls, indicating hidden
water absorption from exterior envelope breaches. Wind-driven rain was migrating
through chimney flashing failures, deteriorated siding, rotted plywood, and improperly
sloped TPO roofing systems that allowed water to pond above critical structural areas.
Inside the crawlspace, sweating ductwork was dripping condensate onto floor joists.
The HVAC system was unintentionally drawing humid crawlspace air into the home
while simultaneously pushing conditioned air back into the crawlspace — creating a
continuous moisture loop that kept the structure wet year-round.
Wall cavities were saturated, attic cavities were contaminated, and the ducts that were
supposed to deliver clean, conditioned air were themselves a source of re-
contamination.
These findings collectively proved that the home had developed a multi-directional
moisture and mold cycle that could not be corrected piecemeal. A complete, scientific
building-science remediation was required.
SUBFLOOR &; CRAWLSPACE RESTORATION — BREAKING THE MOISTURE CYCLE
The restoration began beneath the home. Before any insulation or reconstruction could
occur, the structural wood had to be returned to a safe moisture content. Sunlight
Contractors removed over 3,300 square feet of debris beneath the home, disinfected
the entire crawlspace multiple times with EPA-certified Mold Stat, Shockwave, and
scrubbed all wood surfaces with JO-MAX and RMR solutions.
Because the moisture levels were dangerously high, the crawlspace was engineered
into a controlled thermal-drying chamber. Heavy plastic was hung along the perimeter,
two indirect 500,000-BTU heaters were placed inside the crawlspace, and negative-
pressure exhaust systems were installed to evacuate moisture as the wood released it.
Daily moisture readings were taken until the structure reached equilibrium moisture
content below ten percent.
Once dry, Sunlight applied Bora-Care with tracer dye to every structural member,
permanently protecting the wood from future mold and termite activity. Only after the
moisture content stabilized was the entire subfloor encapsulated with four to four and a
half inches of 2LB closed-cell spray foam creating a monolithic Class-I vapor barrier
that sealed the structure, increased racking strength, and permanently prevented vapor
migration upward.
ATTIC RESTORATION — CLEANING THE TOP OF THE STACK
Above the home, the attic presented another major challenge. More than a century of
dust, cellulose, rodent debris, and contaminated insulation had collected there. The
attic’s porous surfaces were saturated with mold spores, and the insulation itself was
colonized with fungal growth.
Sunlight Contractors extracted every inch of insulation using a 300-foot vacuum hose,
disinfected the rafters, decking, and framing with Mold Stat, Shockwave, JO-MAX, and
RMR, and performed multi-cycle HEPA vacuuming and negative-pressure containment.
The HVAC ductwork throughout the house was replaced including the plenum, and the
refrigerant lines were sanitized to stop re-aerosolization of mold into the living space.
Once remediated, the attic roof deck, walls, and cathedral ceiling were encapsulated
with three and a half to four inches of 2LB closed-cell spray foam, converting the attic
into a sealed, conditioned, and climate-controlled envelope.
This restored balance to the building’s upper pressure boundary and eliminated the
uncontrolled air leakage that had been pulling contaminated attic air into the home.
WALL CAVITY & INTERIOR STRUCTURAL REPAIR
The kitchen was one of the epicenters of contamination. Behind the cabinets, moisture
had seeped into structural studs, sheathing, and drywall — creating mold blooms
hidden from view. Sunlight Contractors performed a controlled demolition, removed all
cabinetry, opened wall cavities, disinfected the framing, dried the structure, replaced
compromised studs, and rebuilt the walls using moisture- and mold-resistant drywall.
The pantry required similar work, as water had traveled through wall chases and
created fungal growth across wallboards and trim. After full disinfection, the entire
pantry structure — including shelving and trim — was rebuilt.
Upstairs, wind-driven rain had soaked the girls’ and boys’ bedroom walls. Sheetrock
was cut out two feet upward around room perimeters, wet insulation was removed,
cavities were disinfected, moisture was stabilized, and the walls were rebuilt from the
studs outward using mold-inhibiting products.
ROOFING, FLASHING & SIDING CORRECTIONS — STOPPING THE WATER
ENTRY
The structural failures traced back to the home’s exterior envelope. Four separate
chimney flashing assemblies were leaking, and the chimney caps were failing. Sunlight
replaced all flashing and installed new custom 26-gauge metal caps.
Two sloped TPO roof systems were found to be improperly pitched and were holding
water. Both roofs were completely rebuilt, including new plywood, polyurethane slope
boards, rubberized storm guard underlayment, slip sheets, and new TPO membrane
systems. Additional roofing materials were replaced after discovering rot beneath
shingles and TPO transitions.
A large section of the main TPO roof was also replaced due to moisture entrapment and
plywood rot, confirming years of undetected roof leakage.
Along the exterior walls, damaged siding, rotted plywood, and failed Tyvek were
replaced. This restored a proper drainage plane and stopped water from migrating into
second-story walls.
DUCTWORK, HVAC & INDOOR AIR PURIFICATION
Under the home, the ductwork was saturated from condensation caused by high
humidity and cold supply air which had to be replaced. The ducts and plenum were
flash-sprayed with closed-cell foam to prevent future sweating and to stabilize supply
temperatures. This also sealed the ducts from crawlspace air infiltration creating R-14
on the duct work.
To eliminate airborne contamination, Sunlight Contractors installed three REME Halo air
purification units in the home’s HVAC systems and two additional units in the
dehumidifiers. This corrected airborne mold distribution and significantly improved
indoor air quality.
WHOLE-HOME REMEDIATION & FINAL DECONTAMINATION
Once structural repairs, encapsulation, insulation and roof restoration were completed,
the entire home underwent whole-home decontamination again. This included HEPA
vacuuming of every surface, spray-and-wipe disinfection of all walls, fogging of the
interior structure, and continuous negative air pressure to remove spores from the air.
Because the home had reached a Condition 3 contamination, the homeowners were
instructed to not only leave the home during the project but to deep-clean all clothing,
bedding, personal belongings, shoes, toys, and dog items to ensure no spores could re-
enter the environment after PRV clearance.
FINAL RESULTS — A STABILIZED, PROTECTED AND HEALTHY HOME
After 2 months of scientific remediation, reconstruction, and building-envelope
correction, the Hobson residence achieved full structural and environmental stability.
The crawlspace and attic, which once the greatest sources of mold and moisture —
became sealed, conditioned, vapor-controlled spaces. The ductwork stopped sweating,
the HVAC system delivered clean air, and the building envelope stopped absorbing
stormwater. Roof leaks were eliminated, structural moisture returned to safe levels, and
the entire home achieved balanced temperature, humidity, and pressure control.
Today, the Hobson home is safer, stronger, healthier, and more energy-efficient than it
ever was in its 120-year history.
CONCLUSION
The Hobson project exemplifies Sunlight Contractors’ unmatched ability to diagnose
and restore complex building-science failures. With multi-state licensing, environmental
credentials, SPFA Master Installer certification, ABAA air-barrier expertise, BPI Gold-
Star building-performance accreditation, and full roofing, structural, HVAC, electrical,
and mold-remediation licensing, Sunlight Contractors delivered a complete turnkey
restoration.
No other contractor in Louisiana possesses the licensing, science background, or field
expertise required to execute a remediation of this magnitude.