Module 2 · Practical exercise
Building Science Investigation
Eight Florida field observations. Identify the driving mechanism, separate observation from inference, choose confirming tools, then write the narrative.
Part 1 — Mechanism and confirming method
1. Pensacola, two-story home. Brown staining on the attic side of the roof sheathing is concentrated on the north slope near the ridge; the stain field is dry to the touch and no roof leak path is visible above it.
Most likely mechanism
Confirming tools or next steps (select all that apply)
2. Navarre single-family home. Indoor relative humidity measures 68% at 74°F with the cooling system running; the thermostat fan is set to ON and the equipment cycles for short periods.
Most likely mechanism
Confirming tools or next steps (select all that apply)
3. Destin condo. Water droplets are present on the metal face of a ceiling supply register and on the first two feet of exposed flexible duct in the plenum chase.
Most likely mechanism
Confirming tools or next steps (select all that apply)
4. Gulf Breeze home. The hall bathroom exhaust fan operates but its duct is disconnected inside the attic; the duct end lies on top of the insulation about four feet from the fan housing.
Most likely mechanism
Confirming tools or next steps (select all that apply)
5. Panama City home. Dust streaking is visible at return plenum joints in the garage, supply airflow feels weak at the far bedrooms, and the front door pulls closed on its own when the air handler runs.
Most likely mechanism
Confirming tools or next steps (select all that apply)
6. 30A beach cottage. From the attic, daylight is not visible at the eaves and blown insulation is packed tight against the roof sheathing above the exterior wall top plates for most of the perimeter.
Most likely mechanism
Confirming tools or next steps (select all that apply)
7. Navarre Beach home over a vented crawlspace. The ground is damp with no vapor retarder present, joists near the perimeter read elevated moisture, and the exterior grade slopes toward the foundation on the rear elevation.
Most likely mechanism
Confirming tools or next steps (select all that apply)
8. Pensacola Beach home. After a wind-driven rain event, staining and elevated moisture appear on the interior side of a windward wall below a window head, with sealant separation visible at the window flange.
Most likely mechanism
Confirming tools or next steps (select all that apply)
Part 2 — Observation or inference
Moisture meter readings at the crawlspace rim joist measured 24% wood moisture content.
The attic staining was caused by a roof leak.
The bathroom exhaust duct was disconnected in the attic.
The air conditioning system is oversized for the home.
Indoor relative humidity measured 68% at 74°F in the main living area.
Mold is growing on the sheathing and will spread through the home.
Part 3 — Draft an objective narrative
Write one narrative covering the moisture and air-movement conditions above. State what was observed, where, and any measurement; describe the implication without diagnosing hidden causes; recommend the correct qualified trade; and disclose anything that could not be inspected or must be confirmed. Minimum 80 words.
0 wordsSign in to submit.Complete every mechanism, at least one tool per observation, all six statements, and 80+ words.
Scoring rubric
Mechanism identification40 pts
Each of the eight observations matched to the most likely heat, air, or moisture mechanism driving it.
Observation versus inference15 pts
Six statements correctly separated into what was observed and what was concluded.
Appropriate diagnostic method20 pts
Confirming tools or next steps selected that can actually verify the suspected mechanism.
Objective narrative quality15 pts
Narrative states conditions, locations, and measurements in neutral language without accusation or speculation.
Recommendation and scope control10 pts
Narrative recommends the correct qualified trade and discloses limitations or the need for confirmation.
Mechanism guide
Bulk water. Liquid water from rain, plumbing, or drainage entering the assembly.
Capillary action. Water wicking through porous materials against gravity.
Air-transported moisture. Humid air carried through a hole or gap by a pressure difference.
Vapor diffusion. Water vapor moving through a material by vapor pressure difference.
Surface condensation. Surface below the dew point of the air contacting it.
Conduction / thermal bridging. Heat flow through a conductive path or a gap in the thermal layer.
Mechanical pressure imbalance. Duct leakage or exhaust equipment driving the house negative or positive.
Latent load / poor dehumidification. Equipment not removing enough moisture for the indoor humidity load.
Disclaimer: HIC Inspector Academy is internal educational training for Hurd Inspection Company, LLC. It does not grant a Florida home inspector license, does not satisfy or replace state-approved pre-licensure education, and does not substitute for InterNACHI membership requirements or examinations. Laws, administrative rules, forms, and standards of practice change. Verify all requirements with the Florida Department of Business and Professional Regulation and with InterNACHI before relying on anything in this course. Nothing here is legal advice.