Photos of HEC projects
OBSERVATIONS AND INSPECTIONS
Exterior ventilation (soffit & roof), Interior (thermal bypasses, mechanical vents, & humidifiers), Attic (thermal bypasses, mechanical and passive ventilation, & insulation)
My initial exterior observation of the home was a standard stick built ranch home. It has a 24 inches overhang with 16 inches x 8 inches soffit vents cut in the plywood for intake ventilation. It uses both ridge and passive mushroom vents for exhaust. There is also a power ventilator.
The interior of the home showed several areas of thermal bypass. There were a multitude of soffits, can lights, and a flue chase. There was an all house fan in the common hall way. There were two bathroom vent fans and an over the range microwave with an exhaust vent. There is a laundry room with a dryer vented through the exterior wall. There were a few areas of condensation stains on the drywall ceilings near the exterior wall. The furnace in the basement did have an all house humidifier and was set at 6 out of 7. Part of the house was over a crawlspace. The crawlspace was gravel over a vapor barrier. Digging into the gravel showed no signs of moisture above the vapor barrier.
The attic inspection showed the home was insulated with 10-12 inches of blown fiberglass. There was fiberglass batts stuffed into the eave line. Some of the stuffing was moved in some areas. The roof deck had spot mold on the rafters and decking on the south and west side. The roof deck and the rafters on the north end of the house were completely covered with mold. The east elevation had some spot areas as of mold as well. The worst cases were above the kitchen and the bathrooms. The bathroom vent fans were dumping directly into the insulation. The kitchen range vent terminated into the exterior soffit overhang. The all house fan had a very poorly constructed lid. The penetrations in the top plates were not sealed for fire stop. The access panel cover was not insulated.
High moisture content, improper exhaust ventilation, and thermal bypasses.
The moisture content was set to high on the humidifier. Leading to a high moisture content in the home. The improper venting of the over the range microwave vent let warm moist air from cooking move into the exterior eave. The eave then allowed the air to flow into the attic. The improper bathroom exhaust vent terminated directly into the attic insulation. The many thermal bypasses allowed excessive amounts of warm moist air to escape into the attic. The powered roof ventilator compounded the problem by drawing conditioned air from the house into the attic. The attic ventilation could not keep up and allowed the warm moisture laden air to sit on the roof rafters and roof sheathing. This constant wetting provided and supported a viable place for mold spores to become active and grow.
Remove, Remediate, and Replace
The attic insulation in its entirety was removed from eave to eave. First the loose blown fiberglass was removed by vacuum to drop containers. Then the remaining fiberglass batts and old baffles were wrapped and disposed of as well.
The attic roof deck and rafters were then physically scrubbed and sprayed with to remediate the mold and fungal growth. Then the roof and rafters were sprayed with Mycodyne product to seal the areas from returning growth.
Then the proper ventilation was installed to remove the range vent from the soffit and go through the roof and take the two bathroom vents through the roof. The thermal bypasses were capped with rigid sheathing and the joints were air sealed. The eave line was stuffed properly, exposing the top plate, and vent chutes (baffles) were added throughout the attic. The penetrations and junction boxes were air sealed. The all house fan was covered with an insulated box with a functioning lid. The access panel cover was insulated with foam sheathing. The attic was then insulated with R-38, code minimum, blown cellulose.