The Sternbergs have lived in their Chattanooga home for many years. They knew they might be facing a roof replacement, but were hoping to wait a few years. Earlier, because of a roof leak, we were making some repairs to the ceiling in their home, and we noted a good bit of black mildew covering the attic insulation and the back of the ceiling drywall. Later, while repairing a hole in the roof where a branch had fallen, we noted that the roof was in very poor condition. The roof shingles looked like they had been baked. They lost most of their granules and the edges were curved and brittle; all signs of a poorly ventilated roof. Today, shingle manufacturers will honor their material warranties only if the roof is properly vented, because without proper ventilation, the heat from the attic will literally cook the shingles and drastically reduce their useful life. We continued our inspection, and up top, this roof had what appeared to be plenty of ventilation: several large passive roof vents were installed near the peak. But at the eaves we quickly noted that the house did not have any overhang at all. No overhang meant no soffit, no soffit meant no soffit vents. Normally hot air in the attic will rise and exit out of vents located on the roof or at the gable vents at the end of the house. This air flow would create a convection current that would pull cool air into the attic space from under the eave through a series of grilled openings called soffit vents. The cool air would replace the hot air, keeping the attic cool, and therefore, keep the roofing cool. Without soffit vents,there was no makeup air, and this in turn, caused the air in the attic to stagnate and get very hot, and caused the shingles to age prematurely. Without proper ventilation, it also meant that water vapor exiting the house would remain in the attic until the air cooled causing the moisture to condense and wet the attic insulation. This reduced the insulation value and promoted mold and mildew growth. This explained the black mildew in the ceiling. So to correct the problem soffit vents should be installed. But how do you ventilate the soffits when there aren’t any?
After researching, I turned up the perfect solution to the problem: The In-Vent by Cor-A-Vent. The In Vent is a continuous, On-The-Roof-Intake vent that can be installed when soffit vents are not possible. Simple to install, the In Vent is a low-profile rigid vent that is installed over an opening cut into the top of the roof just above the roof edge. Covered with shingles, it is nearly invisible, and with 10″ per inch Net Free Vent Area provides the same performance as a comparable continuous soffit vent. We installed new shingles, replaced the roof vents with a continuous ridge vent, and installed the In Vent on all sides of the lower part of the roof. We could feel the air current coming from the ridge vent as we installed it. This installation will ensure a cool, long lasting roof, and will be one less thing they will have to worry about.
Comments on this entry are closed.