Seeing the Building: Outside Many important clues to building performance are visible from the curb. The age, style, and geometry of the building will indicate where many systematic defects can be found. Problem buildings often cause premature damage to the exterior finish systems. Often the owners will attempt to mitigate problems by retrofitting equipment on the exterior. These clues can lead us to toward a solution before we meet the occupants or see the problem. If the roof deck is deformed, it may be seriously damaged from condensation or leakage. If roof ice has caused trouble in the past, additional vents and even heating cable can be seen. New chimneys may mean that auxiliary heaters were needed to deal with discomfort or high fuel bills. Deteriorated trim and siding or paint failures at the eaves and gables point to high moisture content in the attic. Shingle and flashing damage, especially hatchet marks, indicate destructive ice damming. If paint failure is confined to certain areas, we can tell that the construction is different or the pressures are different. Blistered paint all over the building indicates a mechanical pressurization of the conditioned space. Button vents drilled into the siding has been used to combat wet walls. Chimney top flashing and other contraptions can be a sign of back drafting and cellar depressurization. A board held down over the top of a flue is a clear sign of back drafting. During cold months, light snow and frost will melt rapidly off the roof in areas of high heat flux. This often creates vertical melt patterns over the vented areas of sloped ceilings. In warmer weather, these same patterns can be detected by the evaporation of early morning due. Huge ridges of ice and icicles that stretch down to the ground make the case for heat loss to the roof more obvious. In large buildings with additions, icicles that break off of the upper roofs will harpoon lower ones. You can see this fixed by buckets of tar poured into the resulting holes, and wooden barricades such as shipping pallets installed to absorb the impact of the ice fall. Back | Next