Aging Buildings: Roofing Systems
Roofing systems are more complex than meets the eye, and they can develop structural issues if they are not properly updated and maintained as they age. When assessing the structural integrity of a building’s roofing, the main concern is the age of the roof.
Why Failures Happen
Heat and cold
Thermal cycling occurs when materials expand in the heat and contract in the cold. The stress caused by the sudden temperature changes can lead to blistering, tenting, cracking, splitting, and membrane, adhesive and seam failures.
Snow and ice can stress roofing systems due to the weight of the accumulation, causing cracks to form. If water gets into those cracks, it may cause water damage to the internal structure of the building. Ice dams can cause significant gutter damage as well.
Damage from hail includes weakened structural members and accelerated aging.
Sunlight can contribute to the deterioration of membranes, shingles, sealants, and other materials.
Moist and damp conditions from rain, snow, hail and fog can cause material degradation.
Shakes and shingles made from wood can curl, thin or split as they wear out.
Moss, fungus and algae growth
Moss, fungus and algae can cause direct damage to membranes and hold moisture against the roof.
Excessive weight on a roof can cause it to collapse.
Clogged drainage and gutters
Inadequate drainage can cause water to enter the building structure, resulting in wall and ceiling damage.
Poor installation of roofing material can not only be aesthetically unpleasing, but it can also allow water to seep in between cracks and ruin the sheathing underneath.
If a roof fails to protect the building’s structure from water, it can lead to a myriad of issues, such as Mold, Rotting wood, Damage to the electrical system and Foundation problems.
Roofing systems that are not maintained and updated may succumb to stress and pressure, leading to collapse.
What to Look For
Visible damage from the outside
Visible deterioration, missing shingles.
Water spots on the ceiling
A leaking roof can cause discolored, bubbling water spots to form on the ceiling.
Roof blisters are raised areas where there is a loss of adhesion. They occur in all types of roofing systems. If left unmonitored, blistering can lead to saturated insulation and a damaged membrane.
Wind forces can create stress across a roof, causing gravel and ballasted roofs to become displaced. Facilities managers should look for signs of this in the roof’s corners.
Pooled or ponding water can indicate that the structure of the roof is not adequate.
Risk Management Actions
Budgeting for the lifespan of the roof
Roofs can be costly and different roof types can have vastly different life spans.
Ensuring snow is removed
Snow removal can prevent water damage to the roof and the drainage and gutter system.
Conducting regular roof inspections
Commercial-grade roofing should be inspected twice a year, once in the spring and fall.
Performing regular maintenance
Facilities managers should stay on top of routine maintenance, such as cleaning clogged drains, so that minor problems don’t balloon into more significant issues.