WILL YOUR ROOF GO THE DISTANCE?

Roofs, on average, last half of their designed lifetime. Most roofs have a designed lifetime of 20  years, while most buildings are designed to last 50 years. These statements mean the average roof will  last less than a quarter the life span of the building. Here are four major reasons why a commercial roof fails to go the distance. 

Mother Nature 

When you think of reasons why your roof needs to be replaced, hail and wind are probably the  first things that come to mind. Because these events are called acts of nature, we think there is not much  that can be done to prevent damage from hail or high winds. The truth is quite different. While no roofing  system is “hail proof”, you can make your roof “hail resistant”. Insist on using a high density coverboard  when replacing or building a new roof. Insulation is soft and easily penetrated: think of foam board. But  coverboard adds a rigidity beneath the membrane that minimizes the impact of hail. We have seen roofs  that survived 3”-4” hail when coverboard was installed. Wind damage most commonly occurs at the  edges of a roof and can be minimized by using the right materials and installation techniques. 

Service Technicians 

Roofs are becoming more and more cluttered with mechanical equipment, solar panels, and  skylights. The real threat to roofs are the technicians who service this equipment. From the HVAC  technician replacing a filter or repairing a unit, to the maintenance worker who squeegees the solar  panels, a roof can get damaged because service people treat it as a work surface. They drop tools, they  drop covers, they roll carts across the roof. Even a simple thing like not properly securing an access  panel means that a high wind can take that loose panel and turn it into a knife cartwheeling across the  roof and slicing tears into the membrane. 

Three simple things will reduce the impact of technicians: install walkways and install them in a  direct line to equipment so they will be used; add walk pads around HVAC equipment to protect the roof  from a service technician’s tools; use coverboard to provide a hard surface beneath the membrane. 

Lack of Regular Maintenance

Have your roof professionally inspected on a regular basis. Catch small problems before they  become expensive repairs. Keep roofs clean from dirt, debris, and unnecessary equipment. If enough dirt  and debris build up on a roof surface, the owners can find themselves with an unintended rooftop garden  on their hands, and roots can cause damage to roofing materials. (And yes, we have seen this situation  multiple times). Keep nearby trees trimmed: branches can tear off and damage the roof, or leaves may accumulate in gutters or clog downspouts causing water to backup and stay on the roof. Remove  unwanted materials, cinder blocks, and old AC equipment. Our rule is “If it doesn’t belong up there, it  shouldn’t stay up there.” 

Design Issues 

Twenty to twenty-five percent of water intrusion problems on roofs are caused by design issues.  Some of these can only be addressed when doing a full roof replacement. However, many smaller issues  can be corrected. Any penetration (for example, an HVAC unit or a skylight) that is at least four feet  across and parallel to the roof edge, should have a cricket installed on the backside so that water flows  around the penetration instead of being trapped behind the penetration. Flashing details where the roof  meets a wall, expansion joints on larger roofs, and some edging details are all areas that can be  improved short of replacing the entire roof. 

The Bottom Line 

Because of design issues, installation techniques, and lack of proper maintenance, the average  roof lasts one quarter of the designed lifetime of a building. However, understanding and addressing the  underlying issues that prevent your roof from achieving its designed lifespan can add years to the life of  the roofing system.