It is understandable that people hate roof penetrations and try to avoid them at all cost. A commercial roofing system is expensive and the thought of poking holes in it sends shivers down one’s spine. But instead of simply avoiding roof penetrations altogether, consider that if done properly, those painful leaks can be eliminated and rooftop equipment can be mounted securely.
In fact, roofs are full of penetrations. Skylights, A/C units, air vents, and plumbing vents, to name a few, all involve roof penetrations. However, those instances aren’t usually problems because they are typically roofed in during new construction or renovation when properly designed by an architect or roof consultant, and installed by a qualified roofing contractor.
Leak problems occur when non-qualified contractors penetrate the roof with improperly designed attachments.
It is rare for a roofing system originally installed during construction or renovation to leak, assuming a reputable roofing contractor did the work. It is work that takes place after the roofers are gone that can create some real problems. An electrician runs a conduit through the roof, an HVAC contractor adds a small AC unit, an equipment screen gets installed; these are all common events with high potential for poor workmanship and resultant leaks.
When adding any type of equipment to a rooftop, primary concerns are safety, waterproofing and preserving the service life of the roofing. Using an inferior method of mounting equipment to avoid roof penetrations may solve the waterproofing concern, at least for the short term. However, adding heavy ballast, restricting water flow or leaving unattached equipment exposed to wind forces can seriously compromise building safety.
Roof penetrations are a good thing if you follow these two rules
Anything installed on a commercial roof that is subject to wind and seismic loading should penetrate the roof and mechanically attach to the roof structure. But don’t think of it as something you have to do, think of it as something you want to do in the same way that you want the roofing to last a long time and keep occupants dry and safe.
Rule #1: Have a qualified licensed roofing contractor do the roofing portion of the work.
Rule #2: Properly design the roof attachment.
It may seem counter-intuitive to say that roof penetrations are actually a good thing. But in almost all cases, properly designed and installed roof penetrations are exactly what you want. So next time you need to add equipment to a commercial roof, consult the experts at P.I. Roofing.