Staying Aware of the Potential Pitfalls of Internal Gutters
by Trent Cotney, partner, Adams & Reese, LLP
(Editor’s Note: Trent Cotney, partner at Adams & Reese, LLP, is dedicated to representing the roofing and construction industries. Cotney is General Counsel for the Western States Roofing Contractors Association and several other industry associations. For more information, contact the author at (866) 303-5868 or go to www.adamsandreese.com.)
As you no doubt know, gutters can be both external and internal. Some customers may prefer an internal system for aesthetic reasons. However, before you agree to that, remember that the main difference between external and internal gutters is what to expect when they fail.
Considering Gutter Failure
Gutters can be compromised after overly heavy rainfall, when debris clogs a downspout, or for other reasons.
An external gutter is usually installed along the lower end of a roof, positioned outside the structure’s footprint. Downspouts are connected and ensure water flowing into the gutter will drain outside. When this type of gutter fails, water will deposit outdoors.
An internal gutter has a different setup. To adequately function, it funnels water through troughs that appear throughout the roofing system. The troughs allow water to drain into tubes that appear inside the building. So, when an internal gutter malfunctions, water ends up indoors.
Why Internal Gutters Are Installed
Internal are not as rare as some may believe them to be. They are often used with flat roofs and sometimes with metal roofs. Commonly, they are necessary for a building that is not designed to accommodate external gutters or when designers and owners opt to avoid the appearance of external gutters.
Downfalls of Internal Gutters
Although some designers and owners may prefer internal gutters, there are many reasons to avoid them. When these gutters fail, water can be deposited inside the building envelope. That can result in severe damage to the building and present hazards for people who live or work there. Water can ruin materials inside the building, lead to the growth of mold, and cause occupants to slip and fall. In addition, water can do lasting harm to insulation and the entire roofing system.
In addition, if an internal gutter does fail or is damaged in any way, repairing or replacing it can be challenging. Often, internal gutter systems are installed under roofing materials, which must be removed to provide access. Owners sometimes have to replace fully functioning roof systems so the internal gutters can be repaired or replaced. This issue is even drastic for a metal roof, which should have a long 50 or 60 year life.
Accommodating Internal Gutters
If you must install an internal gutter, do your homework and minimize your risk. Discuss the pros and cons of internal gutters with the designers and owners. Explain the potential problems. Make sure internal gutters are made of stainless steel or other long-lasting materials. In colder climates, ensure that a snow guard system is installed. Be sure that internal gutters have a continuous support structure, perhaps made of plywood, for more stability. Ensure that your contract includes language about the internal gutter and its limitations. Include stipulations that protect you from risk if the gutter system fails and there is interior water damage.
Although internal gutters may be more aesthetically pleasing, there is a higher risk of water intrusion associated with their installation and use. As a result, be sure to have numerous discussions with the owner and document any recommendations to mitigate the risk if the owner insists on an internal gutter system.