10 reasons roofs should be inspected
Roofs are often said to be like tires. We only think of them when a problem arises, and we only replace them when we absolutely must. But, when we do think of tires and maintain them regularly, we can extend their useful lives. Similarly, we need to ensure that the roof receives the proper maintenance to increase its useful life.
Extending roof life starts with regular inspections. The National Roofing Contractors Association recommends inspecting all roofs twice a year: once after the coldest weather, once after the hottest weather. (And it’s always a good idea to inspect the roof following any major weather event.) But why should roofs be inspected, and what do we hope to discover by doing so?
All roofs should be inspected whether they are low slope roofs or steep roofs. A low slope roof is one with a slope of less than 3:12 whereas a roof with a slope greater than 3:12 is considered to be a steep roof. All low slope roofs should have at least 2 percent slope, which is approximately 1⁄4-inch per foot.
What follows are ten pieces of advices — or the ten most common reasons — to inspect roofs at least twice per year.
1. Weathering and Aging
The benchmark life for multi-ply bituminous low-slope roofs is 20 to 30 years and approximately 15 to 25 years for most single-ply roofs. All roofs undergo normal weathering and aging, and the effects of those factors are usually visible. As roofs weather and age normally, openings may occur, leading to water infiltration. Regular inspections call attention to weathered areas and enable an owner to schedule maintenance on these deficiencies to prevent further damage.
2. Routine Maintenance Damage
If your roof is not protected properly, damage can occur from tradespeople performing maintenance on air conditioners and other systems. This sometimes occurs because of trades failing to close mechanical access panels on roofs or leaving refrigerant containers. In addition, maintenance trades often fail to clean up their debris. Items left on roofs can become flying objects in high winds. A regular inspection program incorporates roof cleaning into the ongoing maintenance cycle.
3. Storm Damage
High winds, hail, and other weather events can create damage to roofs that may trigger repairs or insurance claims. Roofs should be inspected immediately following weather events to prevent further damage due to water infiltration. Damage from winds or hail can be slight and require little more than minor maintenance, or the problems can be major and require roof replacement. Insurance loss adjusters have reported that a significant amount of storm damage is actually caused by material, components, or debris blown from roofs in high winds. Tree limbs and branches can fall on roofs creating significant damage. Roof blow-offs start at the perimeter, and when roofs are not properly designed or installed to provide proper perimeter securement, severe damage can occur. Storm damage may require emergency repairs costing even more money.
4. Leak Assessment
Leaks after heavy rain are the primary trigger for most inspections. But a leak is only symptomatic of a problem that may have been building for some time. In some cases, if you're looking for a silver lining, a leak is actually good news. That's because without evidence of a roof leak, a festering problem of undetected moisture infiltration may continue to create unseen deterioration, such as rotting wood, mold, wet insulation, or corrosion.
It takes an experienced professional to conduct a thorough leak investigation and diagnosis, because the entry point for moisture may be far away from the visual evidence or detection point. Leaks can be evidence of serious roof problems or minor local issues. Many roofs in excellent condition occasionally have leaks due to minor flashing problems.
As a general rule, low slope roofs rarely leak in the open field of the roof. Leaks tend to occur around discontinuities, such as changes in elevation, penetrations, expansion joints, and flashings. On the other hand, severely deteriorated roofs may not show visible evidence of leakage, particularly over concrete decks where water may migrate a great distance before reaching an entry point through the concrete. When such a condition occurs, damage due to moisture saturation of the roof insulation may be so significant that the roof must be replaced.
5. Proper Drainage
Few characteristics are as important to roof performance as roof slope and drainage. Water standing on a roof increases the likelihood of leaks and moisture infiltration many-fold. Ensuring good drainage is a very important reason for regular roof inspections. Leaves, trash, debris, and thrown objects often clog or obstruct roof drains, thus creating standing water conditions. Regular cleaning of roofs can help remove such obstructions and permit water to drain efficiently, thereby reducing the likelihood of leaks. Moreover, water is heavy — weighing approximately 5 pounds per square foot per inch deep. Poor drainage also accelerates deterioration of roofing materials, leading to a shorter life of the entire roof assembly. If a leak occurs from standing water, insulation can become saturated over a wide area, requiring complete roof replacement.
6. Vegetation Damage
Vegetation can grow on roofs when gutters and other low areas are not cleaned regularly. Birds land and nest on roofs. They also deposit seeds, which promote the growth of vegetation. Gutters are a particular source of vegetation growth because of the accumulation of dirt, seeds, and moisture. In addition, tree branches scraping on roofs during wind can cause significant damage. Gutters should be cleaned regularly, and trees near roofs should be trimmed to prevent contact with roof surfaces.
A further problem with vegetation growth is that roots can penetrate through the roof membrane and create leakage. Root damage to roofs from vegetation can be significant and pervasive. Regular inspection can help draw an owner's attention to a budding problem before further damage is done.
7. Roof Cleaning
Regular roof inspections also draw attention to the need for regular roof cleaning. No task can provide a better payback than the low-cost practice of cleaning trash and debris from the roof. A clean roof is less likely to have wind damage. Loose trash and debris not only may cause wind damage in a storm, but trash tends to wash to the low points at drains or gutters. Trash obstructs proper roof drainage and creates leak problems that would otherwise not exist.
Thieves often break into buildings through unlocked roof hatches or skylights. Regular inspections can disclose security breaches and enable owners to reduce the likelihood of vandalism or burglary. While a broken skylight is likely to be a source of water leakage, unsecured skylights can also present a security threat.
9. Warranty Repairs
Many owners pay for repairs that are covered under a contractor or manufacturer's roof warranty. Leaks can be caused by many factors, only some of which are covered under a roof warranty. However, when a leak is detected, an owner should have a qualified person perform an inspection to determine whether or not to file a warranty claim. When a roof warranty claim is filed, the contractor or manufacturer will visit the site and make a determination whether the leak or repair is covered. The key for the owner is maintaining possession and ready access to the warranty document, as well as timely filing of the claim.
10. Needed Improvements
Regular inspections highlight the need for continual building improvements, many of which affect the roof. For example, the increased presence of electronic equipment, computers, security systems, and video displays has encouraged many owners to install lightning protection on older buildings.
Roof access is an important provision for all buildings. It is well known in the industry that roofs that are accessible are maintained while roofs that are difficult to access are ignored. Regular inspections are facilitated with improved safe access to roofs. Installing permanent ladders and safety rails around roof hatches greatly facilitates safe access to roofs.
Establishing a schedule for routine roof inspections should be a priority for building owners. Inspections are inexpensive and can provide valuable information that can prevent expensive repairs later. In addition, regular roof inspections provide a checklist for routine maintenance work and enable owners to prepare budgets for future years. Roof inspections are the first step in a proactive roof management program that can help owners have planned and scheduled repairs instead of emergency leak repairs. Few other building maintenance procedures provide a better return on investment than regular roof inspections.
Edis Oliver, PE, is a principal in the Austin, Texas office of Wiss, Janney, Elstner Associates, Inc. He is a nationally recognized roofing expert with more than 40 years of experience in the construction and engineering field. Oliver was selected by the Roofing Contractors Association of Texas to write the roofing contractor certification manual, titled "Managing a Roofing Company in Texas."