Got inspection questions about roofs? We have answers. Roofs do more than just shield a house from the rain. They’re complex systems with many different types of roofing materials, and they can affect the integrity of the whole house that sits under them.
What Types of Roofs Might You Find on the Job?
Although the classic roof image of a roof has a central peak and two sloping sides, that open or box gable style is only one type of roof of many that are common in American homes. Here’s a short list of roof styles you might find on the job:
You’ll find combinations of those styles, too. For example, gable-style roofs often have a dormer, which is a window that juts out from the roofline and has a small roof of its own. Elaborate Victorian homes might incorporate several roof styles in one.
Some roof types are more common in certain parts of the country. The flat roofs of the South are uncommon in residential property up north because they can’t support heavy snowfall. But a steeply pitched roof is right at home where winter weather increases the roof load.
How are Most Roofs Built?
A roof system begins with the trusses. They create the solid framework that supports the roofing material. But the trusses also affect the rest of the house. If they’re unstable or damaged, the whole house can suffer.
Sheathing is the next layer. Typically OSB or plywood, it’s the flat, durable surface that’s anchored to the trusses. If there’s a roof leak, the sheathing can warp, buckle or even rot.
Above that is the roofing underlayment. Water-resistant builder’s felt or another material, depending on local code, this layer is usually present in newer homes. But DIY Network says it might be absent with older construction.
Roofing materials are installed over the underlayment. Asphalt shingles are by and large the most common in America. But there are lots of others. You might encounter tiles made of clay or slate, wood shingles, metal panels and even rolled rubber or rubber tiles. Flat roofs are an entirely different type of system that you’ll learn about, too.
What are Some Common Roof Defects?
Most residential roofs have a lot more than just the sheathing, underlayment and roofing shingles, panels or tiles. You might find chimneys, plumbing vents, attic vents, soffit vents, turbine roof vents and a host of gutting and downspouts. Every feature that penetrates or anchors to the roof is a potential leak.
CertaRoof says the most common roof defects include:
- Improper roofing installation
- Improper repairs
- Poor or improperly installed flashing
- Missing or deteriorated sealant around roof penetrations
- Damage from storms, impacts or anchors for antennas or other equipment
- Exposed or missing nails
- Debris buildup (including debris in valleys and gutters)
- Damaged ridge caps
- Damaged or missing vent caps
- Cracked or unsealed skylights
- Exposed underlayment
Every point where water can reach the roof sheathing is a defect. And improper installation of roofing, guttering or roof penetrations can leave the entire roof system vulnerable.
Roofs are much more than shingles or tiles. They’re complex systems, and they can also be health indicators for the whole house.
Icicles and ice dams in winter indicate poor ventilation, inadequate insulation or both. One tiny roof leak can cause widespread structural rot. Moss build-up in valleys can lift and break apart roofing materials over time. And gutters filled with debris can let water backwash under shingles, flood the sheathing and leak inside the home.
The roof is one of a home’s first lines of defense against the elements. Like siding, it protects the structure from wind, impacts, and bad weather. And it helps the people who live there feel more comfortable.
Once you complete your ICA School home inspection training, you’ll have a strong working knowledge of these intricate systems, how they function and how to spot minor and major defects. Enroll now and let’s get started!