The Roof: Keeps the Home Dry
The roof is one of the most important structural elements of a home. A home inspector will evaluate the pitch (or slope) of a roof, its overall condition, as well as common risks associated with the type of roof that sits atop the home. An inspection will also assess other factors (such as nearby trees) that could impact the roof, and whether it appears leak-prone.
Most leaks result from improperly installed “flashing” – the material used to connect parts of a roof to other parts of the home (chimney, windows, adjoining garage structure, etc.). Flashing materials vary and are often different forms of metal. An inspector will check the look of the flashing to gauge whether the roof or its components are prone to leaks, as well as the condition of skylights and windows protruding from the roof.
Gutters and downspouts attached to roofs are also important elements of the roof structure. Improperly installed or clogged gutters won’t direct water away from the house properly and could distribute water near the home’s foundation, increasing the likelihood of basement flooding or foundation-related moisture problems.
Here’s an overview of the different types of roofing common in the United States:
Asphalt or composition shingles: Made of petroleum and other synthetic products, these shingles are the predominant type of roofing material in the US. They have an average lifespan of 15 to 30 years, depending on the roof’s slope, the type of shingle material used, and the regional climate. These roofs may deteriorate faster in hot, warm weather.
Roll roofing: This type of roofing is made of material similar to asphalt or composition shingles but is applied in rolls and is commonly found on roofs without only a slight slope. The lifespan on these roofs is often shorter than roofs made from other materials since roll roofing is built on a low slope.
Wood shingle or shake roofing: Wood shingles or “shakes” have varying life expectancy, depending on climate, the roof’s pitch, and drainage. These roofs are not as fire-retardant as others, but can be treated. Inspectors will also try and assess whether the wood roof has been laid in a manner that lets it dry properly.
Slate: Slate roofing is long-lasting and attractive, with the cheapest varieties estimated to last 45 to 60 years and higher-end types lasting for centuries. If your home has a slate roof, inspectors will look for white mineral deposits on slates, and also note whether or not slates need to be refastened or reinforced with nails or other fasteners. Crumbling slates or breakage can indicate that individual shingles need replacing – or the whole roof needs to be replaced.
Flat or built-up roofs: These roofs will need to be examined for standing or pooling water, which can create conditions conducive to moisture penetration. These roofs are usually referred to as “torchdowns” or “hotmopped” roofs.
Metal roofing: Metal roofing comes in a few different forms, including “standing seam” roofs which join several panels of roofing material and other forms of shingles and panels made from galvanized steel, treated aluminum or other materials. Metal roofs are often guaranteed to last up to 50 years, and they’re considered valuable because they are low-weight, low maintenance, and, if pitched properly, can successfully slough off snow and ice.
Tile roofing: Tile roofing, typically made from clay tiles, is common in warm and dry climates and is considered a high-quality roofing product in these regions.
The National Roofing Contractors Association provides a detailed guide to types of roofs and vocabulary on different parts of the roof: http://www.nrca.net/consumer/fyi.aspx