Roofing 101

We at Dwell Inspect Arizona would like to give you professional insight into the home inspection process. With a greater understanding of how the home inspection is conducted and reported, you can better interpret the report presented to you and your client. As a professional and knowledgeable agent, you can be better prepared for the negotiating period following the inspection.

“How am I going to live today, in order to create the tomorrow I’m committed to?”

— Tony Robbins

When purchasing a home it is important to understand the material of the roofing and it expected lifetime. Additionally, it is beneficial know if there are preventive steps that can be taken to extend the life of the roof. A qualified and professional home inspector can evaluate both the condition of the roof covering and it surroundings to determine a future plan of action.

It is inevitable that roof coverings will deteriorate over time because natural elements are all working together to degrade the condition of the roof. The sun deteriorates organic ingredients in roofing materials, it heats and cools materials causing expansion and contraction, and it dehydrates the roof coverings causing it to show conditions of wear. Rain is just as detrimental, over time the water penetration washes away the protective qualities of the roof. The wind affects the functionality of the roof by blowing shingles off the roof, or when paired with the rain, it could force moisture underneath the shingles allowing water into the house. Additionally, landscaping, such as trees, can cause physical damage to a roof by the branches scraping across the installed coverings. In some scenarios, the tree could provide too much shade, which would not allow the roof to properly dry after a rain increasing the potential for destruction. Unfortunately, every element is working together to attack the condition of a home’s roof and it is only a factor of time before replacement would need to occur. With the understanding of the materials an informed homeowner can properly budget for repairs and replacement. 

There are many different types of roof covering that exist, but there are four types that are commonly seen in Hawaii: asphalt shingles, roll roofing, wood shingles/shakes, and clay tiles.

Asphalt shingles

Are made of asphalt-impregnated felted mat of cellulose or glass fibers which is coated with another asphalt formulation and covered with a granular material. This is currently the most commonly used material in roofing. A life expectancy of an asphalt shingled roof is between 15-25 years depending on the quality of the shingles chosen and the effecting elements.

Roll roofing

Made from the same material as asphalt shingles and it generally comes on 36” rolls. Quality of this product varies greatly and it is generally applied to roofs with lower or flatter slopes. Roll roofing is an inexpensive option and generally has a life expectancy of 5 - 10 years. 

Wood shingles/shakes

Pieces of wood that are cut and layered  to make a roof covering. With proper maintenance of a wood shingle/shake roof the life expectancy can be in the range of 50 years.        

Clay/Concrete tiles

Heavy, long lasting, weather resistant, and fireproof. A typical clay tile roof can be 4 to 5 times heavier than an asphalt roof and therefore will require additional load bearing structure. Tile roofs have a life expectancy of between 20 - 50 years but have been know to last 100 years depending on the quality of the tile, installation, and underlayment.