Roof Inspections

A roof inspection is a vital portion of the home inspection process due to its sheer size, water-resistant features, and high cost of replacement. An issue within the roof structure may not be obvious to the casual observer, and moisture intrusion can often go unseen for months or years causing significant structural damage to other parts of the dwelling. The primary function of a home's roof is to effectively shed water off of and away from the structure(in a joint effort with its flashing effects, gutters, and downspouts). Lets start at the very top with the roof covering!

The most common type of roof covering on a residential property is the asphalt shingle(sometimes referred to as 3-tab shingle or composition shingle). An asphalt shingle is comprised of an asphalt covered fiberglass mat that gives shingles their strength to resist splitting, tearing, and pulling through the heads of fasteners. Fiberglass shingles deform less than their organic predecessors because fiberglass(in a newer, functional shingle) does not absorb moisture. This mat is coated with surface material called granules, which are generally small crushed-up rocks. The granules serve some very important purposes! They reflect sunlight which helps protect the shingle from UV damage and loss of volatiles(the compounds that keep the shingle from becoming brittle and absorbant). They add weight to the shingle which helps the adhesive strips bond more thoroughly(protecting your roof from wind damage). They make shingles more durable by protecting them from weathering and abrasion, and lastly, they improve your roofs fire resistance! Asphalt shingles come in various thicknesses and quality, and can be expected to last 15-50 years based on the quality of the shingle(most commonly 20-30 years). An asphalt shingle begins wearing the moment it is packaged, and that wear accelerates after it is installed until it reaches a point where it surpasses its useful service life at which point the wear decelerates.

You can clearly see a more weathered, low-slope section of this roof in comparison to the steeper pitch

Why is this information important to the homebuyer?

As asphalt shingles naturally weather they become more brittle and absorbant which can retain moisture against the underlayment and ultimately roof sheathing(or decking), which is usually comprised of plywood, or oriented-strand board(OSB). The longer moisture is retained against a structure the better the chance it will find its way inside! A worn roof covering will not always be obvious to the naked eye, making it all the more crucial you hire an inspector who will climb a roof, and know what he/she is looking at! Another factor in the wearing of shingles is poorly ventilated attic space. This will cause more heat to build up in the space below the roof, heating the shingles up hotter than normal. This will usually show up on a roof as blistering, a condition where volatiles rapidly burst through the granules causing a small circular area of the mat to be exposed. Lets take a look:

"Blister Pops" caused by poor ventilation.

Impact/Abrasion Damage is also common:

Abrasion Damage

So are "nail pops", where the mat weakens enough the pull through the attaching nails:

"Nail Pops" are commonly covered with sealant. Which only prevents moisture intrusion as long as the sealant lasts. This is only a temporary repair and a common source of roof leaks.

These are only a few examples of issues found with asphalt shingles and their installation. All of these issues can eventually lead to water intrusion into the roof decking and beyond, potentially costing a homebuyer 10s of thousands of dollars in repairs.

When purchasing your next home(or selling it) make sure you hire an inspector who knows what to look for in a roof assembly! We have numerous InterNACHI and CCPIA certificates and continuing education hours pertaining to the roof structure! Give us a call today to book your residential or commercial inspection! #havemooktakealook