Determining Roof Condition and Age

What is the condition of the roof ? That is an important question that you will want answered by your home inspection. Replacement of shingles is a big ticket expense that you will want to be able to plan for as much as possible. Ten-thousand dollar surprises are not fun, at least not when the money is going out instead of coming in. In addition to shingle condition, you will also want to know if the current condition of any of the roofing components are adversely affecting the structure.

A small leak at the chimney flashing, for example, can quickly cause damage to roof decking and framing leading to more repairs and expense. Condition issues may also include things that may lead to premature failure or impair functionality of the roof system. This may include improper installation practices, inadequate slope, incorrect materials, vegetation concerns, poor ventilation and so on. As you can see, properly assessing roof condition means inspecting not only the shingles but all of the roof components as well as considering any other factors affecting the roof system.

Determining the age of a shingled roof is essentially a way to approximate the remaining life of that component. Shingles have a life expectancy of thirty years for dimensional type and twenty years for three tab type. With that in mind, if the age of a dimensional shingle roof is estimated between ten to fifteen years old, then a fifteen to twenty year remaining life expectancy could be possible. However, do not assume that is a guarantee of performance but rather consider it as a best case scenario.
Roofs take a beating and often need to be re-shingled before the end of their declared life expectancy.
General weather conditions in our area typically reduce shingle life span by about five years. Other contributing factors, such as mentioned earlier, may further reduce shingles functional life span by several years. It is not entirely uncommon to see a thirty year shingle fail in twenty years and not unheard of to see them fail in fifteen years. Actual life of shingles will depend on all contributing variables over a given period of time.

Roofs are like people. Some don’t age well. This is why the information you receive from your inspector about the condition of your roof is so important. Every inspector has been in the situation where they reported a three tab shingled roof to be fifteen to twenty years old based on the condition, only to have a seller irately disputing the findings. Receipts in hand, the seller proves without a doubt that the roof was in fact re-shingled ten years before. Was the inspector wrong?
No. The age reported by the inspector is based on and reflects the actual condition at that time.
The installation date on a receipt at this time is largely irrelevant, other than to show evidence that other issues are likely present which are contributory to the premature failure of the roof.

What the seller failed to realize is that his inadequately ventilated attic and two layers of discount shingles installed by the cheapest out of state contractor he could find, were in fact, now effectively nearing the end of their useful life… Which is definitely useful information for you, the buyer!