As a home inspector in Nashville, Tn. I have conducted home inspections on many homes over the years either for insurance, or for a client purchasing a home. The one thing everyone is concerned with is how many years are left on the roof. As a home inspector in the Nashville area, we can’t give a specific number. We take into account many different factors and try to give you a range, while also explaining the various weather events or building issues, which may result in a shorter life of the roof.
One of the major issues which can affect the life of a roof is the attic ventilation. Installing proper ventilation in the attic is a key factor in the life of the roof, as well as preventing ice damming, and keeping your house cool during the summer. On one of my more recent inspections, I was on a newer home and my client needed an inspection prior to their one-year builder warranty expiring. On this home, my client had complained the air conditioning was not working properly during the summer. They also had no heat when the weather got cold and they needed someone to come out and turn the heat on. Now this says a lot about the builder’s quality control, but it also makes you wonder what’s wrong with the heating and cooling system and what did the installer do wrong? Well, my client had someone out in the fall to get the heat running and the technician said when the weather gets warm to have them back, so they can properly check the air conditioning. So as a home inspector, I generally defer to and rely on those who are licensed in their specific trade. So I agreed they should probably have someone out to do a maintenance check, since the trade professional said so. What I didn’t know was the results I would get when I tested the system as part of my normal inspection.
When I tested the system I paid great attention to all of the working parts and probably spent a little extra time looking at this system since the trade pro said my client needed it checked. I was looking for the issue. This was a zoned system with thermostats on both levels and the ability to heat or cool one or both levels at the same time. So I got the heat running and no problem was found. I then tested the air conditioning. To my surprise, there were no issues. I was reading a 16-18 degree temperature split at almost every register. I was a little confused, since the technician said they needed someone out when it was warm to fix the air conditioning. So I double checked everything, and well you guessed it, the problem was not with the heating and cooling it was in the roof venting or lack thereof. The heating and cooling units in the Nashville, Tn. are commonly placed in the attic. Placing these units in the attic is a whole other issue, so let’s stay on topic. The unit was in an unvented attic. The lack of ridge venting in this particular attic was causing extreme temperatures in the attic in the summer and the cooling system could not keep up.
My clients wouldn’t sleep upstairs in their brand new home during the hot summer nights because the house wouldn’t cool down. Now, it wasn’t an extremely hot day, so I couldn’t get a temperature reading in the attic on this particular house, but other attics I have inspected with similar lack of venting issues had temperatures in excess of 150 degrees Fahrenheit. These high temperatures lead to deteriorated plywood, shortened life span of shingles and in my opinion broken trusses. So, improperly vented attics lead not only to hot homes, but shortened lives of roofing materials and if your heating and cooling systems are installed in the unvented attic, it may not be able to cool house.
Here is a great link to an article about ridge venting by Fine Home Building