Inspecting Roofs

I wanted to visit this subject to help illuminate a few of the finer points of roof inspections as they relate to the overall home inspection. The first point home buyers need to understand is that none of the home inspection standards require the inspector to walk on the roof. This is a critical point since some inspection companies have a policy to NOT walk on a roof, either because of the weight or age of the inspector, or for other reasons.

At HomeTeam we always walk the roof unless there is some very specific safety reason that precludes it (snow, ice, rain, excessive pitch, etc). We walk the vast majority of roofs (probably 90 percent).

You may also hear of companies who use drones to “inspect” a roof from the air. As a former Air Force pilot, I looked at this option long before anybody was doing it, mostly because I thought it would be fun to fly the thing! But I concluded that the benefits are marginal at best, and at worst might give a false sense of security to the buyer. The fact is, there is no substitute for seeing the shingles up close, touching them if possible, and scrutinizing small details, none of which is available with a drone.

To give you an idea of what we look at when we are on a roof, it’s important to keep in mind two key objectives of our analysis: 1) does the roof require repair or replacement, and 2) what is the general condition of the roof, ie, will it need replacement now or in the near future?

To answer these questions, we look at several key areas. First, at the eaves we check to see if there is a metal drip edge under the shingles. The drip edge is designed to prevent rainwater from wicking up into the wood sheathing, and without it there may be underlying issues that are not visible from a “shingle-only” look. Next, we take a look at the shingle close up to identify any curling, brittleness, or excessive aggregate loss. Both of these conditions may indicate excessive age, or a roof that may be at or near the end of its life.

After that we look at nail pops, which are potential leakage points. Sometimes nails back themselves out of the sheathing and require repair. We check valleys and flashing to see if there are areas in which rainwater can penetrate to the interior, and we check all roof penetration points (plumbing vents, B-vents, etc) to ensure they are properly sealed.

In general, the first problems a roof typically has are at the roof penetration points, usually around the plumbing vents. The plumbing vents have something called a “flashing boot collar” that is a sort of rubberized material that fits snugly around the PVC plumbing vent. These collars tend to deteriorate, crack, and leak at around the 8-10 year point, so if your roof is that age, it is wise to have your flashing boot collars replaced. This is a relatively inexpensive repair that will save you lots of hassle and money if you do it proactively. Most people are not aware of flashing boot collar problems until they see water stains on the interior of their home, and at that point you may need drywall and other and more extensive repairs.

Some homes (typically older homes) have a lead cover instead of the rubberized flashing boot collar. These tend to last longer, but unfortunately they also fail, often due to squirrels nibbling at the sweet lead corners.

While we are on the roof we also look for signs of previous repairs and also evidence of a hail event and hail damage. Previous repairs are pretty easy to spot, and a hail event is usually visible on the soft metal parts such as B-vents. In short we look at a whole host of items to help us determine the overall condition of the roof.

I often also say that we inspect the roof from the inside since we take a look at it from the attic as well. Often the attic is the first indication we’ll see of leakage, either via staining or matted insulation from a previous leak.

By the way, roof leaks are usually at roof penetration points that can often be repaired without having to completely re-do the roof. Of course, with excessive wear and age, all roofs eventually need replacement. If that is the case, please do yourself a favor and hire a professional roofing company to do the replacement. We’ve seen ample evidence of shoddy work by fly-by-night roofing companies, and they never end well. Often these companies use substandard materials and will omit “small” details like flashing or drip edges that will lead to expensive and difficult repairs just a few years later.

The roof can be an expensive component to repair or replace, so make sure you hire a professional home inspection company to help you with your home purchase. You can always catch us here or email us at Please let me know if we can help!