Subrogating Residential Asphalt Shingle Wind Losses - Know This FIRST!

While there’s plenty to pursue, subrogation in residential roofing wind losses remains relatively uncommon and difficult.  However, under the right circumstances, it isn’t impossible.  In fact, by applying a few common sense rules, chances of successful subrogation are very good.  Here’s some ideas on the subject worthy of consideration.

1. Don’t waste your time if the shingles were installed more than 5 years ago.  Nobody will likely carry any liability, regardless of the scope of the loss.  The newer the roof, the better your odds.
2. Don’t pursue it unless the loss is significant.  In losses of a few thousand dollars or less, you’ll invest more chasing it than the loss is worth.
3. Be certain before you pursue a manufacturer.  Successful subrogation against a shingle manufacturer requires a thorough investigation.  Know that and be prepared for it before you begin the pursuit.
4. Contractors may have much to do with wind losses on new roofs, yet they operate in an extremely “high turnover” industry, so they need to be identified before your pursuit is worthwhile, regardless of the size of the loss.

Still want to go for it?  Now you need to know something about the roof’s performance expectations versus how it actually performed (or failed to perform, depending on your perspective).  For insight here, we’ll look to the 2003 International Residential Code (“code”).

Consideration 1

Per the code (Section R905.2.6), "Shingles classified using ASTM D 3161 are acceptable for use in wind zones less than 110 mph."

What does this mean?

In order for asphalt shingles to pass the ASTM D 3161 test, asphalt shingle test panels that measure 50 inches (1.3 m) wide by 66 inches (1.7 m) long are subjected to sustained fan-induced wind speeds of 60 mph (27 m/s) for two hours. A test panel assembly is considered to have passed the test when the full shingle tabs are restrained from lifting or the locking ears (e.g., interlocking shingles) are not torn loose or disengaged during the test.

This assumes:

1. They're properly installed.
2. They're properly sealed.
3. They contain no defects.
4. They've been handled properly.
5. The roof is perfectly flat, without, ridges, valleys, etc.
6. Wind always blows at a smooth and constant speed.
7. Weathering is not relevant.
8. Etc., etc.

Regardless of these significant issues, the reality is that most shingles we encounter do meet ASTM D 3161, and therefore meet the code's criteria for being a suitable product.

Consideration 2

Regardless of Rule 1, if a roof suffers any significant failure at wind speeds below 60 miles per hour (mph) and is five years old or less, potential subrogation is a worthwhile conversation. We therefore routinely refer to 60 mph as being the threshold for a wind speed to be classified as "severe." Winds below 60 mph may be strong and unfortunately damage roofs all too frequently, but a roof should be designed and built to sustain frequent winds below this speed and not be damaged, unless the roof is failing from causes unrelated to wind.

Consideration 3

Wind affects roofs in some areas more than others. Be on the lookout for wind failures in the areas where wind has the least influence. Where are these areas? Again, the code clearly illustrates areas of concern as shown in the following illustrations, taken from the code.

Figure 1

Figure 2

Figure 3

Of interest, note the numbers 1, 2, and 3 inside the circles in the above illustrations which indicate common "zones" of exposure on the roofs. These zones refer to areas where wind exerts comparatively more pressure, either downward or upward, on the roof as it passes over the roof surface. The effects of wind are strongest in Zone 3 on each roof, and least in Zone 1. As a result, be on the lookout for the claim where damages are located in Zone 1, but not in Zones 2 or 3 where a roof is naturally more prone to damage.

Feel free to call and speak to a Donan engineer for more information on residential roofing forensics, or for any forensic engineering, fire investigation, vehicle accident reconstruction, or appliance and component testing. Whether you retain our services or not, we're here to help.