Functional hail damage, the level of hail damage that is considered to require replacement, is immediately detectible by one who is properly trained and experienced in the identification of functional damage.  Industry studies and publications independent of those with a vested financial interest, such as shingle manufactures and individual roofers, have defined functional hail damage to asphalt shingle roofs as a diminution of the water shedding ability of the shingle or the reduction in the long-term service life of the shingle.  This definition is based upon many years of research and testing and has been published in peer-reviewed literature.

Functional hail damage to asphalt shingle roofs is characterized by localized loss of granules, usually circular in shape, accompanied by a fracture in the mat.  A fracture in the mat is evidenced by a visible relatively clean fracture, an indentation in the mat of the shingle, and/or localized softness felt in the mat.  Industry studies have shown that softness at a spot in the mat, commonly called a bruise, is indicative of a fracture on the bottom side of the shingle or within the mat.  Hail damage can be detected immediately after the hail impact either by visual observation and/or by tactile examination of the shingles.

The loss of granules alone, is not considered functional damage, especially the gradual loss of granules over time.  Granule loss may be evidenced by granules in the gutter, a widespread and relatively uniform loss of granules on the shingles, or spots of localized areas of granule loss.  These conditions are better explained by other causes that are considered normal wear and tear or premature aging.  In situ studies by Haag Engineering of Dallas, Texas have shown that granule loss from hail impacts, which do not fracture the mat, does not affect the long-term service life of the shingles. Granules are commonly dislodged and are expected to be dislodged when the shingles are exposed to heavy rainfall, wind, small hail impacts, and normal foot traffic.

Some have proposed that granule loss from hail impact can appear days, weeks, months, and even years after the hail storm and result in premature aging.  However, the progression of granule loss described in this proposition is considered normal wear and tear.

Shingle manufacturers sometimes promote this proposition saying that there is no way to be sure of the long term effects of hail impacts.  Acceptance of this proposition by the shingle manufacturers allows them to consider nearly all shingle material warrantees to be void after a roof has been exposed to impacts by any sized hail.  This would be nearly every roof.  We have seen some manufacturer’s go above and beyond their responsibility with regard to warrantee coverage of product defects, however, it is our opinion that this proposition sometimes allows a convenient way of avoiding responsibility for product defects.

NW Jefferson, Ashtabula County, 1- 1/4 inches reported by the public

Ashtabula, Ashtabula County, 7/8 inches reported by the public

North Youngstown, Mahoning County, 1 inch reported by the public

Medina, Medina County, 3/4 to 1 inch reported by the public

Richland, Shelby County, 1 inch reported by a trained spotter

Navarre, Stark County, 1 inch reported by the public

East Warren, Trumbull County, 3/4 inch reported by a trained spotter

Cortland, Vienna, Trumbull County, 1 inch reported by the public

Vienna, Trumbull County, 3/4 inch reported by a trained spotter and an airplane pilot

Hubbard, Trumbull County, 1 to 1-1/4 inches reported by the public

The sizes of the reported hail have not been verified by the NWS.  These are reports by the witness categories listed.   Our experience has taught us that the actual size experienced has often times been smaller than what has been reported.

The size of the hail at a particular site may be estimated after the storm by the review of eyewitness photographs and/or videos of the hail (preferable with a common object that can provide a scale for the size), the size of the indentations in deformable materials such as metal flashings, the size of the splash or spatter marks on exposed surfaces, the size of indentations on wood surfaces, the size of indentations on the metal fins of an air conditioner, etc.

The sizes reported are capable of indenting some light gauge metal building components and may be capable of damaging some composite asphalt shingles.  Visual and tactile examination of the shingles and metals by trained and experienced personal can determine whether or not there has been functional hail damage to these.

Composite Asphalt Shingles

The use of asphalt shingles began in the early 20th Century with the cutting of roll roofing into smaller pieces to mimic shakes or slate.  Asphalt shingles have been basically comprised of a mat encased in asphalt and a topside covered with ceramic granules.  The mat provides the base or structure of the shingle.  It is coated with asphalt to provide water shedding ability and covered with granules on the topside to reduce damage from foot traffic and degradation of the asphalt by the sunlight.  See Figure SDE-1.

Figure SDE-1 A typical three-tab shingle.

The basic construction of a shingle has varied little over the past century due to advances in the materials.  There are now also different types of shingles that offer a variation in appearance, durability, strength, wind resistance, etc.  The asphalt shingles commonly found on roofs today have an organic mat or a fiberglass mat.

The mat of an organic shingle is comprised of a cellulose fiber made from wood, recycled rags, and/or recycled paper. For those of us who remember the good old days of kindergarten, an organic mat looks and feels similar to the thick construction paper that we used for our art projects, except it is thicker and stronger.  The organic mat is first saturated with asphalt.  The asphalt provides some strength and flexibility, and promotes water shedding on a pitched roof.  The granules on an organic mat are bonded to the asphalt encased mat with a second layer of asphalt coating (the flaking of the second coat may be seen in Figure SDE-2).  Shingles with an organic shingle mat were the most popular prior to 1980.

Figure SDE-2 Flaking of granules and bond coat exposes asphalt mat below.

Since about 1980, fiberglass shingles have become more common.  The mat of these is comprised of a fiberglass weave. The fiberglass mat is soaked with one coating of asphalt and covered immediately with granules.   Since asphalt does not bond well to fiberglass, the fiberglass mat must be coated with a bonding agent prior to being soaked with asphalt.  Since there is only one coating of asphalt during fabrication, a fiberglass mat shingle is usually thinner and lighter than an equivalent organic mat shingle.

Figure SDE-2 Fiberglass mat. Note fibers encased in asphalt.

The most commonly used shingle is the three-tab shingle (Figure SDE-1).  There are also shingles with a laminate or an appliqué to produce a thicker or decorative appearance.  A laminate shingle is comprised of two narrow strips of shingle that are bonded together, see Figures SDE-3 & 4.  This construction gives a more three‐dimensional appearance to the shingle.

Figure SDE-3 Laminate shingle construction shown in a sketch.

Figure SDE-4 Laminate shingle.

A three‐dimensional appearance may also be accomplished by adding a second coating of asphalt and granules, commonly called an appliqué, over a portion of the shingle already covered with asphalt and granules. This is similar to the application of an appliqué on a T‐shirt. The appliqué method results in a greater thickness of asphalt over some portions of the shingle (Figure SDE-5). And like the appliqué on a cheaper T-shirt, it often degrades easily, cracks, and peels.

Figure SDE-5 Appliqué shingle in service. Note that a second layer of asphalt was added for a raised layer of granules.

When composite asphalt shingles are new they are relatively soft and flexible.  The soft and flexible shingles are usually able to accommodate the thermal movement during temperature changes, both from within and from adjacent components, and vertical or horizontal roof movements during snow and wind loading.  They are also more resist to damage from impact by hard objects, such as hail stones.  As asphalt shingles age, they lose softness and flexibility.  The loss of softness and flexibility reduces their ability to accommodate thermal movements and impacts.

For more information about shingle manufacturing, visit the GAF website or watch the GAF shingle manufacturing process video or visit the website of another shingle manufacturer.  Our referencing of GAF is not necessarily an endorsement of them or their products, recommendations, opinions (especially with regard to their technical bulletin regarding hail damage), corporate stand on any issues, etc., but we thank them for providing technical information helpful for learning about the manufacture and installation of their products.

The next topic will be the Effects of Aging on Composite Asphalt Shingles.

According to a report from the Structural Building Components Association regarding the April 18, 2012 meeting of the American Lumber Standards Committee (ALSC) Board of Review, “Douglas Fir Larch testing is on-going and scheduled for submission to ALSC in September of 2012. DFL is being tested first; then testing will be performed on Hem Fir and SPF-South.”  And, the “Southern Pine Inspection Bureau (SPIB) will not have data submitted for these prior to July 2012.”

The lumber organizations appear to be proceeding cautiously with this issue in the interest of public safety, but also to avoid reducing design values excessively.  In the meantime, the Southern Yellow Pine lumber related industries are dealing with the dilemma of what design values to use in the interim.  They don’t want to provide unsafe products, but also do not want to be fabricating their products with excessive amounts of lumber.

Stay tuned, I am sure that more will be coming.  Our thanks to the Structural Building Components Association for keeping on top of this issue for us.

Introduction

There have been numerous storms with hail that have passed through Northeast Ohio, especially since 2003.  At Prugar Consulting, Inc., we have had the opportunity to examine hundreds of shingle roof surfaces, roof vents, gutters, siding, trim coverings, etc. that have been exposed to these storms.  We have observed and documented damage to shingle roofs and other exterior building components that were caused by hail, wind, and other storm related damage producing mechanisms.  We have also observed flaking, cracking, clawing, wear, etc. on older roofs that have served well‐beyond their expected service life; shingle defects that were mistaken for hail damage; mechanical damage applied in a systematic fashion (intentionally); random mechanical damage applied during installation or later roof maintenance; dislodging of granules from lichen growth and bird‐droppings; damage from poor installation of the shingles; etc.

So how does one evaluate the cause(s) of damage to a shingle roof and its related components?  A proper evaluation begins by familiarity with the materials that comprise a composite asphalt shingle and its related components, an understanding of proper installation, and an accurate understanding of the characteristics and features of the damage caused by various damage producing mechanisms.  The application of these coupled with in-the-field experience of verifiable shingle damage leads to an accurate and true assessment of the cause of damage to the shingles.

The components of a composite asphalt shingle may be better understood by reviewing the information on the websites of various shingle manufacturer’s, attending shingle roof seminars, viewing the manufacturing process, etc.  Many of the manufacturers are pleased to describe the properties of the components that distinguish their product from another.  Some even describe the process of manufacturing or provide a video of their process.  Shingle manufacturers are also pleased to provide information regarding proper installation of their products.   Hands on experience such as, visual and tactile examination of different styles and brands of composite shingles is also helpful in being familiar with composite asphalt shingles.  The installing and repairing of shingle roofs provide additional insight regarding the properties of shingles and the damage producing mechanisms they are exposed to during installation.

The known and documented characteristics and features of various causes of shingle damage are found in industry publications.  These provide a criteria for the assessment of various damages to composite asphalt shingles.  These criteria are based on industry experience and laboratory testing.

Our next post will discuss the materials that comprise a common composite asphalt shingle.  In subsequent posts we plan to discuss the installation of shingles and the characteristics and features of various damages to them.

Local news media reported that a large tree fell onto a house in Cleveland Heights, a utility pole was leaning from the wind in Warrensville Heights, and waves were blown onto the Shoreway.  I noticed numerous branches down in North Royalton and Middleburg Heights.  My Mom even emailed a photo of a fallen light pole on York Road from her iPhone.

Roof leaks generally exhibit a pattern of wetness or water damage, such as wetness, staining or decay, that emanate from a specific location.  If the pattern of wetness or decay does not emanate from one or few specific locations and some type of breach in the roof system cannot be found, the wetness and subsequent damage are probably not due to a roof leak.

On occasion we have identified the wetness around a chimney to be due to the condensation of the airborne moisture in the exhaust gases discharged by the furnace on the cold chimney walls.  The wetness on the outside faces of the chimney occurs when the condensate migrates through the mortar.  Condensation of exhaust gases are evidenced or accompanied by one or more of the following:

• The pattern of wetness is relatively uniform on all the sides of the chimney exposed in the attic.
• The wetness is more severe at the basement and/or the first floor than the second floor or the roof.
• White and tan mineral deposits on the surface of the chimney, plaster, or drywall.
• Mortar, plaster, drywall, etc. deterioration from exposure to the acidic condensate.
• Missing, cracked, or separated flue liner.
• Exhaust gases in the chimney are from a higher efficiency, non-condensing furnace (usually 85% plus).
• Excessive corrosion exhibited on metal imbedded in or in contact with the chimney.
• Higher than normal relative humidity in the dwelling, especially during winter months.
• The chimney only “leaks” during the cold weather seasons.

When a number of these characteristics are found, consider that the wetness and subsequent damage on and around the chimney may be due to the condensation of the exhaust gases and the migration of the condensate through the mortar.

This issue may be addressed by replacing the furnace with one that exhausts through a wall, thus, not introducing exhaust gases into the chimney or by the installation of a non-corrosive flue liner.  Contact a qualified and experienced heating contractor for more ideas.

When the new posts have been completed, the article will also be available in one article again.

Thank you for your patience with our updating.

One friend reported minor wind damage to some poorly installed trim and a loose pane of glass at his home in Olmsted Township, but I did not find any local reports of major wind damage.  (If you know otherwise, please email me, thanks).  Winds of these speeds are not expected to damage reasonably well-maintained exterior finishes of a building such as shingles or siding.

Mid-term weather forecasts by climatologists indicate that late spring and early summer will be wetter than normal.

A statement released on April 2, 2012 states that the American Lumber Standard Committee (ALSC) Board of Review  has approved changes to the design values for  2″- 4″ thick, 2″- 4″ wide, Southern Pine #2 Dense and 2×4 Mixed Southern Pine #2 and all lower grades (i.e. #3, Stud, Construction, Standard, and Utility).   They have published an addendum to the NDS Design Values for Wood Construction that provides design values for these sizes and grades of Southern Pine and Mixed Southern Pine to use with the 2012 NDS, 2005 NDS, and the 2001 NDS.

The values for other sized lumber is still being tested.   Expectations are that the results will be published in September 2012.  In the interim, the Projected Design Values previously issued by the Southern Pine Inspection Bureau (SPIB) Board of Governors are available for use.  SPIB believes that these values will be the end-result of their testing.  SPIB states that these are not actual design values.

Stay tuned, more updates coming.