Shingle Damage Evaluation

Transcription

1 Shingle Damage Evaluation Introduction There have been a number of hail producing storms that have passed through Northeast Ohio since 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 and previous storms. We observed and documented hail damage to exterior building components and damage caused by other mechanisms. We observed flaking, cracking, clawing, wear, etc. on numerous older roofs that had 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; loosening of granules from lichen growth; loosening of granules from bird droppings; etc. So how does one evaluate a roof for hail damage? In a word, experience. There are industry guidelines and laboratory studies that provide a criteria for assessment of alleged hail damage; but often times there is also a twist to the claim, just like an Alfred Hitchcock movie for those who can remember Mr. Hitchcock (and if you haven t seen one, go to Blockbuster and rent a few, one of my favorites is Dial M for Murder). So, let s review some basics for the evaluation of hail damage to asphalt shingles.

2 Construction of Asphalt Shingles Asphalt shingles are commonly comprised of a mat covered with asphalt and granules. The mat is the base of the shingle. It is coated with asphalt and sprinkled with granules that adhere to the asphalt. The mat of an organic shingle is a cellulose fiber made from wood, recycled rags, and/or recycled paper. The organic mat is similar to the black roofing paper that can be found on a three foot tall roll in the roofing aisle at Home Depot. The granules on an organic mat are bonded with a second layer of asphalt coating. Shingles with an organic shingle mat were more common prior to Since about 1980 fiberglass shingles have become more popular. 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. Thus, a fiberglass mat shingle is much thinner than an organic mat shingle. 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 the figures on this page. This construction gives a more three dimensional appearance to the shingle. A three dimensional appearance may also be produced 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 portions of the shingle. Laminate shingle construction shown in sketch and in photograph. 2 P age

3 Appliqué shingle exhibits cracking in the area of the appliqué. Aging of Asphalt Shingles Asphalt shingles age and weather from exposure to water and sunlight. The intense sunlight deteriorates the asphalt which bonds the granules to the fiberglass mat. Rain water washes away the loose granules, which exposes more asphalt to the sunlight and accelerates the deterioration. Deterioration of the shingles may cause them to lose their ability to shed water to the gutters and leakage may begin. The normal service life of shingles in Northeast Ohio is approximately twenty years. Shingles that are nearing the end of their service life or have exceeded their service life often exhibit clawing, embrittlement, breakage, curling, cracking, or widespread granule loss. These conditions are often not only a result of normal aging, but their progression may be accelerated by other factors. Shingles on the south and west slopes usually age faster than shingles on the north and east slopes. The accelerated aging is due to the more direct exposure to sunlight. Shingles which are shaded from the sun and/or which are shielded from a breeze by trees may also age faster due to the inability to dry quickly after exposure to rain or snow. In the summer, shingles over a poorly ventilated attic or rafter spaces are exposed to excessive heat, similar to a double broiler, and in the winter are exposed to excessive airborne moisture that migrates from the living area through the attics and rafter spaces and into the shingles. The seasonal pattern of excessive wetting and excessive heating accelerates the aging process of the shingles. A common pattern of damage due to aging in appliqué shingles is premature cracking and granule loss on the surface of the appliqué. The greater thickness of asphalt on a portion of the appliqué shingle is prone to exhibit cracking from differential shrinkage. That is, as the top coating of asphalt dries out and shrinks more than the lower coating, the top coating is stretched by the lower coating, resulting in shrinkage cracking. See photographs on page 5. 3 P age

4 The following photographs show some examples of aging damage: Clawing at the corners of the shingles. Clawing at the corners of the shingles. Widespread granule loss and breakage. Widespread granule loss and breakage. 4 P age Widespread, relatively uniform granule loss is often found on poor quality shingles.

5 Curling at the corners of the shingles. Curling at the corners of the shingles. Cracking. Appliqué peeling from shingle. Appliqué exhibits cracking. Remainder of shingle exhibits no damage. 5 P age

6 Hail Damage to Asphalt Shingles Industry standards and studies 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, and 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 in the mat. Industry studies have shown that softness in the mat, commonly called a bruise, is indicative of a fracture on the bottom side of the shingle or in the mat. Hail damage can be detected immediately after the hail impact either by visual observation and/or by tactile examination of the shingles. Hail damage does not appear later. Granule loss alone, such as evidenced by granules in the gutter or widespread and relatively uniform loss of granules on the shingles, does not prove that a shingle has been functionally damaged by hail. That is, granule loss from hail impacts which does not fracture the mat does not affect the long term service life of the shingle. Furthermore, widespread and relatively uniform granule loss is not considered hail damage but is considered normal wear and tear. Granules are commonly dislodged when the shingles are exposed to heavy rainfall, wind, small hail impacts, and normal foot traffic. Hail damage. Hail damage. 6 P age

7 Hail damage on ridge cap. Hail damage. Hail damage. Hail damage. Industry studies indicate that composite asphalt shingles can usually withstand hail up to ¾ inch diameter without functional or cosmetic damage. The size of damage producing hail may vary some due to the condition or age of the shingles, the quality of the shingles, the hardness of the hail (such as, slushy ice versus solid ice), and the speed and direction of the wind driving the hail. The size, direction, and damage producing effect of the hail can often be determined from an examination of other exterior building components. Evidence of building exposure to hail are splash marks and/or indentations in roof vents, flashings, air conditioning fins, gutters, downspouts, siding, window sills, screens, wood decks, etc. The size of the splash marks and the indentations give an indication of the size, direction and damage producing effect of the hail. Splash marks are areas where the discoloration from normal oxidation or dirt has been rubbed off the surface by the hail in a somewhat circular, usually tear drop shape. Splash marks do not 7 P age

8 cause any functional damage, but may require the surface to be cleaned of the remaining discoloration so that the surface appears uniform again. If thin gage metals, such as, vents, trim, gutters, downspouts, flashings, etc., are not dented, it is probable that the shingles were not exposed to a size of hail that could cause damage. However, indentations in these alone are not an indication that the shingles have been damaged by hail impacts. Furthermore, sometimes these do not show damage because they were fabricated with a relatively thick gage material. In wood surfaces, splash marks will eventually discolor or may be removed by cleaning the surface. Light indentations in wood surfaces will become less visible as the wood material seasonally shrinks and swells. Splash marks on shutter (dark blotches, not the white bird dropping). Splash marks on window trim covering. Splash marks and indentations in wood sill. 8 P age

9 Newer shingles withstand hail impact better than older shingles because the material is more flexible and forgiving. Shingles applied directly over the roof deck withstand hail better than those over a previous layer of shingles because a hard roof deck provides more support than the softer layer of shingles below. The cap shingles at the ridge and hips also are more susceptible to hail damage due to the lack of direct support. Other Surface Damage to Asphalt Shingles It has been our experience that some damages are mistakenly perceived as evidence of hail damage. For example, in organic shingles flaking is the separation of the granules and the second coat of asphalt adhesive from the base coat. When the flaking is relatively round, it appears to be hail damage. However, closer examination discloses that the round flakes are generally along a ridge in the shingles or do not exhibit an indentation, a fracture in the mat, or a soft spot. Flaking. Flaking. Flaking. Flaking. 9 P age

10 Shingles often exhibit a somewhat circular shaped area of granule loss and/or a tear in the mat over the roofing nails. The granule loss and the tear are due to the shingle being raised by the nail. The raised condition of the nail is due to the nail not being fully driven, the nail being driven in at an angle, or the backing out of the nail. The backing out of the nail is due to the seasonal shrinking and swelling of the roof deck. These are distinguished from hail damage by their relatively uniform pattern of location and/or the raised condition of the nail head. Shingle exhibits granule loss over raised nail head. Shingle exhibits granule loss over raised nail head. 10 P age

11 Since lichen damage to shingles often appears as circular shaped areas of granule loss, it is often mistaken for hail damage. Lichens, which are algae growth, consume the asphalt and loosen the granules. When the lichens become dormant, the granules wash away leaving a round area of exposed asphalt or mat. The lichens often leave remnants on the shingle surface, unless the shingles have been power washed. (We do not recommend power washing shingles as it may accelerate aging.) Damage from lichen growth does not exhibit a fracture, indentation, or soft spot. Lichens. Lichens. Lichens. Lichens. 11 P age

12 Sometimes relatively circular shapes of granule loss from bird droppings are mistaken for hail damage. Damage from bird droppings are usually found under antennas, trees, or similar raised perch. Damage from bird droppings are due to deterioration of the asphalt coating from the bird droppings. Damage from bird droppings do not exhibit a fracture, indentation, or soft spot. Damage from bird droppings. Damage from bird droppings. Sometimes manufacturing defects are mistaken for hail damage. For example, the delamination and deterioration caused by the overlapping of the mat material during manufacturing or the poor bonding of the asphalt coating to the mat during the manufacturing process. Manufacturing defect overlap at splice during fabrication causes delamination. Spot defect. 12 P age

13 Broken blisters expose a round area of shingle mat and are often misdiagnosed as hail impact damage. A blister occurs in a shingle when sunlight heats the volatiles trapped within the asphalt coating, such as, kerosene or water. The heated volatiles vaporize and expand. The heat softened asphalt bubbles and forms a blister. When the bulged surface is knocked off by normal wear, foot traffic, or hail, an exposed round area appears. Blisters are usually relatively small about the size of a pencil eraser. The size and the lack of an indentation, fracturing, or soft condition in the mat indicates that it was not caused by a hail impact. Blistering. Ruptured blistering. Corner breakage is usually due to lifting of a corner with one s finger or a dog ear bending at the corner when a bundle of shingles were dropped on the corner. Corner breakage damage. Multiple corners broken from bundle drop. 13 P age

14 We have observed damage that exhibits evidence of being mechanically applied as by a hammer, screwdriver, or other hard object. These are usually uniform in size and exhibit a patterned spacing. On many of these we have been able to render a professional opinion regarding the cause of the damage. Most of the time this type of damage is inadvertently applied during normal access to the roof. However, sometimes the pattern of the damage, such as, location, spacing, frequency, concentration, similarity, uniformity, etc. indicate that the damage was intentionally applied. Gouge in shingle from hard object. Scuff of shingle. Double hit indicates mechanically made damage. Deep, near perfectly round indentations are from a hard tool. 14 P age

15 Intentional shingle damage. Note impression in asphalt Intentional shingle damage. Note impression in asphalt. Intentional shingle damage. Note granules pulverized by hard tool. Intentional shingle damage. Note granules pulverized by hard tool. Marks in shingle exhibit a recurring pattern. 15 P a g e Marks exhibit tool impression.

16 Lastly, in some cases, the shingles are in such poor condition that any size hail results in the dislodging of already loosened granules. Is this hail damage? In these cases, we can only describe what has occurred and the coverage for these depends on the policy language which others are required to interpret. Previously loosened granules dislodged. Previously loosened granules dislodged. Previously loosened granules dislodged. In closing, we hope these observations assist you with evaluation of your situations. However, we are sure that other types and patterns of shingle damage will arise. These other conditions may be evaluated in a similar manner. If you have a question about damage to shingles, please contact us. We would be pleased to answer your questions. Article written in January 2009 for the Prugar Consulting, Inc. Website Newsletter Prugar Consulting, Inc., All rights reserved. 16 P age