Webinar: Advanced Roofing Fraud Presenter: Rich Grimshaw, P.E., Forensic Engineer & Training Manager Webinar Questions & Answers

Transcription

1 Webinar: Advanced Roofing Fraud Presenter: Rich Grimshaw, P.E., Forensic Engineer & Training Manager Webinar Questions & Answers 1. What is the splatter size on fencing and metal surfaces versus the actual hail size? For hail less than 2 inches in diameter, the spatter marks are very close to the size of the hail that created it. That is, a ½-inch-diameter hailstone creates a ½-inch-diameter spatter mark. Hail larger than 2 inches in diameter often leaves spatter marks larger than the hail. 2. I see blisters most often on areas of highest water flow, such as under a downspout. Is this because of water entering the shingle after installation, and then vaporizing? I m not aware of any research or technical bulletins on this phenomenon, but I suspect that the flow of water across the blisters has an erosive effect, dislodging the granules at the edges of the blisters. In colder climates, freeze-thaw cycles may further facilitate the granule loss around the edges of the blisters. 3. With debris under a shingle that has resealed, is this not wind? The debris has to get under the shingle tab somehow, and wind is one way of depositing it there. But the presence of debris does not indicate that the shingle is damaged. The debris itself is not damage, and wind lifting the shingle tab and depositing the debris doesn t constitute damage, unless of course the shingle gets creased or torn in the process. 4. Are large deposits of granules indicative of hail? No, it is not. Neither does it indicate the shingles are damaged. Hail can facilitate minor granule loss, but the granule loss occurs because the asphalt has deteriorated from exposure to temperature swings and ultraviolet light. Once the granules lose adherence to the asphalt they can be moved from their at-rest position down the roof slopes by rain, wind, and gravity. 5. Do people ever use leaf blowers to simulate wind damage to a roof? Well, that certainly sounds creative, and I don t doubt that an artful fraudster could make it work. It might also be done inadvertently by a dutiful homeowner just trying to keep leaves and debris off his roof. But as far as I know, the practice is not widespread, and I don t know of any specific instances where this was discovered to have been done. 6. On page 27, you show circular damage with an undamaged center. In other roof systems I have seen the same damage but of disproportionate size to the collateral hail indicators. Could this be bird droppings? For example, hail identified as 1" but the hail signature shown on page 27 measured 3" diameter. I believe bird droppings can cause what you describe, though it is not common. I have also seen this pattern of granule loss caused by white latex caulk that painters inadvertently dropped on the roof. 7. Please clarify the cause of the zippering effect on shingle tabs. The zipper pattern is caused by installing the shingles using the vertical racking method. When installed this way, the first column of shingles is installed from the eave of the roof to the ridge of the roof. As the next adjacent column of shingles is installed, the outside tabs on the first column must be lifted to weave in the shingles of the second column. This lifting of the tabs can damage the seal strip, and if the shingle tabs are not lifted carefully, can cause curls, tears and other damage to the shingles. The curled and damaged corners on the tables leave a pattern of vertical zipper lines up the slopes of the roof. Additionally, the vertical installation creates an expansion joint at the ends of the shingles. Through normal heating and cooling, the shingles will expand and contract. This can cause the shingles to pull apart along these vertical lines. Vertical racking is not a preferred method of shingle installation. It is not recommended by the NRCA (National Roofing Contractors Association), and is it not recommended by many manufacturers for certain types of shingles. Nonetheless, it is a popular method of shingle installation with many roofing contractors especially on steep roofs.

2 8. If a small tornado has been verified in the area, could there be shingle damage on all four slopes? The presence of a tornado in the area is not by itself a reason to believe that winds were strong enough at a nearby property to cause damage to the shingles. A tornado is a rapidly rotating column of air. The winds rotate counterclockwise, which gives them a distinctive and predictable direction. This rotating column has a width that varies from storm to storm. For example, some tornados are 200 feet wide, and others are 2,000 feet wide. This width is the place where the winds are strong enough to cause destruction. Tornados also have a length ; they touch down, travel a bit, and then lift up. This length varies from several hundred feet to many miles. In order for a house roof to be damaged by a tornado, it has to be within the area defined by the tornado s width and length. And within this area, the wind speeds will vary. So one portion of the tornado may have winds up to 150 mph, while others parts have winds up to just 80 mph. If the center of the tornado passes right over the house, then shingles on slopes facing all four cardinal compass directions can get damaged. But if it passes right over the house, there s a good chance that lots of shingles are going to get damaged; maybe even the roof structure. If the center is not over the house, then the tornadic winds have direction, and you would not expect to see wind-damaged shingles on slopes facing all directions. Note that if our hypothetical house is not within the tornado s path as defined by its width and length, it will not experience the damaging tornado winds. Any damage to its roof is caused by thunderstorm winds or straight-line winds. 9. Can you talk about nail pulls vs. intentional damage? Nail pops are underlying backed out fasteners caused by expansion of the roof deck. We have found no correlation between nail pops and intentional damage. 10. Have you ever seen wind cause 'nail pull thru' on only one fastener (nail) on one edge of the shingle? No. 11. When there's no damage to the shingle but they are all pulled through the nail - which could easily be done by lifting up - how do you tell at that point if it's man made or wind lifted? It sounds like your question is more related to shingle sliding due to high nailed shingles. When nails are installed above the top edge of the underlying shingle, the underlying shingle is robbed of one-half of its intended fasteners. Gravity will cause the underlying shingle to slide downslope leaving the impression that they have pulled out. Loose shingles due to poor nailing practices are often marked by the lack of creased or torn shingles which is common when damage occurs from man-made practices. We see no way to compare the described pull-out with man-made damage. 12. How do nailing patterns affect the ability of the sealing strip to withstand thermal forces through seasonal changes? No issue only layout. 13. What material is used to reseal shingles that have lifted? Asbestos-free asphalt roof cement (ASTM D4586) is recommended. As reported by shingle manufacturer CertainTeed, examples of 10 acceptable sealants are: 1 DAP Blacktite, Sika Sikaflex 221, Gibson Homans Black Jack 2172, Karnak AR-Elastocalk (an asphalt-rubber elastomeric caulk), Karnak No. 81, Maaco Roof Repair RR-808, Monsey MBA Gold, Monsey MB Roof Cements, Rely-On Black Roof Cement, and Tapco 2100 Flashing and Adhesive. 1 CertainTeed Technical Information Sheet #119

3 14. If the roof is flaking, can hail exacerbate the problem? Can the identification of newly exposed mat be considered hail damage? The only flaking we have witnessed is on organic-mat shingles. The short answer is yes, hail can exacerbate the problem. However, we know that organic-mat shingles have a short lifespan and will deteriorate to the point of the shingles coming apart. We have to ask whether the hail has affected the functionality of the shingle, and if it has, the shingle would be hail damaged. 15. Will poor roof ventilation cause blisters? It can be one of the factors, one ingredient in the recipe. But by itself, poor ventilation is not sufficient. The asphalt mixture and manufacturing environment have to favor the formation of gas bubbles. The orientation of the roof slopes are also a factor, as different orientations experience different heat gain from radiation. For example, north-facing slopes are less prone to blistering. Local climate conditions are also a factor, with blister formation more prevalent in southern states than those of the far north. 16. How can hail damage be specifically identified in the donut shape if they vary in shape? It s true, hailstones vary in shape. It s also true that not all hail blemishes look like a donut. The classic hail blemish looks like a donut, and finding one or several of these on a roof indicates that other blemishes, with less classic appearance can be caused by hail. 17. Do you find that lifted shingles are the result of wear, tear, and maintenance as well as installation or manufacturing defects? Let me preface by saying I consider a lifted shingle to be one that is unsealed and is not lying flat. If the shingle has been moved from its original position, it is displaced. This would be the result of either wind or a manual means. Loose shingles are another topic. Loose shingles usually occur because the sealant strip has failed from normal aging, weathering, and installation. The seal strips have a very specific life span and will usually start to debond between 5 and 10 years, which we would consider age-related deterioration of the seal strip. If the shingles were installed using the vertical racking method, then the corners can become loose due to lifting the shingles during installation and this would be considered an installation defect. We have seen no evidence that supports lifted or loose shingles being the result of a manufacturing defect, so long as the seal strip was applied during the manufacturing process. 18. Is there a way to tell if a shake shingle is fire resistant or not? Laboratory testing. I don t know of any visual clues to use on site. 19. Earlier you mentioned bird damage. Is this damage from pecking/eating granules or scratching/roosting? The damage is caused by birds foraging for seeds and insects just under the edges of the shingles. They re not eating the granules, but they peck away at them and remove them to get to the food underneath. 20. What is the average cost of an inspection for possible hail/wind damage? Since travel time is one component of the cost, the average will vary widely with the project location. For example, the average cost in west Texas will be greater than that in Charleston, South Carolina. In urban areas, the cost for examining and providing a summary report on hail and wind damage to residential asphalt shingle roofs can be as little as $750. Costs increase with the size and pitch of the roof, travel distances, and the complexity of the reporting that is required. 21. Have you ever seen anyone throw baseballs to simulate hail falling? No. Sounds like a lot of work, and it might cause the neighbors to talk. 22. One of the slides that you showed was for wind damage to new construction in Wisconsin. The roof was installed in February. Couldn't it be a factor if the shingles were installed when it was too cold and additional adhesive wasn't used? Yes. It should be considered as a factor.

4 23. In what type of weather are shingles less likely to seal properly? Cold weather and cool weather with overcast skies. Shingles have to reach an ambient temperature of about 70 degrees in order to seal. On sunny days, the air temperature can be below 70 degrees because solar radiation will increase the shingle temperature. Shingles should not be installed when temperatures are below freezing (32 degrees). 24. Are there factors that you use to determine cosmetic vs. functional damage on metal or copper roofs? Cosmetic damage would be dents. Functional damage is holes or anything that ruins the finish that would cause premature failure. This doesn t apply to copper, but it can apply to other metals, like painted steel or galvanized metal. 25. Can hail cause damage to tile roofs? Yes, but the hail needs to be large. The threshold size is about 1 ¾ inches for concrete tiles and about 1 ½ inches for clay tiles. 26. Regarding maintenance, how would you make repairs without damaging the shingles from foot traffic? Foot traffic does the most damage when the shingles are really hot. So one strategy is to do the repairs during cooler times of day and cooler seasons. Another strategy is to use workers on the lighter end of the scale. If you can choose between Edgar who weighs 250 pounds and Nigel who weighs 150, go with Nigel. 27. How many hits per square are needed to indicate replacement of the entire slope? Timothy Marshall and Richard Herzog proposed a formula for determining when it is more economical to replace the shingles than to repair them. The formula is in their paper Protocol for Assessment of Hail-Damaged Roofing. (Let me know if you need a copy). The formula uses the cost of material and labor and adjusts for difficulty on steep slopes. So the answer for a particular roof really depends on local costs of material and labor. What s true for a roof in Macon, Georgia, won t be true for a roof in Tillamook, Oregon, or Paramus, New Jersey. 28. Can an architectural shingle crease while its tabs are intact? Or should the tabs be missing? Architectural shingles rarely crease. They are made of two laminations, and they generally are heavier (thicker) than three-tab shingles. Wind will lift them and blow them off the roof before it will crease them. The teeth on the top lamination are susceptible to creasing because they are prone to becoming unsealed before the end of the shingle s service life. 29. What kind of wind damage occurs from hurricanes? Hurricane winds vary from 74 mph to over 160 mph, so the damage from a hurricane will depend on the wind speeds at a particular location. It also depends on where the hurricane occurs. If it s Florida or Texas where the building codes require shingles that withstand hurricane winds and local jurisdictions enforce that, then a hurricane with the lowest wind speeds may not cause much damage at all. But, assuming the winds are strong enough to cause damage to roof shingles, the damage will be directional. A hurricane moving north out of the Gulf of Mexico will have the strongest winds on the eastern side of the eye. And those winds will be from south to north, so we would expect to see shingle damage on south-facing roof slopes. Keep in mind that airborne debris may also cause damage to the shingles (and other parts of the house). 30. How is cosmetic damage addressed in your inspections? We do not address cosmetic issues during our inspections. We address functional damage to asphalt shingles only.

5 31. We receive a lot of wind claims where there aren't any creases or missing shingles, rather excessive amounts of missing granules on the shingle; would this alone be an indication of wind damage? No it would not. Wind-damaged shingles are, by definition, those that are creased, torn, or missing. Granule loss is not a part of the definition. Granule loss is a normal part of the aging or weathering process. As the asphalt ages, the adherence between the granules and asphalt loosens, and ultimately the granule becomes unstuck. 32. Are there any tips for determining wind damage versus deterioration on old, "crunchy" organic shingles? If the level of deterioration allows for determining that the shingles have been creased, torn, lifted, or removed, then we can determine if the shingles are wind damaged or not. However, if the shingles are deteriorated beyond their useful life, then we must determine if the shingle s functionality has been affected; this will be a judgement call.