Tag | Wind Damage
Once a major storm hits, it’s too late to protect your home and property. But there are things you can do now to limit future wind damage. Some are fairly simple and inexpensive; others will require a contractor. You’ll need to consider the characteristics of your home, your financial resources and the building codes in your community.
This homeowner’s checklist will help you learn what you can do. For more information about the costs and benefits of each approach, talk to a professional builder, architect or contractor. You should also ask your building department about building permit requirements
- Is the roof sheathing properly installed?
During a windstorm, wind forces are carried from the roof down to the exterior walls, down to the foundation. Homes can be damaged when wind forces are not properly transferred to the ground. Roof sheathing (the boards or plywood nailed to the roof rafters or trusses) can fail during a major storm if not properly installed. Examine the sheathing from the attic. If many of the nails have missed the rafters, you may need to re-nail the sheathing. If you’re putting on a new roof, make sure the sheathing complies with current recommended practices. (more…)
This home owner had wind damage to the siding and fascia of the property. The siding had blown loose from one side of the garage due to the starter strip coming loose. We removed and reattached the starter and the loose siding. In addition, a length of fascia had been blown off the front of the house. We pulled off the remaining damaged & loose fascia and reinstalled new. This was all done outside of the insurance and we worked closely with the customer to keep within her budget.
In buildings hit by tornadoes, the threat to life is due to a combination of effects that occur at almost the same time. To understand the tornado damage that can occur in a building, the following must be considered:
- wind-induced forces
- changes in atmospheric pressure
- debris impact
Wind Effects on Buildings
The wind speeds generated by some tornadoes are so great that designing for these extreme winds is beyond the scope of building codes and engineering standards. Most buildings that have received some engineering attention, such as schools, and that are built in accordance with sound construction practices can usually withstand wind speeds specified by building codes. Meeting these code-specified wind speeds can provide sufficient resistance to tornadic winds if the building is located on the outer edge of the tornado vortex. In addition, if a portion of the building is built to a higher tornado design standard, then both building and occupant survival are improved. (more…)
Roof leaks are a nuisance for many homeowners. They can be difficult to diagnose – that is a fact. To make matters worse, different weather conditions will produce leaks in different locations.
The vast majority of roof coverings operate using the principal of gravity. This can be a big help in locating a leak source. However, horizontal roof boards can trick you. A leak may actually be eight to 10 feet sideways from where you see the wet ceiling or spot in the attic.
Finding the source of some leaks is easy. Others will require detective work and possibly a garden hose and an inside spotter. If you don’t feel comfortable on a roof, you will have to find an honest roofer to assist you. Sometimes this can be as hard as finding the smallest leak! Here are some tips that may help you find a pesky roof leak:
The Field of Shingles
If your roof is older, it is possible that the leak is within the roof field. This means the expanse of shingles, slate, shakes, whatever. If your roof is asphalt, then you can walk around with ease. Other materials such as slate, concrete tile or clay tile may not be so forgiving. You can crack roofing if you walk on it, so be careful. With regular shingles, look at the tops of the vertical knockouts. Look for missing colored granules. Look for cracks. Possibly a nail has backed itself out of the roof sheathing. Simply take your time and hunt.
A valley is a line where two roof planes intersect. Here in Cincinnati we use a metal flashing in the valleys. Some areas use rolled roofing. Other places simply lace the shingles together. Valleys can be big problems if you do not trim the shingles correctly. When you trim a shingle for a valley you end up with a chisel point on the end of the shingle. If a second cut is not made to make this point like an arrow point, then water can travel along the top of the shingle and find its way inside your house. The shingle wrapper tells you how to make this simple second cut.
Head Wall Flashings
Some roofs stop at a vertical wall. A metal flashing must be in place to direct water streaming down the wall away from the stopping point of the shingles. This flashing may be behind wood siding or in front of a brick wall. The flashing should extend over the shingles at least three inches. If the wall is brick or other masonry, the flashing must bend and extend one inch into a mortar joint. Tar, caulk or roofing cement should never be used in conjunction with these materials. If you see them, it is a sign that someone tried to patch a leak!
Wall Step Flashing
Some roof leaks happen at step flashings. You find these flashings where a roof climbs alongside a vertical wall. As each row of shingles is laid, a step flashing is installed over the shingle next to the wall. Part of the flashing turns up on the wall and the other portion gets covered by the next row of shingles. Look for rust or holes in these flashings. In reality, if all is well, you will be able to see only the smallest portion of these flashings.
These devils are the source of many a leak. Chimneys contain four different types of flashing. All must be right or you will have a leak. Plus, the counterflashing that goes into the brick mortar joint must be right. A hairline crack above the flashing can allow vast amounts of water to run behind the flashings. Look for soldered corners of flashing that might have broken or have holes. Do not use caulk to repair these flashings!
Plumbing Vent Flashings
Newer vent flashings are a concern of mine. Many of these incorporate a rubber seal with an aluminum flashing. The rubber can fail in as little as 10 to 15 years. Look for cracked rubber around the plumbing pipe. The flashing should dive up and under the shingles that extend up roof from the middle of the plumbing vent. The bottom half of the flashing should be exposed and actually cover the shingles.
Furnace or B-Vent Flashing
These flashings are basically identical to plumbing vent flashings. However, they sometimes have a metal storm collar. These simply fit tightly around the vertical pipe that exits the roof. If they become loose, the storm collars can cause leaks.
Ice Dam Leaks
Ice dam leaks plague people in the snow belt. These leaks can happen even if everything on your roof is just fine! Ice dams block the natural flow of water down a roof. The water begins to back up under flashings, shingles, tar paper, etc. Once water begins to flow into the house, it can drip for days. The only means of prevention is to install membranes under the roofing. The membranes won’t stop the ice but will stop water leaks if installed properly.
Wind Blown Rain Leaks
Wind driven rain can also be a major problem. Once again, you could actually have a good roof and wind will drive water up and under your roofing materials. The only lines of defense are tar paper and the ice dam membranes.
If you have metal valleys, you may want to hem the edges. This means that the hidden edges of the valley actual have a 180 degree bend. This creates a channel that directs wind blown rain back to the bottom of the valley.
Roofing cement under shingles on the edges of roofs that face the wind are also a good idea. Don’t underestimate the power of a 70 mph sustained wind-driven rain.
Sometimes you think you have a roof leak when in fact the roof is fine. Attic condensation is a prime example. High humidity can cause condensation and “rain” to fall in your attic. It can also make the underside of the roof sheathing look wet. You think you have a leak instead.
Chimney crowns can develop cracks. The inside surface of the chimney gets discolored or the plaster bubbles. You think a roof leak is the cause.
Siding can be missing above a roof. This can cause water to enter behind head flashings. Be a good gumshoe and snoop around for the leaks!
About the article:
Carter, Tim. “Roof Leak – Ten Most Common Leak Locations.” AskTheBuilder n. pag. Web. 16 Jun 2010. <http://www.askthebuilder.com/B188_Roof_Leaks_-_Ten_Most_Common_Leak_Locations.shtml>.
Addtional Recommended Reading:
Every year in Colorado, we expect late snow storms, early rains, sporadic tornados and violent hail storms. Any of these natural occurrences can be detrimental to a property depending on the proximity and the intensity. This featured project that we present to you is a roof that was damaged due to a hail storm. With the roof replacement, NuBilt replaced T-Lock shingles with 30 Year Dimensional Shingles.
Sometimes, a tree falls in a forest and someone does hear it. Or, it falls onto your neighbor’s property and damages something. When that happens, their homeowners insurance company will be the one to hear about it.
Dr. Robert Hartwig, President of the Insurance Information Institute (III) knows first-hand how homeowners insurance can become involved when one of your trees falls on a neighbor’s property.
Whose Insurance Pays?
If one of your trees falls and damages a neighbor’s property, “generally speaking, it is your neighbor’s insurance policy that is called upon to pay the damage,” points out Hartwig. “Since his insurance is being impacted,” Hartwig continued, “you probably won’t face an insurance premium increase as a result.”
However, “your neighbor could come after you to cover his deductible. Matter of fact, when one of my trees fell on my neighbor’s fence, it destroyed some of his fence and damaged fruit trees. In the interest of neighborly relations, I voluntarily paid for a new pear tree, so between what the insurer paid and what I paid, he didn’t have any out-of-pocket expense,” says Hartwig.
The upshot? “My neighbor and I are still on speaking terms, which is a good thing. I paid for the new fruit tree, because I thought it was the right thing to do, although I was not obligated to do that.” Hartwig’s story underlines the fact that, in general, your neighbor’s insurance covers your neighbor’s property. However, although you and your insurance company may not legally have to make a payment, it’s usually best to maintain good relations with those around you.
The major exception to the rule of thumb that your neighbor’s insurance will pay is the case of negligence on your part. If your tree was dead or diseased, and a judgment or settlement finds that you knew or should have known about that, you could be legally liable for the damages. This is especially true if your neighbor has documentation proving that he or she complained to you or the city about the state of your tree.
Section two of most homeowners insurance policies covers liability, including the cost to defend you in a lawsuit. Your neighbor could submit a claim to your insurance company if they believe you are at fault. If your neighbor sues you, claiming that you were negligent in failing to take care of your tree, your insurance company will pay to defend your case, and will pay for damages if you’re responsible. The cost of legal defense is in addition to policy liability limits, although the amount of damage paid for is subject to these limits.
Prevention is the Best Cure
To avoid this situation, have your trees trimmed and inspected periodically to make sure they’re not dead or falling down. If you’re worried about trees on your property falling during a storm, have them trimmed or removed. If you are concerned about a neighbor’s tree, write a polite letter to your neighbor and the city, but realize that it may cause a disagreement.
Other Homeowners Insurance Options
Another option under your own homeowners insurance policy is the Damage to Property of Others coverage in the Other Coverages portion of the liability section. This coverage does not have a deductible and it can be used without a judgment or admission of legal liability, which can help speed up the payment process. The amount of coverage for Damage to Property of Others, typically $1,000, is in addition to the policy’s liability limits. However, remember that using your own insurance constitutes a claim against it and a possible premium increase. Therefore, only use this type of coverage if you can’t afford to pay for the damage yourself.
If your tree falls on your neighbor’s porch, your neighbor’s homeowners insurance will usually pay for the damage. However, remember that each area has different laws, and each policy has exclusions explaining what is not covered.
Do you have any questions or comments? Please let Insurance.com know.
About the Author:
Insurance.com was founded in June of 2000, as ComparisonMarket, Inc. With support from some of the top insurance providers in the country, such as The Hartford, Liberty Mutual, Progressive and Travelers, Insurance.com was quoting in 45 states by November of 2001. ComparisonMarket, Inc. acquired the Insurance.com Agency and domain name in July of 2003, and quickly put the strong brand name to work. By July of 2004 Insurance.com had sold over 100,000 policies and by July of 2009, Insurance.com had sold over 800,000 auto insurance policies.
View original article here.
Tornadoes are nature’s most violent storms. Spawned from powerful thunderstorms, tornadoes can cause fatalities and devastate a neighborhood in seconds. A tornado appears as a rotating, funnel-shaped cloud that extends from a thunderstorm to the ground with whirling winds that can reach 300 miles per hour. Damage paths can be in excess of one mile wide and 50 miles long. Every state is at some risk from this hazard.
Some tornadoes are clearly visible, while rain or nearby low-hanging clouds obscure others. Occasionally, tornadoes develop so rapidly that little, if any, advance warning is possible.
Before a tornado hits, the wind may die down and the air may become very still. A cloud of debris can mark the location of a tornado even if a funnel is not visible. Tornadoes generally occur near the trailing edge of a thunderstorm. It is not uncommon to see clear, sunlit skies behind a tornado.
The following are facts about tornadoes:
- They may strike quickly, with little or no warning.
- They may appear nearly transparent until dust and debris are picked up or a cloud forms in the funnel.
- The average tornado moves Southwest to Northeast, but tornadoes have been known to move in any direction.
- The average forward speed of a tornado is 30 MPH, but may vary from stationary to 70 MPH.
- Tornadoes can accompany tropical storms and hurricanes as they move onto land.
- Waterspouts are tornadoes that form over water.
- Tornadoes are most frequently reported east of the Rocky Mountains during spring and summer months.
- Peak tornado season in the southern states is March through May; in the northern states, it is late spring through early summer.
- Tornadoes are most likely to occur between 3 p.m. and 9 p.m., but can occur at any time.
How can I protect myself from a tornado?
Also, check out:
- Video: Windsor Tornado Relief Work (2008)
- The American Red Cross Preparedness Publications/Safety Tips.
About the Author:
Federal Emergency Management Agency (FEMA). The primary mission of the FEMA is to reduce the loss of life and property and protect the Nation from all hazards, including natural disasters, acts of terrorism, and other man-made disasters, by leading and supporting the Nation in a risk-based, comprehensive emergency management system of preparedness, protection, response, recovery, and mitigation.
A building envelope is a term used to define the components of a building that separate the interior environment of a house from the exterior environment. People often think of the building envelope as being the walls and roof of a structure. Although a building envelope can include these components, the building envelope is not necessarily defined by these components. For example, the interior wall between a house and an attached garage is typically insulated and is considered to be a component of the building envelope. The exterior walls of the attached garage in this example are not considered part of the building envelope because they do not separate the interior environment from the exterior environment.
A roof is considered part of the building envelope when there is no attic, such as a roof over a cathedral ceiling where the drywall is attached to the underside of the rafters. When there is an attic between the roof and an insulated ceiling, the insulated ceiling separates the interior environment from the exterior environment and is considered a component of the building envelope. Typical components of the building envelope include a building wrap, exterior sheathing, insulation, and a vapor barrier.
The building envelope plays a vital role in the energy efficiency of a building. One of the keys to an energy-efficient house is minimizing openings such as cracks and gaps in the building envelope. Any openings in the building envelope allow inside air to escape to the outside. The conditioned flow of air out of the house will be balanced by unconditioned air intruding into the house. During the winter, the intruding air needs to be heated.
The building envelope also helps to stabilize humidity inside a house, preventing undesirable changes in moisture that can cause damage. When intruding air enters the house at 32 degrees with 50 percent relative humidity, the relative humidity will decrease to 12.5 percent when the air is heated to 70 degrees.
This dry air will cause the wood framing and the components of the house to dry out and shrink, especially across the grain. When wood trim, wood doors, and wood flooring dry out, they shrink to expose paint or stain lines. Wood flooring can dry out and squeak during the cold winter months. Low humidity can also cause cracks and gaps to appear in wood flooring.
Framing can shrink enough to cause cracking in drywall. Cracks in drywall above wood headers (lintels) are the most common cracks in a house. When this wood framing assembly shrinks from drying out, it can crack the drywall at the top corners of the door frame, especially at the taped joints.
A well-built building envelope will maintain a fairly constant temperature throughout the house. When proper attention is not given to the building envelope, problems such as cold spots and frozen pipes can result.
Construction of a “knee wall” or “eyebrow roof” is one area where special attention must be given to the building envelope. Figures 1 and 2 provide details on preventing air intrusion through the building envelope at knee walls and eyebrow roofs when constructed on the second-floor level of a two-story house. Blocking is installed between the floor joists to prevent air intrusion at the floor joists below knee walls. Sheathing is installed continuously behind the eyebrow roof to prevent air intrusion through the exterior wall.
Sometimes fiberglass batts are used to close this space without sheathing or blocking. Batts of insulation will not seal the area and can be displaced by the wind. Even worse, loose blown cellulose, when used at this detail, will be eroded by wind.
Freezing of interior pipes can occur when the knee wall or eyebrow roof is symmetrical on both sides of the house and when the building envelope is not properly constructed in these areas. Wind can enter through the improperly constructed building envelope on one side of the house; pass through the house along the cavities created by the floor joists, second-story floor sheathing, and the first-story drywall ceiling; and exit through the improperly constructed building envelope on the other side of the house. If waterlines run through any of these cavities, the house is only one cold, windy day away from having a frozen pipe burst.
If there are open areas in your building envelope, the best way to seal the envelope is to use blocking for closure and to apply spray foam insulation. The spray foam provides an insulation factor as well as seals the cavity to prevent air intrusion.
The referenced details are from the Journal of Light Construction Field Guide, A Manual of Best Practice, Volume 2 To learn more about Donan Engineering and the services we provide, please visit our website at www.donan.com.
Donan Engineering Disclaimer
The information contained herein is intended for informational purposes and cannot be relied upon in all situations, as each forensic investigation is unique in scope and circumstances. All information contained is written in connection with the promotion or marketing of the specific matters addressed. Anyone addressing specific instances of any forensic matters should consult an independent professional to review the particular circumstances of their unique situation.
About the Author:
Donan Engineering Co., Inc., a family-owned company founded in 1947, provides full-service forensic engineering and fire investigation services. For over 60 years, Donan Engineering has been providing unbiased answers to our client’s complicated questions.
This article was reproduced with permission from Kevin Abell of Donan Engineering Co., Inc.
Hail forms when frozen water drops are lifted in turbulent wind regimes during thunderstorms. The frozen drops of water increase in size and eventually fall to earth as hail having been driven by a combination of gravity and wind forces. Hail stones vary in size from pea size (1/4 inch diameter, little roof damage), through marble size (3/4 inch in diameter, threshold damage to roof materials) to golf ball size (11/2 inch in diameter, typically severe damage to roofing materials).
Hail size distributions tend to be localized with some roofs damaged, while others are not. Wind direction plays an important role, as well as roof pitch. A direct impact of hail on a shingle is more damaging than that of a glancing blow. Figure 1a illustrates the dynamics of hail impact on two different roof pitches.
The home on the left would sustain more roof damage than that on the right, because of the more direct impact on the left as opposed to the less damaging, glancing, blow to the right. Wind conditions can distort damage to a home as illustrated in Figure 1b.
The home on the left has more glancing blows to the roof from the wind, while the windward wall comes under attack from direct hail impact. The right wall is protected and undamaged from the hail. The home on the right will more likely sustain roof damage on the windward side because of the more direct impact. Assessing hail damage is often accomplished by a roof inspection, which usually occurs several days to several months after the hail event. Determination of whether hail actually fell at a site can be made through statements and weather reports. Inspection of thin, aluminum fixtures helps verify hail impact.
Figure 2a shows denting on a roof vent cap indicating that hail had struck the vent at one time.
Figure 2b shows denting on a flue vent indicative of hail impact at one time. The denting on these two fixtures does not impede their function.
Figure 2c shows deformation to condensing unit fins on an air conditioning system, as a result of a driving hailstorm. This damage does impair operation of the unit, in that air flow through the coils is reduced, causing higher refrigerant temperature, lost performance and lost reliability.
Figure 3 shows shredded and pock-marked paint from a driving hailstorm. The base wood was undamaged but repainting was required.
Figure 4 shows mild impact marks on a cedar shingle, consistent with hail impact. These marks will typically dissipate over time with virtually no effect on shingle life.
Figure 5 shows more severe shredding from hail impact. If the impact marks are causing severe splits, then shingle life will most likely be adversely affected.
Figure 6 shows impact damage to siding as a result of wind driven hail. Some shredding and minor splitting has occurred but the siding appears structurally sound.
Hail damage to asphalt shingles includes severe granule loss, material removal at the edges of the shingles and penetration. Figure 7 shows grit loss from asphalt after pounding from a hailstorm.
New asphalt shingles are more resistant to hail impact than older shingles since the asphalt becomes more brittle with age. Warmer shingles are more compliant and more resistant to fracture from hail when compared with colder shingles. Shingles rely on a structurally sound substrate for hail damage resistance. Flexible roof sheathing allows the shingles to flex during impact causing damage, while more rigid roof sheathing supports the shingle during impact resulting in less shingle damage.
In recent years, roof shingle manufacturers have been listing products that conform to Underwriters Laboratories test standard UL 2218, which classifies the resistance of a particular product to hail damage. The test entails dropping steel balls on samples and observing the damage. A Class 4 rating is the most resistive to hail damage, while the Class 1 rating is the least resistive. Some insurance companies are reducing premiums when Class 4 shingles are used. The roofing industry takes issue with some of the testing methods, indicating that shingle aging and thermal environments are not taken into account.
Most hail related damage is cosmetic and does not affect the useful life of roof shingles. In other cases severe wood splitting, significant granule loss, penetration of the shingle and fracture may require shingle replacement.