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The condition outside your home will have changed following a storm. Before going outside, start inside (next section) and view the outside from each room, checking for potential safety hazards. Pay particular attention to low hanging electrical wires and damaged or fallen trees. For the purpose of this post-storm check list, it is not necessary to use a ladder, or get on a roof, and that all viewing is to be done from a safe position on the ground.
Cracked Gypsum (Drywall)
Storm force winds will apply extreme forces on a house, and these forces increase exponentially with wind speed. For example, winds gusting to 160 km/h may apply 45 to 90 kilonewtons (10 000 to 20 000 lbs) of force to a typical two storey exterior wall. However, in practice, these forces will vary because wind is very dynamic and complex. Since every storm has unique wind characteristics, and direction, the damage done to a property in one storm will also differ from another. Cracks and other damage may be clues that resistance has decreased, or that future damage may be more severe (depending on wind speed and direction).
160 km/h windows may cause 10 - 20 000 lbs of force.
Inspect along the interior vertical corners of gypsum walls, concentrating on the exterior corners of the building, and along the joints between ceilings and exterior walls. If cracks are discovered, the structure of the property should be further evaluated to determine if the construction and condition of the building materials is acceptable.
Damaged Glazing or Storm Windows
Glass may be damaged by flying objects and storm windows may be exposed to enough winds to damage the frame mounting points. Check each storm window fastener attachment for gaps, distorted metal, and other forms of damage. Cracked glazing should be taped, and suitably covered, to prevent injury until repairs are completed.
Displaced Blown-in Insulation
Wind may blow into attics with enough force to move blown-in insulation. This is more likely to occur where porch overhangs have large areas of soffit vents and the underside of the roof (above the exterior wall) is high enough that rafter baffles (click here to see a typical example by Owens Corning) were not installed. It may also occur where baffles are missing from eaves, and may be an indication that your attic insulation is installed incorrectly. If so, have it inspected.
Identify Immediate Hazards
(If you skipped ahead, please go back and read the first section, Safety First.)
Low Hanging Electrical and Telecommunications Cables
Keep a safe distance and follow the advice of your local power utility (The following advice is provided by Newfoundland Power)
- Downed wires should always be considered energized or "live", and extremely dangerous.
- Do not approach or drive over a downed power line and do not touch anything it may be in contact with.
- If a downed power line falls on a vehicle, passengers should stay in the vehicle until help arrives.
- Parents are encouraged to talk to their children about the dangers associated with power lines.
Service conductors are supported from the utility pole to the house by a steel cable secured to the house with a bolt, or to an electrical mast above the roof. Storms may damage the mounting point or mast. Therefore, in addition to low hanging or downed wires, look at these mounting points for signs of deterioration, deformity, or similar damage. The service mast above the roof should be plumb. Masts, with conductor mounting points more than one meter above the roof, should be supported by a guy wire. This wire is installed at a 45° angle, downwards from the top of the mast, and connects to the roof in the opposing direction to the service conductor.
Although securing the tension wire to the fascia (outside vertical edge of the roof where gutters are attached) was once acceptable, it is a known failure point, and no longer permitted on new construction. Be especially careful to observe these types of connections. If your home has a service wire attached there, it is not a requirement to upgrade, however homeowners may decide to do so, depending on their circumstances.
Damaged or Fallen Trees
Trees may have already damaged your property, be in a weakened state where a fall is likely, or temporarily resting against other objects like electrical cables. Trees may be extremely heavy and are a serious hazard. If you discover a tree that is at risk of falling, stay clear of any area it may land, avoid adjacent electrical cables, and contact a qualified contractor to further asses the condition of the tree. (Here is a list of aborists and tree service companies in St. John's, NL.)
Fallen or Damaged Home Heating Oil and Propane Tanks
Oil tanks are commonly thought to fail due to corrosion and subsequent leakage, but tank legs and supporting base failures are also common failure modes. In a previous blog post, Fuel Burning Appliances and Insurability, the risks associated with this tanks was outlined, most importantly: 1 litre of home heating oil can contaminate 1 million litres of water; clean-up costs may be as high as $250 000, or even $500 000; and tank failures have increased more than 50% in a decade.
Check oil, and propane tanks, to verify they are upright and secured on their base. Visually inspect fuel lines for signs of physical damage or leaks. If leaks are discovered, report them immediately:
According to What I Need To Know About Domestic Oil Spills by the Government of Newfoundland and Labrador, the Government Service Centre in cooperation with the Canadian Coast Guard service, provides a 24-hour emergency response program for environmental emergencies. You can report a spill by calling 772-2083 or 800-563-2444.
Loose Building Materials and Debris
Bricks, Concrete, and Chimney Pot Materials On the Ground
The tops of masonry chimneys may begin to show signs of serious deterioration by dropping some cracked pieces of cement mix, bricks, or the ceramic pots. Any cracking in this area indicates a high risk of cracking throughout the chimney shell, especially at the portion extending above the roof line. If any debris is located, further inspection is necessary and repairs are likely. The upper portion of chimneys can crack off as a single piece, or crumble, falling to the ground, and should be considered a serious hazard, even if the chimney is not in use: don't let a decommissioned chimney go uninspected.
If you find pieces of asphalt shingles, compare them to the colour of your roof, and count as many as you can find. Sometimes shingles split at one or more of the three tabs, and other times the entire shingle may tear away. While both scenarios are important to address, whole shingles, and large quantities of broken tabs, indicate a more serious problem. Try to view the roof from ground level on all sides using binoculars, a telephoto camera lens, or from a neighbour's upper storey windows. While you're at it, inspect any fallen shingles for signs of deterioration such as granular loss, organic growth, blisters, or cracking. Photos, a count of damaged shingles, and general description, including the condition of the shingles picked up, will be very helpful when discussing the problem with a roofer. Unless absolutely necessary, replacing the entire roof should be delayed until sunny weather conditions allow solar activated shingle adhesive to bond. (Or risk doing this again!)
Loose or Missing Vinyl Soffit and Cladding, Fascia, and Eavestroughing
Probably the most common wind damage is to a home is blown off vinyl siding and trim. Vinyl products tend to be particularly vulnerable due to their design as well as poor installation habits. Vinyl expands and contracts with temperature in the amount of about 6 mm per 3 m length from -25° to 30°. Vinyl planks should be cut short to allow for some thermal movement, nails installed in the center of the horizontal nailing slots, and the nails should not be driven flush. Failure to allow for thermal movement creates buckling that loosens the bottom snap-in connection, and weakens the fastener attachment through the nailing fin. Nails should be corrosion resistant with a wide head and long enough to anchor a minimum of 20 mm (3/4") into the wood: this means into the studs. If vinyl cladding and soffit has detached from the building, it may be helpful to collect the loose pieces (if reasonably possible) because the colours may be difficult to match due to discontinued and normal weathering, as well as manufacturing tolerances.
Inspect all around the building, including the roof edge (fascia), underside of the eave (soffits), and exterior walls (fascia). Fascia and eavestroughing is often made from aluminum and has sharp edges; take caution and wear eye protection if these pieces are blowing in the wind.
Shifted or Not Level Decks and Exterior Stairs
Unfortunately wooden decks and stairs are often not built according to the standards of the National Building Code of Canada, and may also be significantly weathered due to age. These structures are at greater risk of wind damage than the house itself, and the damage may not be immediately evident. Look for signs of movement, including the gap between the deck and the house; nonlevel surfaces, non-parallel posts; creaking, groaning, and popping sounds when walked on; and noticeable bouncing.
In some areas, deck blocks (also known as castle blocks) are acceptable alternatives to footings for decks 600 mm, or even higher, above the ground. As you can see in the chart above, Wind Speed and Wind Load, wind forces increase dramatically with speed. In a 160 km/h gust, a 0.9 m^2 (10 sq. ft.) deck is subject to as much as 1100 newtons (248 lbs.) of force (not including stairs, guards, and rails) and this force includes uplift. Wind speeds can also be concentrated in localized areas such as around the corners of a building, or in narrow tunnels, further increasing this force. This is why otherwise well constructed, and brand new, decks blow away. (As you can tell, I'm not a fan of deck blocks.)
Sheds, Fences, Greenhouses
Survey other structures on the properties checking for movement, damage, broken glass, or other damage. Make sure fence gate latch securely where pets roam the yard.
What Calls to Make
Getting Professional Help
Home inspectors are experts with respect to identifying system components and reporting deficient conditions. More importantly, inspectors can explain the significance of defects and damage, and make recommendations for improvements, without bias associated with winning a construction project. Some inspectors are willing to do component inspections, such as inspecting a roof, separate from a whole house inspection. If you require inspection services, including component inspections, please see RJ Miller Building Professionals Home Inspection services for contact information, and details on our exceptional home inspection services.
If your property has suffered storm damage, you may be required to inform:
- your insurer (to record the damage); and
- your mortgage institution (to report the damage).
Recommendations on actions to be taken to report damage is outside the scope of this blog. Please consult with your legal expert to determine what course of action to take. (If you are a legal or insurance expert, and you have written on this topic, please feel free to add a comment and link to your article below.)
Did Your Questions Get Answered?
Your comments and questions are welcome, and they may be answered in the comments below, or added to this blog entry. Please feel encouraged to add them below. Thank you!