| China is one of the countries that suffers great loss from typhoons. Every year, large areas of coastal provinces were frequently hit by typhoons and we have recorded loss from our clients, including serious property damages, injury to people and even deaths due to various reasons. Our Claims and Risk Management team in China has been working relentlessly to advise clients by sharing our knowledge about typhoon, its hazard, prevention and risk aversion methods. The team also helps our clients by introducing related insurance claims and risk management solutions. We hope this article can let our readers gain more insights on loss prevention for their properties. |  Effect of typhoon on building structures |
Protective measures for building structures
In recent years, people have seen the severe damage to buildings made by tyhoons. The majority of the buildings today can withstand strong winds that their load-bearing pillars and main beams will remain intact after tropical storms. However, their building envelopes, such as the roof, doors and windows, exterior walls and purlines were subject to serious damages.
The most serious problem is that once the roof is damaged, its interior and the assets within will be subject to rain or wind damages. In fact, about 80% of the damages made by strong winds are roof system damages according to an incomplete statistics. From 1998 to this date, there were around 1128 cases of strong wind damage to roof with an accumulated loss of USD 1.7 billion.
The major causes of damage from strong winds to a building are the windbag and Venturi effects induced during the event. When wind blows through the building structure, there will be a difference between the air pressure on both sides of the walls. This build-up will eventually cause the roof to be blown away. The wind pressure is not equally distributed on the roofings. Usually around four edges and the corners of the roof will suffer more wind pressure than the centre (the wind pressure of corner area is 2.5 times greater than the centre). The best measure is to consider different wind pressure right at the designing stage of the roof and lower the risk at its source.
Usually, metal roofings are more vulnerable to strong wind damage. The reasons are:
- The wind-resistant pullout capacity of metallic roofing itself is not adequate.
- The wind-resistant pullout capacity of metallic roofing’s fasteners is not adequate.
- The sealant and self-tapping screws on the roof panels are missing.
- The flashing of the roofing system is loosely installed.
- In the event of strong wind, the structures on building envelopes (windows, doors, openings, etc.) were not closed on time.
The facilities installed on the rooftop are not appropriately fixed in place.
By studying past analyses of damages to buildings in China, we notice that reinforced concrete structures with SBS (styrene-butadiene-styrene) roofings have better windproof performance. Metallic roofings are usually prone to damage under the effect of strong winds. The main reasons are:
- The wind-resistant pullout capacity of metallic roofing is not adequate.
- The wind-resistant pullout capacity of metallic roofing’s fasteners is not adequate.
- The sealant and self-tapping screws on the roof panels are missing.
For existing buildings, how can we reduce risks reasonably and effectively before the arrival of strong winds? We suggest carrying out inspection and maintenance on your buildings prior to the season of strong winds with a focus on the following areas:
| 1 | Are the roof flashings firmly installed? This can be confirmed easily with on-site inspection by pulling with hands. |  |
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| 2 | Are there any damaged or missing screws on the roofings? On-site inspection of the roofs for damaged or missing screws should be carried out. If there is a loss of consecutive retaining screws in some areas which leave holes in the fasteners, please pay attention to the fact that your buildings’ roofings could have lost the ability to withstand strong winds. |  |
| 3 | Are the structures on building envelopes (windows, doors, openings, etc.) closed or sealed promptly before the incoming of strong wind? The closed area should be sealed on time to prevent strong winds from entering the interior of the building, increasing pressure partially and causing damage. |  |
| 4 | Are the roofings in good condition? Metallic roofs can rust. Is the SBS waterproof layer firmly installed? Are there any rust found on the roof flashings and are they firmly installed? If the roofings were in bad condition, please pay attention to the fact that your buildings’ roofings could have lost the ability to withstand strong winds. |  |
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Besides daily maintenance, business owners can hire qualified risk engineers and consultants to help. Leveraging their industrial expertise and knowledge, they can perform thorough inspections on your buildings and disaster prevention systems while providing the best advice to mitigate risks.
Typhoon hazard prevention and risk management
China is one of the countries affected most severely by typhoons globally. These climate events are characterized by the huge size of the affected area, high frequency, and the heavy loss and damage they caused. For various reasons, our clients suffer from losses due to typhoon events every year which have caused substantial property damage and injuries or deaths of their personnels.
Facing the risks of typhoon damage, purchasing insurance policies with adequate coverage and carrying out comprehensive inspections on building structures are obvious choices for all businesses.
For property insurance products, Motor, Agricultural, Fire and other Catastrophe (including Property and Home) and All Risk insurances, Cargo, Marine and Construction policies usually have coverage on to the Insured due to typhoon events. It is understood that some products have listed force majeure or typhoon as exclusions. Business owners need to ensure their policies and agreed liabilities have typhoon coverage. The Insured are usually required to report timely to their Insurers after a catastrophe event.
Lockton China’s Risk Solutions team has been working hard to advise clients on typhoon hazard and prevention, knowledge of these climate events, risk aversion methods, introduction to insurance claims and solutions for businesses. We hope this article will help you in dealing with preparation work and risk prevention against typhoon events.
For more information, please contact our risk experts.
