Tampa, FL – December 3, 2010 – (RealEstateRama) — With one of the most active Atlantic Hurricane seasons on record now over, the Institute for Business & Home Safety (IBHS) is encouraging home and business owners to use the cooler months ahead to add hurricane-resistant features to their homes and commercial buildings.
A total of 19 named storms formed in the Atlantic during 2010 – this amount equals 1995 and 1887 for the third highest number on record. Twelve of the named storms became hurricanes, with five reaching major hurricane status of Category 3 or higher.
“The U.S. was extremely fortunate not to suffer a direct landfall hit from one of the storms,” said Julie Rochman, president and CEO of IBHS. “But we cannot rely on good fortune forever. We must prepare our homes, businesses and communities by retrofitting them to better protect against the devastating fury of a hurricane.”
While home and business owners may want to wait until spring to install a new shingle roof because heating the roof cover is required to adequately seal the shingles, there are several that can be done over the winter months. In particular, strengthening the roof structure (which requires attic access) is a great project for months when the attic is cooler.
Recent testing at the IBHS world-class, multi-peril research center in South Carolina clearly demonstrated the importance of protecting openings in older buildings that do not have the steel strapping and continuous load path development required for new buildings in hurricane prone areas.
Doors and Windows
For example, during one test at the IBHS lab, the front door of at test house blew open when winds reached only 95 mph. This conventionally built home was completely destroyed. In a similar, second test of a different conventionally constructed house at about the same wind speed, the entire roof lifted off because of the combination of internal pressure from wind entering the home and the external forces of wind as it blew around the house. To prevent this from happening, homeowners in high-wind prone regions should:
- Provide protection for all glazed openings with approved shutter systems or by replacing the windows with impact rated products
- Replace entry doors with ones rated for pressure and windborne debris impact.
- Outward swinging doors are preferable, because positive pressures actually push them more tightly against the door seals which helps reduce water intrusion and because it is much easier to achieve impact resistance from an outward swinging door. So homeowners should at least consider switching it to an outward swing as opposed to an inward swinging one. Hinges are available that prevent entry by removing the hinge pin.
- Make sure the door is in good condition. Three hinges are recommended.
- Make sure the screws in the hinges are long enough to penetrate the permanent structure at least 1 inch deep.
- The door should have a dead-bolt lock with a minimum 1-inch bolt throw length.
- For double entry doors install heavy-duty barrel bolt sliding latches at the top and bottom. Connect the barrel bolt through the door header and threshold and into the subfloor.
- There are several options for protecting garage doors. They can be replaced with pressure-rated units – some manufacturers have kits that will replace rollers and add bracing so that the door is similar to the new pressure rated units and some home improvement stores carry vertical braces that are code approved and can be installed as extra supports when a hurricane threatens.
- Overhead doors are a typical weak link in most light commercial buildings. If you can’t find any information about the pressure rating of the existing ones, you can reinforce your existing doors similarly as described above for garage doors. You may also consider replacing the doors with impact and pressure rated ones.
Gable end walls and the roof sheathing attached to the gable end continue to be one of the most frequent sources of structural damage. Strengthening of the gable end and the attachment of the sheathing to the framing can be done from inside the attic provided the gable end is at least four feet tall, even if you are not ready to re-roof. This is best done when the attic is cooler and workers can stand to be in the attic for several hours at a time. IBHS has developed detailed guidance on how to effectively retrofit a gable end that has been accepted in the Florida Building Code and will be included in an appendix to the 2012 edition of the International Existing Building Code. Visit the Gable End Bracingpage on http://www.disastersafety.org to access this information and an instructional video on how to install gable end bracing.
Testing at the IBHS Research Center conducted this fall also showed the important role a well-built roof plays in protecting a home. During more than one test, shingles and underlayment began tearing off a home during wind speeds between 50 and 65 mph. Without a secondary water barrier in place, homes are vulnerable to water penetration and damage. To prevent this from happening, when you re-roof:
- Re-secure sheathing with 8d ring shank nails.
- Apply a secondary water barrier.
- Use high-wind rated shingles.
Commercial properties located in hurricane prone areas should have their roof covers inspected for needed repairs. Some repairs may be small; however, depending on the condition of your roof and its remaining useful life, more significant improvements may be needed. Major repairs and new roof installations should be conducted during the off-season hurricane months (December through May).
Modified bitumen and built-up roof cover systems should be inspected for leaks, bubbles, and severe cracking. These can be signs of trapped moisture. A simple moisture survey/thermal scan can determine if the insulation within the cover is wet, and it can measure how bad it is. Single ply membrane roofs should be checked for leaks as well as tears along seams and fasteners, shrinkage, and brittleness. For membrane covers with a parapet, particular attention should be paid to the area where the membrane goes from the deck up the parapet. If there has been shrinkage, the membrane will be overly tight and stretched with a trampoline affect. Conversely, if the membrane is too loose, this may be a sign that the adhesive used has degraded.
Other items that should be inspected for securement is the roof cover’s drip edge / flashing, gutters, and roof mounted equipment. Rusted or corroded materials should be replaced. Inadequately secured roof mounted equipment can be secured to the structural component of the deck such as a steel bar joist using ј in. steel cables, turnbuckles and screws. The additional roof mounted equipment securement should never go directly into a roof deck unless it is verified to be structural concrete.
Keeping the roof attached to the home is critical to its ability to survive a hurricane or any high-wind event. To keep your home’s roof attached:
- As noted above, protecting the openings is one way to reduce the chances that the entire roof will be lost due to the combination of internal and external pressures.
- Uplift resistance can be increased by installing straps to tie the roof to the walls. However, to be really effective, connections need to be improved all the way tothe foundation, and this can be rather intrusive and costly. It is usually most cost effective if it is done as part of a major remodeling project.
“Through testing in our lab we have seen first-hand that these techniques are effective in preventing damage from hurricane-force winds,” said Rochman. “Effective protections for homes and businesses are not mysterious. Building science is clear on what works – and we should make those improvements before the next hurricane season rolls around.”
For commercial properties, this is also the best time to re-evaluate your hurricane plans. If you implemented your plan during this passed hurricane season, take the time to get feedback on its effectiveness. Survey all involved in order to making improvements to the plan. If you haven’t used your plan, you should still review your documented procedures and ensure that it is up to date. Make sure that the plan is well understood by all. Review proper shut down & start up procedures and include necessary training. Check the condition of your supplies and obtain the major supplies needed. It’s also a great time to schedule table top exercises and dry runs of the plan for the first or second quarter of 2011.
IBHS is an independent, nonprofit, scientific and educational organization supported by the property insurance industry. The organization works to reduce the social and economic effects of natural disasters and other risks to residential and commercial property by conducting research and advocating improved construction, maintenance and preparation practices.
Joseph King (813) 675-1045
jking (at) ibhs (dot) org