The roof is by far the largest and most vulnerable structure on any house. It takes a beating from hail, rain, sun and wind throughout the year, as well as the occasional lightning strike and fallen tree limb.

Despite these everyday hazards, a new roof system can last about 20 years depending on the type of roof covering installed. Some types, such as, clay tile, certain metals like copper, or slate systems can last longer.

Homeowners and homebuilders can improve the life and strength of a home's roof by following a few simple steps. The following are ten techniques that can be used during a roof installation on a new or existing home.

If you are building a new home, the type and shape of the roof can help determine how well it will perform during a severe windstorm. A hipped roof typically performs better in windstorms than a gabled roof because of its aerodynamic properties. A hipped roof slopes upward from all sides of the building. A gabled roof has two slopes that come together to form a ridge or peak at the top, making each end look like the letter A.

Homes with gabled roofs are more likely to suffer damage, such as the collapse of the end wall from high winds, because they are often not braced properly during construction. If your home is built with a gabled end wall, use one of the following construction techniques.

Homes with high, cathedral ceilings, where there is no place to brace a gabled end should be balloon framed. Use full-height studs, concrete or solid masonry walls from the floor below all the way up to the roof. Balloon-framed gable end walls perform better in windstorms because they do not have the hinge that usually exists where the triangular part of the gable sits on top of the wall below.

Brace the intersection of the gable and the end wall. This intersection is a particularly weak point and those that are not properly braced can collapse, causing major damage. In homes with attics, an attic floor or ceiling diaphragm with the proper bracing techniques can be used to provide the lateral support of the gable end wall if the end wall is NOT framed full height, or balloon framed.

Your home's ability to resist the extreme force of wind is only as strong as its weakest link.

The only sure way to create a wind-resistant home is to secure all connections - wall-to-foundation, roof-to-wall, and floor-to-floor.

Install hurricane "straps" or "clips" at every wall-to-rafter (roof joist) connection to reinforce the roof. These connections are critical in holding the roof together and will dramatically increase the home's overall wind resistance. Pay special attention to the reinforcement of gable end connections, which are more likely to fail in high wind. Be sure to install all connectors following manufacturer's specifications.

The roof covering and the deck beneath it are your home's first line of defense from high winds and rain.

Install a roof deck made of solid plywood (not oriented strand board-OSB) that is a minimum of 5/8" thickness to maximize wind and windborne debris resistance. Use 10-penny common or 8-penny ring shank nails to secure the sheathing, nailed every four inches along the panel edges and every six inches in the field of the plywood panel. Make sure the nails penetrate the decking directly into the roof framing. (See diagram below).


Be sure to look in the attic to confirm that the roof decking is properly installed to the roof framing. If you can see nails along the sides of rafters or trusses, where the nail penetrates the decking, your roof deck is probably not securely attached.

Install self-adhering flashing tape or modified polymer bitumen strips (referred to as "peel and seal") to help keep out rain in the event the roof covering blows off during severe weather. Apply the tape to all joints on the plywood deck sheathing.

Install one layer of #30 underlayment (sometimes called "felt paper") over the plywood roof decking and secondary water barrier tape. One layer of #90 underlayment is recommended for tile, slate or metal roof coverings.

Install a roof covering that has been tested to the latest standards for wind and impact resistance. These standards are ASTM D 3161 enhanced or UL 2390 for wind resistance; UL 2218 for impact resistance.

Be sure to specify these standards and look for labels on the products confirming these standards because ordinary roofing materials may not look any different from the wind-resistant versions. Also pay careful attention to the manufacturer's warranty - in some cases, the length of the warranty may have been established as a marketing tool without appropriate technical research or field-testing.

Consider the weather conditions that will most impact your roof. Are you in a hurricane-prone area or in one that is affected by hail? Even one hailstorm can seriously damage your roof's covering. Here are the different types of roof covering materials.

Asphalt shingles are found on most homes in the United States. They can be reinforced with either organic or fiberglass materials. Fiberglass shingles last up to 20 years and have a Class A fire rating. Modified asphalt shingles include SBS (a rubber-type compound) or APP (a plasticizer) and are likely to perform well in hailstorms. Fiberglass composition shingles stand up moderately well to hail. If you live in hurricane prone areas beware: Most asphalt roofing shingles are not rated to withstand winds above 60 mph - well below the minimum hurricane wind speed of 74 mph.

Metal, once considered a commercial roofing material, has now become an attractive alternative for some homeowners. Metal roofs last up to 40 years, are relatively lightweight, and may have a Class A or B fire rating. But unlike other shingles that can ease back into shape, metal shingles can dimple permanently when hit by hail.

Slate can last more than three times longer than shingles but is also more expensive than other materials. Slate is also very heavy. Some roof structures are unable to support this type of roof covering.

Synthetic roof coverings made of fiber cement or molded plastic can simulate the look of various types of traditional roof coverings, such as slate, wood shingles and shakes, but their performance varies by product.

Tile is popular in some areas, but its performance in hailstorms varies by type. Concrete tiles are more durable and can last more than 20 years. Clay tiles are brittle and can be easily chipped or broken. Like slate, tile is heavy. If you replace another type of roof with tile, be sure that the structure can support the weight. Heavy products also can take longer to install, making labor costs significantly higher. Hire a roofing professional experienced in installation of tile and slate.

Wood shingles and shakes are made from cedar, southern pine or other woods. Though some people like their appearance, wood shingles and shakes perform only moderately well against hail. In addition, some local codes limit their use and they may not be rated for fire unless they're treated with a fire retardant. "Class A" roofing materials have the highest resistance to fire that originates from outside the home.

On roof systems at least a year old, you can increase the wind uplift resistance of your roof over nail secured sheathing alone by applying a 1/4 inch bead of APA AFG-01 certified wood adhesive along the intersection of the roof and deck AND roof support elements on both sides of the beam.

During Spring and Fall, look for: shingles that are buckling, curling or blistering; loose material or wear around chimneys, pipes and dormers; and excessive amount of shingle granules in gutters. Granules protect against the elements and ultraviolet rays of the sun. Also be sure to clean the roof and gutters of tree limbs and leaves.