If you live in a hurricane prone state like Florida, then you may have a slate or tile roof that is strong enough to withstand hurricane force winds. However, if you live a little further north, then you may experience hurricane weather only on occasion. If this is true, then you may be able to have an asphalt shingle roof secured on your home. However, you will need to speak to your roofing contractor to make sure the roof sheathing is as secure as possible. Find out why unsecure roof sheathing is an issue and also how your roofing company will prevent an issue when your new roof is installed.
High Winds And Unsecure Sheathing
Roofs are made out of a wood foundation called roof sheathing, and the sheathing is made from either plywood or oriented strand board (OSB). The desired sheathing material is placed over the trusses or rafters of the home. The pieces of sheathing are secured about one-eighth of an inch apart from each other, and nails are angled down into each piece of sheathing about three-eighths of an inch away from each edge. Under normal circumstances, traditional two inch nails can be used to secure the sheathing to the roof beams. These nails are called 8d nails. While the nails do strongly adhere the roof to the home better than the 6d nails that were previously used for roofing, they are still not strong enough to keep the sheathing secured if the strongest hurricane winds blow across your home.
If strong winds, like the over 100 mile per hour wind speeds experienced during two, three, four, and five category hurricanes, then the roof sheathing may be pulled up from the roof. If it is not pulled off completely, the sheathing may be loosened to some degree and lead to leaks.
Better Sheath Securing
If you want an asphalt roof in an area that may experience extreme wind speeds, then the sheathing will need to be attached to the rafters more strongly. If you need brand new roof sheathing, then you should first ask your roofing professional to use plywood instead of OSB. Plywood is stronger than OSB and can retain in integrity under more wind stress. With the correct material, ask your roofer to use long 10d nails instead of 8d varieties to secure the sheathing in place. In some cases, the roofing professional may decide to use screws instead of nails to offer more security.
In addition to using longer nails, the professional will run an adhesive between each piece of sheathing. This will create a bond between the sheathing and the rafters across the entire perimeter of each piece. The same type of adhesive can be used to secure old sheathing on a roof that only requires new shingles. The adhesive used is typically the same type of liquid nail product that is added to the bottom of plywood pieces to create a subfloor. The felt or underlayment applied over the sheathing may be secured with a similar adhesive as well.
When shingles are picked out to apply over the sheathing and the underlayment, make sure the shingles have the correct wind resistance rating. This rating or classification is given to shingles based on the wind speed the shingles are able to withstand. Shingles with an F, G, or H classification are appropriate for homes in areas that experience a good deal of wind speed. Wind resistant shingles are more expensive depending on the protection they provide, so pick the ones that offer the type of protection you need for your area. For example, type F shingles would be a good choice if you experience category two hurricane winds in your area.