When most people think of a roof replacement, they only think of the shingles. The main structure of the roof can also suffer damages that will require a replacement.
Parts of the Main Structure
The main structure of your roof consists of the decking and the supports. Decking, also known as roof sheathing or cladding, is typically made of thick plywood or a similar compressed wood material. The deck is what makes up the main structure of your roof to which the shingles are attached. The decking is a virtually unbroken surface, with the only penetrations through it being for vents, chimneys, and similar devices.
The decking is held in place by the main trusses, which can be made of wood or metal. These form the skeleton or framework of the roof. Perpendicular to the trusses and running horizontally are the joists. Joists provide additional support for the trusses as well as the weight of the roof. The joists will also support the floor of the attic and the ceiling drywall beneath.
Signs of Structural Damage
The most common type of structural damage is from impacts, particularly those that penetrate through the decking. Falling branches or entire trees are the likely culprits, although impacts from anything that is heavy enough or driven at high velocity can be a problem. These damages are usually obvious because the impact that pierces the decking will lead to immediate water entry into the home.
Other damages are more likely the result of slow leaks, which can lead to water damage and rot on decking, as well as on wooden trusses or joists. Hardware failure can also affect the roof structure, particularly trusses and joists. Ground movement can pull trusses out of square or even break the hardware so they are no longer secured properly. This is a common problem in areas prone to hurricane-force winds or earthquakes.
Solutions and Repairs
Impact damages, particularly those that break through the decking, almost always require a new replacement roof. The affected decking boards must be replaced along with the shingles. Water rot on decking will also require a full roof replacement of both decking and shingles, as well as water damage mitigation in the attic and insulation.
Damaged joists may need replacement, as well, particularly if wood rot has set in. The same is true of wooden trusses. Depending on the extent of the damage, the roof may need to be removed and rebuilt completely, or only the damage to the joists may require repairs. If wind or earth movement has been an issue, your roofing contractor will likely install hurricane strapping to prevent future structural problems.
Contact a roof replacement service if you suspect that major damage has affected your roof's structure.