If your old roof is well past the prime replacement date, ongoing leaks may have lead to damages that need to be addressed. Parts of the roof could also be outdated, which means you may need to upgrade the roof during replacement.
1. Is the Support Structure in Good Repair?
If it has been many decades since the last roof replacement, there could be hidden damages to the main structural supports of the roof. Trusses and rafters can crack or bow over time, especially if they have been exposed to moisture from a roof that was in poor repair. The support structure should be fully inspected before the new roof is put on so damages are found and repaired first.
2. Does the Decking Also Require Replacement?
Roof decking can go by different names, such as cladding or sheathing. These all refer to the same thing -- the plywood panels that make up the main roof plane to which the shingles are attached. Decking doesn't always need to be replaced when you have a new roof put on, but if your roof was older or leaking it will need to be assessed for punctures and water damage. If either of these are present, then the decking also requires replacement.
3. Are Current Safety Standards Met?
Safety standards change as new knowledge is gained and new safety products come on the market. You may be required to update wind anchors, sometimes called hurricane straps, at the time of a roof replacement. If snowfall amounts have changed in your area, there may be new requirements on the weight-bearing load of the roof. Your roofing contractor can help point you to new standards and provide advice on whether you should construct the new roof to meet them.
4. Will Accessory Structures Need Replacing?
A roof is more than decking and shingles. There are rooftop penetrations, such as vents and chimneys, that have flashing or booting around them to protect against leaks. Flashing is used in roof valleys, and covers are placed over roof ventilation systems. The eaves are another important roof component that is sometimes overlooked. These will need to be inspected and possibly replaced at the same time as the roof. For example, flashing is nearly always replaced, while eaves may be able to serve multiple roofs.
Contact a roofing service for any additional questions you have about your older roof replacement.