Note what can be revamped, and what will need replacing. If some shingles are older but still functional, they can be weather-proofed to prolong use. (Older shingles that have brittled are not safe for further layering, and are pointless to waterproof, replace them when necessary.)
Waterproof your roof. This can be done one of two ways: waterproofing under the shingles, or waterproofing over them. If you’re investing in a new roof installation or replacing an old one, you’ll want to waterproof under the shingles. Including sub-shingle weather-proofing during installment will help it last much longer. Layered materials between rafters and shingles – tar paper, roofing felt, or thermoplastic polyolefin – that create the combined capabilities of keeping moisture out and reducing condensation in the attic – are key to maintaining a strong roof.
However, if expensive repairs are a moot point for you; your roof is worn but not badly damaged; or you’re managing limited budgetary constraints; waterproofing over the shingles may be best for you. To restore shingles’ waterproofing oils or resins, simply roll or spray a waterproofing compound directly onto them.
Keep in mind, if your underlayment is not already waterproof, applying these compounds is a fruitless effort. If this is the case, it is recommended that you weather-proof to the fullest extent possible by installing under-shingle waterproofing reinforcements.
Storm-proof your roof. Named notoriously as “roof eaters,” tropical storms and hurricanes can wreak havoc on an unprotected roof.
With a shingled roof, regular inspections are crucial. Brittled shingles are damage-prone, and will tear and lift off in strong winds. If sturdy shingles remain, use six nails per shingle to secure them; replace all others that have worn. Verify the integrity of your roof’s shingles before installing a new layer on top, as worn shingles, even beneath a layer of brand new ones, significantly lower a roof’s wind rating.
For the DIYer, you’ll need a ladder, putty knife, and caulking gun. Have a friend spot you while using the ladder. Assuming some flexibility in the shingles, apply the adhesive to their underside. Using your foot, press down firmly on each shingle to ensure full contact with the adhesive.
Coastal residents especially will need to reinforce their roofs against strong winds. The best remedy is prevention; arrange for regular inspections to verify your roof will perform as needed. Due to specificity of materials (stainless steel flashing, hot dipped nails) and recommended inspections, it is best to hire a roofing company.