Repair or Replace: Making the Call on an Old Roof

When an old roof starts giving trouble, the question is always the same: do we patch it up again, or bite the bullet and replace it? Spend too soon and you've wasted money on a roof that had years left. Leave it too long and you're paying to fix water damage on top of the roof itself. Here's how we weigh it up.

The age of the roof is the starting point. Every roofing material has a rough lifespan. A long-run steel roof is generally good for 30 to 40 years, concrete and clay tiles can run 50 years or more, and asphalt shingles wear out sooner. If your roof is well within its expected life and the problem is isolated, repair is almost always the right call. If it's at or past its use-by date and starting to fail in more than one place, you're into replacement territory, because fixing one spot just shifts the next leak along.

The extent of the damage matters as much as the age. A few cracked tiles, a single rusted patch, or a leak traced to one failed flashing are all straightforward repairs on an otherwise sound roof. But widespread rust across the sheets, multiple leak points, or damage that turns up in a new spot every time it rains tells you the roof has reached the end as a whole. The test we use is simple: is this one problem, or is the whole roof tired? One problem gets repaired. A tired roof gets replaced.

Then there's the money, and it's worth being clear-eyed about it. Repairs are cheaper up front, no question. But if you find yourself calling a roofer every winter and spending a few hundred dollars each time on patch jobs, those repairs add up fast, and you've still got an old roof at the end of it. At some point the running total of repairs would have gone a long way towards a new roof that gives you decades of peace of mind. Add up what you've spent over the last few years before you decide.

Don't forget the cost of what's underneath. The real danger with limping an old roof along is that water gets past it and into the structure. Once it's rotting framing, soaking insulation or staining ceilings, you're paying to fix that damage on top of the roof, and structural repairs are far more expensive than roofing. A roof that's actively leaking in several places is doing damage you can't see, and that changes the maths in favour of replacing sooner.

There's also the bigger picture to consider. If you're planning to sell soon, a sound roof or a recent re-roof is a strong selling point and a tired roof is a red flag to buyers. If you're staying put for the long haul, a new roof you never have to think about for thirty years is often worth more than a string of cheaper fixes.

The honest answer comes down to the specific roof in front of us, and a good roofer will tell you straight rather than push the bigger job. As a rule, repair a sound roof with an isolated problem, and replace an old roof that's failing across the board or letting water into the structure. If you're caught in the middle and not sure which it is, get someone up there to give you a proper assessment, because the right call is usually obvious once you can see the real condition.