An aging roof
A roof rarely fails on a single day. It gets close over several years, and then one hard spring finds the weakest point. On the Front Range the aging runs faster than the warranty suggests, the altitude sun and the freeze-thaw swings see to that, but it also announces itself, to anyone who knows where to look.
- 1 Ridge caps. Worked loose by a temperature swing that happens every single day.
- 2 The field. High-altitude sun dries the covering out from above, faster than the calendar says.
- 3 Valleys. Where two slopes drain as one, and where meltwater runs longest.
- 4 Flashing. Chimney joints, and the line where the garage roof meets the house.
- 5 The vent boot. Rubber cracks early at this altitude, well before the shingles do.
- 6 Eaves. Ice builds at the edge wherever the attic is leaking heat into the roof.
The signs, roughly in order
Granules in the gutters come first: the mineral armour is leaving and the asphalt beneath is starting to take sun directly. The small rubber boots around plumbing vents crack next: neoprene gives out years before shingle does under this UV load, and a cracked boot is often a roof’s first actual leak. Then come curled edges, ridge caps working loose, and a general brittleness you can hear when a covering is walked late in its life.
The useful question near the end is not “can it be patched” but “what does this year’s decision cost versus next year’s.” Replacing early forfeits a little remaining life; replacing late buys interior repairs on top of the same roof. On subdivision streets where every covering is the same age, the neighbors’ roofs are data: when the street starts turning over, an evaluation of your own is due.
Dating a roof nobody kept the papers for
Most people buy a house without learning when the roof went on, and the disclosure is frequently a guess. There are better sources. Building departments across the metro keep permit records, searchable online in most jurisdictions, and a re-roof pulls a permit: the date on it is the roof’s birthday. Failing that, the covering talks. Three-tab shingles on a subdivision house generally mean an older installation than the thicker architectural profile that took over the market; a continuous ridge vent rather than a row of box vents suggests a more recent tear-off; and the plumbing boots fill in the rest, since neoprene starts cracking after about a decade under this sun.
It is also worth knowing whether there are two layers up there. Roofing over an existing covering was legal and common for a long stretch, and the result runs hotter, ages quicker, and hides whatever the deck was doing underneath it. You can often see it from the ground at the rake, where the roof ends at the gable: two distinct lines of material instead of one. A house with two layers reaches the end sooner than its calendar age suggests, and there is no version of the next replacement that does not involve taking both of them off.