Leaks and flashing
Here the details do not so much wear out as get shaken apart, a fraction of a millimetre at a time, every day for fifteen years.
Roofs rarely fail through the middle of a slope. They fail where the field stops and has to meet something else, and in this climate those junctions are worked loose rather than worn out.
Thermal movement, every single day
A large daily temperature swing means metal flashing expands and contracts against shingles and masonry that expand at different rates. Sealant hardens and cracks. Fasteners back out a fraction at a time until a head sits proud.
Which is why the commonest Pueblo leaks are at:
Pipe boots. The rubber collar around a plumbing vent, hardened by ultraviolet and split by movement. Cheapest fix on the roof and the most commonly deferred.
Chimney and wall flashing. Where a plane meets vertical masonry there should be step flashing under the courses and counter flashing into the mortar. Where somebody once solved it with a rope of roof cement, the cement is now cracked.
Valleys. Debris dams them, and a dammed valley pushes water sideways under the courses.
Fastener heads. Individually trivial, collectively a roof with a shortened life.
The winter problem that is not a leak
In a cold dry climate the failure that most looks like a roof leak often is not one.
Warm moist air rises out of the house into the attic. It meets a deck that is well below freezing. It condenses, wets the sheathing, and in a warm spell it runs and drips. The pattern is damp spread broadly across the underside of the deck rather than tracked from a single point, and it is worst in the cold months.
No amount of roofing work fixes it. The answer is ventilation and sealing the air paths from the house into the attic.
Ice at the eaves
Where an attic leaks heat, snow melts on the warm part of the roof and refreezes at the cold eave, and the ridge of ice that forms holds melt water back until it finds a way under the shingles.
The fix is the same as the condensation fix: insulation and ventilation, so the roof deck stays the temperature it is supposed to be. Ice and water protection at the eaves during a reroof is the belt to that braces.
Questions people ask
- It only leaks when snow melts, not when it rains. Why?
That usually means ice damming or melt water backing up under the shingles rather than running off. It points at the eaves, at ventilation, and at insulation, rather than at a hole in the field.
- There is no stain but the attic is damp in winter. Is that a leak?
Probably not. Warm humid air from the house reaching a cold deck condenses on it. It wets the sheathing, can drip, and no roofing work will stop it. That is ventilation and air sealing.
- Can they find it without waiting for weather?
Usually, with a methodical hose test from low to high. It is slow. A company that will not do it is guessing.