Why roofs fail
Old stock, much of it split into flats, warmed by somebody who is not the owner. The roof absorbs all three of those facts.
- 1 The ridge. One ridge over two households, and one of them pays to replace it.
- 2 The field. The part everyone looks at, and rarely the part that actually failed.
- 3 Valleys. Most of them were cut in later, when the house was divided into flats.
- 4 The chimney. Often two of them, and often neither one carries anything any more.
- 5 Penetrations. Two kitchens and two bathrooms mean twice the holes on the same roof.
- 6 The overhang. Where heat from a flat you do not control comes back down as ice.
The six
- Heat you don’t controlThe heat that wrecks the roof is not yours
- Ridge vent, no intakeA ridge vent with nothing feeding it
- Very old stockNothing here is the age it looks
- Converted housesThe house was cut up, and the roof shows it
- Disused chimneysThe chimney that stopped working years ago
- Twice the holesTwo households, twice the holes
Old houses, and other people’s heat
The heat that wrecks a roof here is usually somebody else's: a top-floor tenant sets the thermostat, and the landlord owns the ice it makes at the eave. A ridge vent added to a house whose soffits were never opened vents nothing. Nothing here is the age it looks, because a covering laid over an older one resets the surface and not the deck. Houses cut into apartments carry roofs that were cut with them. Chimneys that stopped serving anything decades ago still punch through the roof, and a two-family puts twice the holes in one covering. The roof pays for decisions made downstairs.