What is due on a roof that several households share

The parts of a roof age on different schedules, and on a divided house some of them were installed when the flats were, not when the roof was. Enter when the house was built and what has been replaced since, and it will show where each part stands.

This is a guide to where to look, not a finding about the roof. It sets ages against the service lives the trade generally expects. A roof over a cold attic can outlast the range; one over a top flat heated by a tenant can fall short of it every winter. Who heats the top floor matters more than the year.

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Set the house, then mark what has been done

When was the house built? What is on the roof now?

What has already been replaced?

Leave a row on Original if that part has never been replaced, or if a previous owner may have done it and nothing came with the deed. On a house that has changed hands this often, not knowing is the rule.

Roof covering Flashing at walls, valleys and penetrations Underlayment and ice-and-water shield Gutters and downspouts Attic ventilation Skylights (if you have them) Chimney crown, cap and masonry (if you have them) Fascia and soffit Siding or exterior cladding Window seals

A three-family roof takes its orders from the apartments below it. It gives out where the heat gets out. Which is why flashing, not shingle, is the item most worth knowing the age of.

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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.

Why a new shingle can sit on a roof the tenants have been heating for decades

When a roof is laid over the previous one, the surface is new and the underlayment beneath it is whatever was there. On a divided house that membrane may be older than the division. The visible part resets; the working part does not. That is why this page asks about underlayment on its own line, and why on many of these buildings the honest answer is that no one knows when the deck was last exposed.

Flashing works the same way, and here it is worse, because the dormers were cut in later and flashed to whatever was already there. Sealing that metal is faster than rebuilding it, and it happens often enough that a roof from five years ago can be relying on flashing fitted when the house was split. If someone says the roof is recent, ask about the dormers.

Use this page

Copy or link to this freely, crediting pawtuxetroofing.com. If it helps the owner of a divided house in Providence or Warwick see what the top flat has been doing to the roof, it has done its job.

Already have quotes for the building? The comparison checklist sets up to three of them side by side, row for row.