What is probably due up there, and what is not

A roof is a set of parts on different clocks, and they rarely reach the end together. Tell it when the house was built, what covers it and what has already been done, and it will show you where each part sits.

This is not a diagnosis and not a prediction. It compares ages against service-life ranges widely used in the trade. A covering can fail at ten years or last past twenty; exposure, ventilation and installation quality matter more than the calendar. Use it to decide what to look at, not what to buy.

Nothing is sent anywhere. This runs entirely in your browser, there is no form, and no information leaves this page.

Check your roof, part by part

When was the house built? What heats and cools it now?

What has already been replaced?

Leave a row as Original if it has never been done, or if it was done before you owned the house and you have no record of it.

The covering itself Fasteners and washers, on exposed-fastener metal Flashings at walls, chimneys and transitions Fasteners, drip edge and valley metal Underlayment The decking Gutters and the roof edge Skylights and other openings (if applicable)

Six places a roof gives way in this valley. On most of them the covering is not what failed. Which is why the boots, the flashings and the hardware are worth knowing the age of, not just the shingles.

Tap to enlarge

1 The ridge cap. On metal it is a separate piece with closures under it. Blown snow finds the joint that was never closed.
2 The seams. A standing-seam roof lives at its seams and clips, not at its surface. The panel outlasts what holds it.
3 The valley. One channel taking what two slopes shed — and on the north side, holding snow long after the field is clear.
4 Where the ell meets the wall. A lower wing dying into the main house. Two roofs, one wall, and nobody sure whose seam it is.
5 The fasteners. Exposed screws through the panel, each with a rubber washer. The washers age; the screws work loose.
6 The eave. Drip edge, gutter, and the question every metal roof asks: where does a slab of snow go when it lets go?

Why the age of the shingles is not the age of the roof

A re-roof usually swaps the covering and keeps much of what surrounds it: flashings sealed rather than rebuilt, hardware reused, vents reinstalled. The field resets; the junctions do not. That is why the tool asks about the flashings and the hardware separately, and why the honest answer for many houses is that nobody knows, because the record of past work left with a previous owner.

The same applies in reverse: a house can carry a young covering over corroded valley metal and brittle boots, and the first ceiling stain will read as shingle failure to everyone who does not climb. If a report blames the field without ever mentioning the metal, the useful follow-up question is what the flashings looked like.

Use this page

This tool may be reproduced or linked to freely, with attribution to susquehannaroofing.com. If it is useful to a homeowners association, a housing counsellor or a community group, it is meant to be shared.

Already have quotes in hand? The quote comparison checklist puts up to three of them side by side on what each one actually includes.