What one layer weighs
Architectural asphalt shingles run about 250 pounds per square per layer. A 19-square roof is about 4,800 pounds, 2.4 tons, per layer. Two layers is nearly five tons. Slate, tile and old heavy three-tabs weigh more; check before you size the dumpster.
What one layer costs, on a 19-square roof
| Tear-off time: 19.2 squares ÷ 30 per crew-day | 0.64 crew-days |
| Labor: 0.64 × $950 | $608 |
| Equipment: 0.64 × 8 hrs × $18 | $92 |
| Overhead: 0.64 × $262.50 | $168 |
| Dumpster: 2.4 tons, one 3-ton box | $425 |
| Direct cost per layer | $1,293 |
|---|---|
| Priced at 35% margin | $1,989, about $104 a square |
Those are the defaults in the free roofing estimate calculator. Change the layer count there and watch the dumpster count and crew-days move.
Why the second layer can cost more than the first
The first layer of debris often fits in one dumpster. The second pushes you over and buys a second box for a fraction of a load. On this roof, one layer is 2.4 tons in one 3-ton dumpster; two layers is 4.8 tons and needs two. Round dumpster counts up; never assume a half-full box will stretch.
Count the layers before you quote
- Lift a shingle at the eave or rake edge and count the courses.
- Look at the drip edge: a thick, stepped edge usually means more than one layer.
- Check the attic for sagging decking that suggests extra weight.
Decking is a separate line
Tear-off exposes rotten or delaminated decking you could not see. Price replacement per sheet on the quote, typically installed at a set price per 4 × 8 sheet, and state that the base price assumes sound decking. Never absorb it into the per-square price. The price per square guide shows where tear-off sits among the other lines.
