Lifespan, planning & solar · Calculator

Roofing Project Schedule

Enter the start date, the squares, the material, the pitch, the layers to tear off, the crew, the weather days to allow, whether the crew works weekends and the lead time for permit and materials, and the calculator returns the finish date, the book-by date, the work days and the order of work.

It turns the same hours the labor and time calculators use into dates, skipping weekends unless you say otherwise, so a homeowner can plan around the job and a roofer can give a date that holds.

Updated · See the formula

Roofing Project Schedule

Units

The first day on the roof

squares
layers
workers
days

Days lost to rain or wind; 1 per week of work in spring and autumn

days

For permit, material order and delivery: shown as a "book by" date

Example result for the starting values. Enter your own and press Calculate.

Expected finish

2026-10-12

3 working days from 2026-10-08 including 1 for weather

Work days
2
Weather
1
Book by
2026-09-24
The schedule
Book byThu, Sep 24, 2026 (14 days ahead for permit and materials)
StartThu, Oct 8, 2026
Work days1.13 crew days + setup → 2
Weather days1
FinishMon, Oct 12, 2026 (3 working days)
Show the arithmetic
  1. Hours = tear-off 9.6 + install 26.4; crew day = 4 × 8 = 32 h
  2. Days = round up (1.13 + 0.25 setup) = 2 + 1 weather = 3
  • Never tear off more than the crew can dry in before the day ends or the next rain; a schedule that ignores this is how roofs leak during a reroof.
  • Shingle sealant strips need warm sun to bond; in cold weather the manufacturer may require hand-sealing, which adds time.

Order of work

  • 1. Tear-off and deck repairs, a section at a time: about 0.3 crew days
  • 2. Dry-in the same day: drip edge at the eaves, ice barrier, underlayment, drip edge at the rakes
  • 3. Flashing, valleys and vents as each area is covered
  • 4. Roofing: about 0.8 crew days
  • 5. Ridge vent and ridge cap, final flashing, cleanup and magnetic nail sweep
  • 6. Final inspection if the permit requires one

Understanding your result

The headline is the expected finish date, with the working days and weather days. The stats give the work days, weather days and book-by date. The table is the schedule; the list is the order of work.

The hours behind the work days are the same as the roofing time calculator and the labor calculator, so all three agree. Whether to reroof now is a question for the replacement planner, and the price for the replacement cost calculator.

How we calculate this

tear-off hours = squares × layers × tear-off rate × pitch factor install hours = squares × hours per square × pitch factor work days = round up ((tear-off + install) ÷ (crew × 8) + 0.25 setup) total days = work days + weather days finish = start + total days − 1, counting working days (or calendar days with weekends) book by = start − lead time

The assumptions behind the numbers

Assumption Default Where it comes from
Hours per square by material Roofing estimating practice
Crew day 8 hours Standard
Setup and cleanup a quarter day Estimating practice
Weather 1 day A judgement; one per working week in spring and autumn
Lead time 14 days Permit and material order

Assumptions last reviewed October 7, 2026.

The calculator does not know local holidays, permit turnaround or inspection wait times. The safety guide explains why steep work goes slower.

Two worked examples

A shingle reroof starting Monday, October 12, 2026

24 squares, walkable, one layer, crew of 4, 1 weather day, weekdays only.

  • Hours: 9.6 tear-off + 26.4 install = 36; 1.13 crew days + setup → 2 work days
  • With weather: 3 working days; finish Wednesday, October 14, 2026
  • Book by Monday, September 28

A steep slate roof starting Thursday, October 15, 2026

24 squares, steep, crew of 4, 2 weather days.

  • Hours: 31.2 tear-off + 187.2 install; 6.83 crew days + setup → 8 work days
  • With weather: 10 working days; finish Wednesday, October 28, 2026

Where to find your inputs

Start date. From the roofer’s calendar.

Squares and material. From the quote.

Crew. Ask the roofer.

Common mistakes

  • No weather days. Something always rains.
  • Booking too late. Permits take time.
  • Tearing off too much at once. Dry in daily.
  • Ignoring weekends. Most crews work weekdays.
  • Cold-weather sealing. Hand-sealing adds time.
  • No inspection time. Some jurisdictions inspect before final.

Questions people ask

How long does a roof replacement take from start to finish?
A 24-square walkable asphalt reroof with one layer off is two working days for a crew of four, three with a day for weather: a job starting Monday October 12, 2026 finishes Wednesday the 14th. Heavy materials and steep roofs take a week or two.
How far ahead should I book a roofer?
Allow two weeks or more for the permit and the material order, longer in the busy season after storms; the calculator shows the book-by date.
What is the order of work on a reroof?
Tear-off and deck repairs a section at a time; dry-in the same day with drip edge at the eaves, ice barrier and underlayment, then drip edge at the rakes; flashing, valleys and vents; the roofing; ridge vent and cap; cleanup and a magnetic nail sweep; final inspection.
How many weather days should I allow?
About one per week of work in spring and autumn, fewer in a dry summer. Tear-off never starts with rain forecast.
Do roofers work weekends?
Some do, especially in the busy season; tick the box and the schedule counts calendar days.
Can I stay in the house during a reroof?
Usually yes, with noise, dust in the attic and nails in the yard. Move cars, cover attic belongings and keep children and pets away from the drop zone.
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