Understanding your result
The headline is the saving after valuing your time, or the extra cost if DIY comes out dearer. The stats give the cash outlay, your hours and the break-even rate; the bars compare DIY cash, DIY with your time and the quote.
The number to think about is the break-even: the cash saving per hour of your work. Your hours come from the roofing time calculator times three or four; the ladder from the ladder length calculator; and the quote can be checked with the cost per square calculator.
How we calculate this
The pro worker-hours are the same estimating figures the labor calculator uses; the factor of 3.5 for a first-time roofer is a judgement, so enter your own if you have done it before.
The assumptions behind the numbers
| Assumption | Default | Where it comes from |
|---|---|---|
| DIY hours | 3.5 × a pro crew’s worker-hours | A judgement for a first-time roofer |
| Value of your time | $30 per hour | Enter your own |
| Tools and safety | $600 | Typical rental of a nail gun, compressor, roof jacks, harness and anchors for a week |
| Safety | OSHA fall protection | OSHA 29 CFR 1926 Subpart M, applied in spirit |
Assumptions last reviewed October 7, 2026.
The calculator does not price injury, a leak from a half-finished roof in a storm, or the warranty difference. The safety guide covers when not to go up at all.
Two worked examples
A 20-square ranch reroof
Materials $3,800, dumpster $450, tools $600, permit $300, quote $13,500, time at $30.
- DIY cash: $5,150; hours: 105 (estimate)
- Saving: 13,500 − (5,150 + 3,150) = $5,200; break-even $79.52 per hour
A 12-square garage
Materials $2,300, dumpster $350, tools $400, permit $150, quote $7,800, time at $25.
- DIY cash: $3,200; hours: 63
- Saving: $3,025; break-even $73.02 per hour
Where to find your inputs
Materials. From the quantity calculators and a supplier’s prices.
Quote. From a contractor, ideally three.
Your hours. From the time calculator times 3.5, or your own experience.
Common mistakes
- Leaving your time at zero. It is the biggest cost.
- Forgetting rentals and disposal. They add up to a thousand dollars.
- No fall protection. Anchors and a harness.
- Working alone. Never.
- Tearing off more than you can cover. Dry in every day.
- Steep or high roofs. Hire them out.
Questions people ask
- How much can I save by roofing my own house?
- Roughly the labor share of the quote, minus rentals and your time. On a 20-square architectural shingle roof quoted at $13,500 with about $5,150 of materials, disposal, tools and permit, the cash saving is $8,350; valuing about 105 of your hours at $30 leaves $5,200.
- How long does it take a homeowner to reroof?
- Three to four times a professional crew's worker-hours: about 100 hours for a 20-square shingle roof with one layer off, which is two to three weekends for two people if the weather holds.
- Is DIY roofing safe?
- It is one of the riskier home projects. Falls from roofs and ladders are a leading cause of construction fatalities in the US according to OSHA. Use anchors and a harness, never work alone, stay off wet or steep roofs, and hire out anything above a walkable pitch or a single storey.
- Do I lose the warranty doing it myself?
- You keep the basic manufacturer material warranty in most cases, but you lose the contractor's workmanship warranty, and the enhanced system warranties usually require a certified installer.
- Do I need a permit to reroof my own house?
- Most jurisdictions require a permit for a reroof whoever does it, and some require the owner to live in the house to pull an owner-builder permit. Check with the building department.
- What is the break-even hourly rate?
- The cash saving divided by your hours: the hourly value of your time at which DIY saves nothing. If you earn more than that per hour elsewhere, or value your weekends more, hire it out.