How to Estimate a Roof Replacement | Reddit & LinkedIn

Roofing is priced in squares, where one square equals 100 square feet. Measure from the ground, from satellite imagery, or on the roof, and record the pitch and the number of stories, because a steep, multi-story roof takes more labor and more safety setup than a walkable ranch of the same area.

Add waste for cuts, valleys, and starter, typically 10 to 15% depending on complexity. A roof with many hips, valleys, and penetrations wastes more material and takes more labor than a simple gable, so your measurement and your labor factor both have to reflect the real shape.

Count the existing layers you will tear off, because two layers is more tear-off labor and more disposal than one. Then inspect the decking, or state that you cannot fully see it until tear-off. Rotten or delaminated decking is the classic roofing surprise that turns a fixed price into a loss.

Handle it with a per-sheet decking allowance: a stated price per sheet of replacement decking that bills only if you find rot. Naming it on the estimate is honest with the client and protects your margin, so a few bad sheets over a bathroom do not come out of your profit.

List the system by component: shingles or panels, underlayment, ice and water shield, flashing, drip edge, ridge vent, and fasteners. A component list lets you match a manufacturer warranty and defend the number against a competitor who quoted one vague line and skimped on the details that matter.

Estimate labor for tear-off, dry-in, install, and cleanup per square, then adjust for pitch, stories, and complexity. Add the dumpster and disposal and the permit as their own lines. These are real costs that a lump-sum guess quietly buries until they eat the job.

Roofing commonly runs 20 to 30% markup on materials over a loaded labor rate, and the exact number reflects your warranty, your crew, and your market. Stand behind a workmanship warranty and price it in, because the cheapest roof is rarely the one a homeowner should buy.

Present a same-day, itemized estimate with the system, the warranty, and a milestone schedule. ContractShield builds this quote from photos in about 25 minutes. Snap the job, say or type the scope, and the AI drafts labor and materials from your own price templates, line by line for you to approve. Every line shows whether the price came from your template or an AI estimate, and it never invents your labor rate or markup. Then the same tool invoices the milestones and chases any overdue balance for you, all for a flat 2% per job, 1% client and 1% contractor, capped at $250 per job, with no per-lead fees ever.