Three estimates for the same roof can come back thousands of dollars apart, and the cheapest is not always the lowest price. It is often the one that left things out. Here is what a proper roofing estimate spells out, and what to ask about anything yours does not.
The scope: what exactly is being done
The estimate should say whether the old roof is being torn off or covered over. A tear-off costs more and is almost always the right job, because it is the only way to see and replace bad decking. It should say how many layers are coming off, since a second layer under the first is more labor and more disposal. And it should name every slope and section included, so a porch roof or a flat section over the kitchen is not discovered to be extra on the day.
The materials, by name
Not "architectural shingles" but the manufacturer and the product line, because they are not all the same. The underlayment. The ice and water barrier, and how far up from the eave it runs (on Long Island, past the warm wall line, and in every valley). The drip edge. The ridge vent and any other ventilation. The flashing, and whether existing flashing is being reused or replaced. Pipe boots. Starter strip. Ridge cap. A line that says "all necessary materials" is not a line.
Decking
Nobody knows how much decking is bad until the shingles are off. A good estimate says so, gives a price per sheet to replace what is found, and tells you the crew will show you the bad sheets before they go in the dumpster. An estimate that is silent on decking is one that will have a conversation about it on day two.
What is included around the roof
Gutters off and back on, or left in place? Satellite dishes and solar panels? Skylights reflashed, or replaced? The chimney flashing rebuilt, or caulked? Attic ventilation improved, or left as is? Each of these is a real cost and a real decision, and they should be on the paper, in or out.
The job itself
How the house and the plantings will be protected. Where the dumpster goes. Magnetic nail sweep of the lawn and the driveway at the end. Debris removal and disposal. Permits, and who pulls them. A start window and how long the job takes; most residential roofs are three to five days.
Licensing, insurance and warranty
The estimate should carry the company's license number, and the company should be willing to show a current certificate of insurance, both liability and workers' compensation. If a worker is hurt on an uninsured job it can come back to the homeowner. It should state the manufacturer's warranty on the materials and the contractor's own warranty on the workmanship, which is the one that covers how it was installed. Ours is three years.
Payment
A deposit is normal; a large one up front is not. Payment tied to milestones, with the balance due on completion and your approval, is the usual shape. Be wary of anyone who wants it all before the shingles arrive.
Comparing estimates
Line them up by scope, not by total. If one is much lower, find the thing it does not include: often it is the tear-off, the ice and water barrier, the decking allowance or the flashing. If one is much higher, ask what it buys. Then ask each roofer the same question: how long have you been doing this here, and who will I call in five years if something is wrong? The answer to that is worth more than the difference in the numbers.
Our estimates are free, written, itemized and usually in your hands the same day as the visit.
