How to compare roofing quotes line by line

Homeowners who collect three roofing quotes often end up with three very different documents. One is a single page with a total. One is four pages of line items. One arrives as a text message. Comparing them by the total alone makes it easy to choose a quote for a different job from the one you need.

Settle the size of the roof first, then line the quotes up one item at a time, and ask about every gap.

Settle the size of the roof first

Every quote should state how many squares it prices. If it does not, ask. This number underpins the rest of the quote, and it is where quotes most often disagree.

If one quote says 24 squares and another says 29, they are not pricing the same job. One may include waste. One may include the garage. One may be a rough estimate. Ask each contractor how they measured and what the figure includes. The arithmetic behind a square count is covered in roof pitch and roofing squares explained.

Compare prices against one trusted square count

Choose one measurement you trust. That might be a measured diagram or an aerial report you have checked, or a count on which two independent methods agree. Then divide every quote's total by that same square count. Do not divide each quote by its own square count.

Dividing by a quote's own figure hides the difference you are trying to find. A quote that pads its square count looks cheap per square, and a quote that counts short looks expensive, even when the totals say the opposite.

Here is an example. The trusted measurement is 24 squares. Quote A totals $14,400 and prices 24 squares. Quote B totals $15,950 and prices 29 squares. Divided by their own counts, A comes to $600 per square and B to $550, so B looks cheaper. Divided by the same 24 squares, A is still $600 but B is about $665, so B costs more for the same roof. The next step is to ask B what the extra five squares are for.

Price per square is still a rough guide. Quotes differ in materials and scope, so work through the items below before drawing conclusions.

The line items to compare

Tear-off and disposal

A new roof either goes over one old layer or replaces it. Check which each quote assumes. A tear-off quote should say how many layers are being removed and whether disposal is included. Extra layers found once work starts are a common source of added cost, so a careful quote gives a price per extra layer in advance.

Decking

Nobody knows the condition of all the decking until the old roof is off. Most quotes therefore include a price per sheet for replacing damaged decking, and some include an allowance for a few sheets. Compare the price per sheet across quotes. A low total with an expensive price per sheet can end up costing more than it first appears.

Underlayment and ice and water membrane

Under the shingles is a layer called underlayment. Asphalt-saturated felt is the traditional underlayment and is still used; many roofs now use synthetic underlayment. Synthetic sheets are lighter and tear less easily. Check what each quote uses.

Where ice dams are a known risk, codes commonly require a self-adhering ice and water membrane along the eaves, and many roofers also use it in valleys. Check where each quote puts it and how far up from the edge it runs. Some quotes go beyond the code minimum, which costs more for a reason.

Flashing

This is the line most often missing. A quote should say whether the step flashing, chimney flashing, pipe boots and valley metal are new or reused. Reusing sound, heavy flashing can be fine. Reusing cracked pipe boots on a new roof is not. What flashing is, and why leaks often start there explains why this line matters.

Starter strip, ridge cap and drip edge

These are ordered by the linear foot from the eave, rake, ridge and hip lengths, not from the square count. Check that each quote includes them and says whether the drip edge is new.

Ventilation

A roof lasts longer with air moving through the attic. Quotes may include ridge vents, new intake vents at the eaves, or replacement fans. If one quote includes ventilation work and another does not, ask the second contractor whether they looked at it.

The shingles

Check the product line and style, not only the manufacturer. Most manufacturers make several grades, and the differences in price and expected life are real. If a quote only says architectural shingles, ask which ones, and ask for the color name so you know it is still made.

Warranty, permits and payment

The last lines of a quote are easy to skim and worth reading slowly.

• Workmanship warranty. How many years does the contractor stand behind the installation, and is that in writing?
• Manufacturer warranty. Is it the standard coverage, or an extended one that depends on particular components, a certified installer or registration?
• Permits. Who applies for the permit, and is the fee included?
• Cleanup. Is a magnetic sweep of the yard and driveway for nails included?
• Payment. Never pay the full price upfront. A modest deposit with the balance tied to progress or completion is common, and some states limit how large a deposit can be.

Build a comparison sheet

1. Make one column for each quote.
2. In the first rows, write the trusted square count, each quote's own square count, each total, and each total divided by the trusted count.
3. Add a row for every line item above.
4. Fill in what each quote says, and mark a question wherever it is silent.
5. Ask each contractor about their open questions, in writing if you can.

Most contractors are glad to answer, and clear, patient answers to careful questions are a good sign.

When the lowest quote is the right one

Sometimes the lowest price is the best one. It may come from a smaller firm with lower overhead, or from a contractor with a gap in the schedule. Lining quotes up is not about ruling out the cheapest. It is about confirming that the cheapest prices the same roof, with comparable materials, as the others. If it does, and the license, insurance, warranty and payment terms check out, there is no reason to avoid it.