Quick answer: A full roof replacement isn't just new shingles laid over the old ones. It's tear-off down to bare decking, a decking inspection and repair, ice-and-water shield at eaves and valleys, synthetic underlayment across the whole deck, new drip edge and flashing, ridge and soffit ventilation, the shingle system itself, and a real cleanup with a magnetic nail sweep. If a bid doesn't price those out as separate line items, that's the question to ask before you sign.
Homeowners call us all the time thinking "roof replacement" means one thing — tear off the old shingles, nail down new ones, done. That's part of it, but it's maybe a third of what's actually included in a roof replacement done right. The rest happens under the shingles, where you'll never see it once the job's finished, which is exactly why it's the part that gets quietly skipped on a lowball bid. We're going to walk you through every line item that belongs in a proper tear-off, from the dumpster showing up to the last magnet pass across your lawn, so you know what you're paying for and what a bid is leaving out.
What's actually included in a full roof replacement?
A proper full roof replacement includes tear-off and haul-away, a decking inspection with any rotted boards replaced, ice-and-water shield at the vulnerable spots, synthetic underlayment over the whole deck, new drip edge and flashing, ridge and soffit ventilation, the shingle system with starter strip and ridge cap, cleanup with a magnetic nail sweep, and the permit and warranty paperwork behind it. Here's the line-by-line breakdown.
| Line item | What it actually covers |
|---|---|
| Tear-off & haul-away | Every layer of old shingles, felt, and nails stripped to bare decking; dumpster and disposal fees |
| Decking inspection & repair | Soft, delaminated, or rotted plywood boards cut out and replaced before anything goes back down |
| Ice-and-water shield | Self-adhering membrane at eaves, valleys, and penetrations — your real defense against Illinois ice dams |
| Synthetic underlayment | Water-resistant layer across the entire deck, not just the field of the roof |
| Drip edge & flashing | New metal at every edge, chimney, wall, and valley — the parts that stop 90% of real leaks |
| Ventilation | Ridge vent and soffit intake so the attic can actually breathe under the new roof |
| Shingle system | Starter strip, field shingles, and ridge cap installed to manufacturer nailing specs |
| Cleanup & nail sweep | Tarps at the foundation during tear-off, then a full magnetic sweep of the yard and driveway |
| Permit & warranty registration | Municipal permit pulled, and your manufacturer warranty registered in your name, not left undone |
Why do we tear the whole roof off instead of layering over it?
Because you can't inspect, repair, or properly flash a deck you can't see, and layering just buries whatever's already wrong with it. Illinois building code caps re-roofing at two layers of shingles for a reason — each layer adds weight, traps moisture between layers, and makes it impossible to catch a soft or rotted board until it fails. A full tear-off strips every layer down to bare decking, which is the only way to actually see what you're building the new roof on top of. It's more work and it costs more than a layover, but it's also the only version of "roof replacement" that starts the clock over instead of hiding a problem for the next guy to find.
What's happening under your new shingles that you'll never see?
Four things go down before a single shingle does: the decking gets checked and any bad boards get swapped, ice-and-water shield goes on at the eaves and valleys, synthetic underlayment covers the rest of the deck, and new drip edge and flashing go in at every edge and penetration. This is the part of the job that decides whether your roof leaks in year three or holds for twenty-five, and it's also the part a homeowner standing in the driveway can't verify just by looking at the finished shingles.
Ice-and-water shield matters more here than in most of the country. Chicago-area winters mean freeze-thaw cycles that back snowmelt up under the shingle edge as an ice dam, and a self-adhering membrane at the eaves and valleys is what stops that meltwater from finding its way into your attic. Skip it, or skimp it to just the eaves and skip the valleys, and you've saved maybe a couple hundred dollars on a roof that's going to leak the first hard freeze-thaw winter it sees. Decking is the other one that gets shortcut on a cheap bid, because replacing a rotted board takes time and material a low bid didn't budget for — so a corner-cutting crew nails right over a soft spot and hopes you don't notice for a few years.
Cheap tear-off vs a proper one — what actually gets skipped
The shingles on top can look identical between a $9,000 bid and a $14,000 bid. The difference lives entirely in the line items underneath, and it's the reason we tell homeowners to ask for a written, itemized scope before comparing any two numbers side by side.
| Corner cut on a lowball bid | What it costs you later |
|---|---|
| No decking replacement, even where it's soft | Sagging, delamination, and a new roof nailed to rotted wood |
| Ice-and-water shield skipped or only at the eaves | Ice-dam leaks into the attic the first bad freeze-thaw winter |
| Old flashing reused instead of replaced | Leaks at chimneys, walls, and valleys within a few seasons |
| No ridge or soffit ventilation added | Baked attic in summer, ice dams in winter, shortened shingle life |
| No dumpster or magnetic nail sweep | Nails in your lawn, your tires, and your kids' bare feet for months |
Why is ventilation part of the job, not an upsell?
Because a roof without proper intake and exhaust airflow cooks itself from underneath, regardless of how good the shingles on top are. Ridge vent along the peak and soffit vents at the eaves let hot, moist attic air escape instead of baking the underside of your new decking all summer and feeding ice dams all winter. Manufacturers factor ventilation into their warranty terms for exactly this reason — a shingle rated for 30 years in a properly vented attic can fail a decade early in one that isn't breathing. If a bid doesn't mention ventilation at all, ask why.
How long does a full roof replacement actually take?
Most single-family homes in the Chicago suburbs take one to three days from tear-off to final cleanup, depending on roof size, pitch, and how much decking needs replacing. A straightforward 2,000-square-foot roof with a good crew often wraps in a single day; a steep, cut-up roof with rotted decking to swap out can stretch to three. Weather is the real wildcard — we don't tear off a roof we can't dry in and shingle the same day if rain's moving in, because an open deck overnight is exactly the kind of risk a rushed crew takes and a careful one doesn't.
What should be itemized on your contract before you sign?
A contract that's just a total price and a signature line tells you nothing about what you're actually buying. Before you sign anything, make sure these are spelled out in writing:
- Tear-off to bare decking, with disposal included — not a layover
- Decking repair terms: a per-board price or a cap, so a "surprise" mid-job charge isn't a blank check
- Ice-and-water shield coverage — specifically where (eaves only, or eaves and valleys)
- Underlayment type and coverage across the full deck
- Flashing scope — new versus reused at chimneys, walls, and valleys
- Ventilation being added or upgraded, if your current attic needs it
- Shingle manufacturer, product line, and color, plus who registers the warranty
- Cleanup scope, including a magnetic nail sweep of the yard and driveway
- Permit responsibility — who pulls it and who's listed on it
The cleanup that actually matters
A roof replacement tears thousands of nails and shingle fragments loose over your yard, driveway, and landscaping, and the cleanup is the part homeowners judge us on almost as much as the roof itself. We tarp the foundation before tear-off starts to catch debris before it hits your beds and window wells, then run a magnetic roller across the entire yard, driveway, and street frontage at the end of the job — not a quick pass, a real one, because a single roofing nail in a bike tire or a bare foot is the kind of thing that turns a good job into a bad review. If a crew is already packing up the truck five minutes after the last shingle goes on, ask where the magnet is.
Frequently asked questions
Does a roof replacement always mean tear-off, or can you go over the old shingles?
A true full replacement always means tear-off to bare decking. Illinois code allows layering a second layer of shingles over one existing layer in some cases, but that's a re-roof, not a replacement, and it skips the decking inspection and ice-and-water shield that make a real replacement worth the money.
How do I know if a roof replacement bid is missing line items?
Ask for the scope broken down by line item — tear-off, decking terms, ice-and-water shield coverage, underlayment, flashing, ventilation, and cleanup — instead of a single total. A legitimate bid can answer each one specifically; a bid built to win on price alone tends to get vague fast once you ask what's actually included.
Does replacing my roof automatically include new gutters or ventilation?
Ventilation upgrades like ridge and soffit vents are typically part of a proper roof replacement scope. Gutters usually aren't — they're a separate system, though it's common to bundle a gutter replacement into the same job if yours are old or damaged, since the crew and equipment are already on-site.
What warranty should I expect on a full roof replacement?
Expect two separate warranties: a manufacturer warranty on the shingles themselves (often 25–50 years depending on the product line) and a workmanship warranty from your contractor covering installation. Make sure the manufacturer warranty gets registered in your name — that step gets skipped more often than you'd think.
Want the line-by-line version for your own roof? Book a free inspection and we'll walk your roof and put every item in writing before you sign anything. See how we run the job from tear-off to final sweep on our process page, browse residential roofing systems we install, or ask about financing options if you're spreading out the cost. We serve homeowners across the north and northwest Chicago suburbs, including Arlington Heights, Buffalo Grove, and Northbrook — or just reach out with questions. For what all this actually costs in this market, see our guide on roof replacement costs in the Chicago suburbs, and if you're not sure you need a full replacement at all, read how we decide between repair and replacement.