The Homeowner’s Guide to Asphalt Shingle Roof Replacement

Posted on 2026-03-06 23:42:14

An asphalt shingle roof rarely fails all at once. More often you notice the small tells first, a line of curled tabs along the southern slope, grit from the shingles building up in the gutters, a dark shadow where the decking is sagging under old plywood. If you are seeing two or three of those signs, it is time to take a hard look at a roof replacement rather than chasing spot fixes. I have walked more homeowners through this decision than I can count, and the same questions always surface. How long does a new roof last, what does it cost, and how do you avoid paying twice to fix the same mistake?

Replacing asphalt shingles is not exotic work, but it does demand judgment. The right choice on underlayment, ventilation, and flashing will add years to the system, while the wrong one will guarantee you are calling a roofing contractor for a leak when the next nor’easter or hailstorm rolls through. This guide strips away the slogans and gets into the practical decisions that make a roof last.

When repair makes sense, and when to replace

Not every issue needs a new roof. A broken boot at a plumbing vent or a piece of loose step flashing along a dormer is a classic case for a straightforward roof repair. A few shingles torn by wind can be swapped if the surrounding field is still pliable and color matched, and if the roof is under 10 years old you might even have material coverage for the replacement shingles.

The balance shifts when age and widespread wear appear. If you are seeing granule loss that exposes the shingle mat across multiple slopes, or you can pinch a shingle and it cracks rather than bends, the roof is at the end of its service life. You can keep chasing leaks on a 20 to 25 year old three-tab roof, but every patch becomes a finger in the dam. In my experience, once more than 20 percent of a slope shows cupping or loss of mineral surface, replacement is the economical choice. Insurance adjusters tend to use similar thresholds after wind or hail events, and roofing repair companies will often advise the same once repairs become serial rather than surgical.

There is also the question of underlying damage. If you have ice dam staining on the soffits, or your attic shows black fungal spotting on the underside of the sheathing, you likely have a ventilation or insulation issue that a simple repair will not fix. A roof installation that addresses those root causes prevents repeating the cycle.

What affects cost, realistically

National averages hide a lot of variation. For a straightforward one-story ranch with a walkable pitch and architectural shingles, full tear-off and replacement might run 5 to 8 dollars per square foot in many markets, which puts a 2,000 square foot roof between 10,000 and 16,000 dollars. Factors that push numbers up or down are simple, but they stack quickly.

Pitch and access matter more than homeowners expect. A 10 in 12 roof demands staging and more labor time. Carriers prefer ground loads and forkliftable driveways, not backyard hand carries around a pool. Complex roofs with multiple valleys and dormers rack up hours in flashing and cut waste. Then there are local code requirements. Some jurisdictions mandate ice and water shield from the eaves up to 24 inches inside the warm wall, others require it across entire valleys or in high wind zones. Material choices change the math as well. A Class 4 impact rated shingle typically adds 30 to 60 dollars per square, but many insurers offer premium discounts that recover that cost over a few years.

Most roofing companies build in decking contingencies because no one knows the state of the plywood until the old roof is off. A common approach is to include a set number of sheets at a flat rate, then charge per sheet after that. If you see soft spots when you walk the roof, or if your home still has 3/8 inch plywood, expect a few hundred dollars of decking correction per area. It is not an upsell, it is the structure that holds the fasteners.

Tear-off versus overlay

Every few months a homeowner asks if they can avoid the mess by installing a new roof over the old one. Building codes in most areas allow at most two layers of asphalt shingles, and many roofing contractors will not install over an existing layer at all. Here is why. Overlays trap heat, which ages the new shingles faster. They add weight, not usually enough to worry a modern structure, but older homes with undersized rafters can deflect. More importantly, you cannot correct flashing or decking issues you cannot see, and those are the biggest leak points. An overlay saves on disposal and tear-off labor, maybe 70 to 120 dollars per square, but it almost always shortens the new roof’s life. If you plan to stay https://sites.google.com/view/roofing-contractor-godfrey-il/roofing-contractors in the home longer than five to seven years, a full tear-off is the better call.

There is one narrow exception. On a very low slope porch roof, where a future remodel will remove the structure within a few years, a careful overlay can be a temporary solution. On the main house, it is a false economy.

Getting the scope right

A good scope of work is not a menu of brand names, it is a clear description of how water will be managed from ridge to gutter. When I build a scope for a roof replacement, I make sure the following elements are explicit.

Drip edge at all eaves and rakes, with proper overlap at joints, is non-negotiable. In some older homes it was never installed, and wind-driven rain at the edge causes rot in the first few inches of decking. Underlayment should be identified by type and location. Most roofs use a synthetic underlayment on the field for its tear resistance, with ice and water shield at the eaves, valleys, and around penetrations. In snow country, the ice barrier should extend from the eaves to at least two feet inside the heated interior line. Valleys deserve a line or two of their own. An open metal valley with a W profile sheds debris and snow well, while a closed cut valley is clean looking but relies entirely on shingle layering. Both work if installed correctly, but the choice should be candid, not a surprise on install day.

Flashing details matter more than the brand of shingles. Chimneys need counter flashing cut into the mortar, not surface applied flashing with caulk. Skylights should be evaluated for replacement if they are out of warranty or show failed seals, since reusing old skylight flashing rarely ends well. Step flashing along walls and dormers should be replaced, not left in place under new shingles, and the siding above should be loosened to tuck the flashing correctly. Finally, ventilation needs to be matched to intake. A ridge vent without soffit intake will pull conditioned air through light fixtures rather than the eaves, which is a recipe for ice dams and high energy bills.

Shingles, classes, and choosing what is worth it

Architectural, or laminated, shingles dominate the market because they balance cost and performance. The thicker profile adds weight and wind resistance compared to three-tab shingles, and warranties reflect that with limited lifetime language that, in practice, covers manufacturing defects with proration schedules. The meaningful distinctions are in impact and wind ratings. If you live under frequent hail, a UL 2218 Class 4 shingle resists bruising that fractures the mat. Insurers in many states discount premiums 5 to 15 percent for Class 4 roofs. In coastal or high-wind regions, look for shingles rated under ASTM D7158 at Class H, which corresponds to 150 mph wind resistance when installed per spec, including the correct number of nails and placement.

Color and algae resistance are not just aesthetics. Lighter colors reflect more heat, which helps in hot climates, and algae resistant copper or zinc granules curb the black streaks common on north-facing slopes in humid areas. Expect algae resistance to hold for 10 to 15 years before nature wins.

For homeowners weighing upgrades, I advise this simple rubric. Pay for better ventilation and flashing before you spend on the top-tier shingle. An entry-grade architectural shingle installed over a well-ventilated deck with meticulous flashing will outlast a premium shingle laid over a starved attic and reused flashing.

The role of ventilation and insulation

Roof systems last longer when the attic temperature and humidity stay close to outdoor conditions. The old rule of thumb is 1 square foot of net free ventilation for every 300 square feet of attic floor area when a balanced system is in place. Balance means roughly equal intake at the soffits and exhaust at the ridge. In practice, many homes are short on intake because soffit vents are painted shut or insulation is choking the airflow. Before a roof installation, check that baffles are in place at the eaves to keep the insulation from blocking the airflow. Box vents and gable vents can supplement ridge vents on chopped-up roofs, but avoid mixing exhaust types without a plan. An active power vent can short-circuit a nearby ridge vent and pull conditioned air from the house if intake is weak.

Insulation complements ventilation by reducing heat loss into the attic. In cold regions, bringing the attic floor up to R-49 or higher helps to prevent ice dams. In warm regions, a radiant barrier and proper ridge-to-soffit flow cut cooling loads. When I find moldy sheathing, it is almost always poor ventilation paired with bathroom fans discharging into the attic rather than out a roof cap. Fixing that during a roof replacement adds little time but solves a chronic problem.

Picking the right roofing contractor

Plenty of roofing companies can nail shingles in a straight line. The difference shows up in the details you do not see from the curb. Experience with your roof type, clear scope documentation, and a culture of correcting hidden issues rather than covering them define the better crews. Ask how the crew handles decking repairs if they uncover rot. Listen for specific answers, not vague reassurances. The same goes for flashing. If the answer to a chimney question is a quick mention of caulk, keep looking.

Paperwork matters too. You want a written warranty from the contractor that covers workmanship for a defined period, often 5 to 10 years, plus the manufacturer’s limited warranty on materials. Some manufacturers offer extended warranties if the installer is certified and uses a full system of branded components. Those can be worth it, especially if you plan to hold the property and want a single point of contact if something fails. Verify that the roofing contractor is insured and licensed where required, and that permits will be pulled under their name, not yours.

Price comparisons are tricky because scopes vary. When two bids differ by more than 25 percent, dig into what is included. One may be reusing flashing, skipping ice barrier in valleys, or omitting ventilation corrections. Roofing repair companies sometimes bid low on a replacement to keep a crew busy, then change order their way back to market price. That is not always bad faith. Unknowns truly exist under old shingles. It is your job to set the expectation that you want photos of any hidden condition and a unit price, per sheet of decking or per linear foot of flashing, before work starts.

Preparing your home and schedule

A typical single-family roof, 2,000 to 3,000 square feet with simple geometry, takes a crew one long day to tear off and dry-in, then a second day to shingle and detail. Complex roofs or weather delays stretch that timeline. Crews often arrive early and work until dusk, so plan for noise. Park vehicles away from the house to keep access clear for the dump trailer and material delivery. Inside, remove fragile items from walls and shelves, footfall on the roof vibrates through the framing. Protect attic contents with tarps if you store valuables up there, especially during tear-off when dust and debris can fall through gaps.

Pets and kids need a plan. Yard magnets will be used to pick up nails, but the first 48 hours after a tear-off are the highest risk for a missed fastener in the grass or driveway. I have watched more than one neighbor puncture a tire by hugging the curb during a roofing job next door.

The day of installation, and what to watch

The best crews work in a rhythm, a clean tear-off down to bright wood, an immediate dry-in, and then a methodical rebuild from eaves to ridge. If you are home, a quick walk with the foreman in the morning helps. Confirm that the right shingle and underlayment showed up. If you specified open metal valleys, you should see coil stock or pre-bent valley metal on site. If your home needs new drip edge color matched to the fascia, inspect a piece before it goes up.

You do not need to hover, but checking a few details is reasonable. Nail patterns are an easy tell. Six nails per shingle at the manufacturer’s line are standard for higher wind ratings, and installers should not be shooting high, which cuts the shingle rather than fastening through the double thickness. Flashing at penetrations should be integrated with the underlayment and shingle courses, not smeared with sealant as the primary defense. Good crews use sealant sparingly, as a supplement.

A clean site during the work is a good predictor of a clean, durable roof. Dump tarps, frequent magnet sweeps, and organized staging keep the project on track. If rain threatens, a crew that pays attention will leave the roof buttoned up with underlayment, not gamble on a half-open valley at the end of the day.

Here is a short homeowner’s checklist that keeps you focused on the essentials without getting in the crew’s way:

Verify materials match the contract: shingle model and color, underlayment types, ridge vent style. Confirm drip edge is being installed at eaves and rakes, with ice barrier at eaves and valleys where specified. Ask for photos of any decking replacement before and after, with the count of sheets documented. Look for proper nail placement and count on a sample course, then let the crew work. Walk the property with the foreman at the end for a punch list and magnet sweep.

Handling surprises the right way

Hidden layers are common in older homes, sometimes two layers of shingles over a brittle cedar shake base. When the shakes come up, the decking beneath is often spaced boards rather than modern plywood. Code generally allows shingle installation over spaced sheathing if the gaps are small, but most manufacturers want a solid deck under their shingles for proper fastener hold. The practical fix is to sheath over the boards with 7/16 inch OSB or 1/2 inch plywood. That adds cost and time, but it stabilizes the system and protects your warranty.

Skylights deserve a second mention. If the glazing shows fogging or the frame is out of square, replacing it during the roof project is cheaper than doing it later. Reflashing an old, marginal unit is a recipe for callbacks. The same applies to chimneys with crumbling mortar. You cannot cut and embed counter flashing into sand, so addressing masonry before or during roofing avoids a temporary patch.

After the last shingle, what good workmanship looks like

When the crew rolls off, good workmanship reveals itself in the edges and intersections. The shingle courses should align cleanly at ridges and hips without stair-stepping. Valleys should be straight, with no exposed fasteners in the flow line. Drip edge should sit tight to the fascia, with seams lapped in the direction of water flow. At the ridge, look for a continuous vent with uniform cap shingles, not a mix of pieces. In the attic, you should see minimal daylight through the decking, only at intake vents by design. If you had mold or staining before, take reference photos to compare in a few months as ventilation does its work.

Paperwork is part of the finish. Ask for a final invoice that lists any change orders and decking sheets replaced. Keep a copy of the permit closeout and inspection, if your jurisdiction requires it. Register the manufacturer’s warranty if it needs homeowner action. I have watched warranties lapse because the postcard never left the kitchen drawer.

Understanding warranties and what they do not cover

Manufacturer warranties on asphalt shingles cover defects in the product, not mistakes in installation. The phrase limited lifetime feels comforting, but read the proration schedule. Many cover full material replacement in the early years, then step down over time. Labor coverage may be included only if you register an upgraded system with a certified installer. Hail and wind damage are generally insurance matters, not manufacturer warranty items, unless the product did not meet its advertised rating and failed under conditions below that threshold.

A contractor’s workmanship warranty typically covers leaks that arise from how the roof was put together, not from falling branches or a satellite dish improperly installed by a third party. The strongest sign you are working with a reputable roofing contractor is their willingness to return for a minor issue months later without drama. Ask past clients about that, not just about the day of install.

Insurance claims and timing

Storm damage complicates decisions because timing and documentation matter. If wind tears shingles off a 15 year old roof and water intrudes, call your insurer and a trusted contractor quickly. Temporary repairs, tarps and targeted patches, are usually covered to prevent further damage. Adjusters will look for uniformity of damage. Randomly scattered missing shingles suggest repair, while directional tearing on the windward sides indicates replacement. Hail assessments lean on bruise counts in test squares. Impact resistant shingles rarely suffer the same granule displacement and mat fracture as standard shingles, which is one reason many homeowners choose to upgrade after a claim. If your policy offers a discount for Class 4 shingles, ask your agent to document that change on the renewal.

Scheduling after a major storm is a challenge. Roofing companies get overwhelmed, and storm chasers flood the market. That does not mean out-of-town crews are all bad, but you need to know who will stand behind the warranty when the caravan leaves. A deposit should be modest, enough to order materials, not half the contract price. Verify the business address and insurance, and avoid signing a contract that assigns your claim benefits to the contractor without clear opt-out language.

Maintenance that actually preserves a roof

New roofs do not need much, but they are not set-and-forget. Keep gutters clear so water does not back up under the first course. Trim overhanging branches that shade and drip on the roof, especially on the north and east sides where algae thrives. If your home sits under heavy leaf fall, plan on a gentle, low-pressure wash every few years using a cleaner formulated for roofs. Avoid pressure washing asphalt shingles. It strips granules and voids warranties.

Watch penetrations. Rubber pipe boots age faster than shingles and can crack in as little as 7 to 12 years. Replacing a boot is simple work for a roofing repair company and prevents slow attic leaks that ruin insulation and ceilings. After major wind events, walk the property and scan ridges, hips, and edges for lifted caps or exposed nails. Quick attention keeps a small issue from turning into saturated sheathing and interior repairs.

Closing advice from the field

If you strip away the brand labels and sales language, a durable asphalt shingle roof comes down to five disciplines, each of which is under your control when you hire and manage the project.

Tear off to clean decking and correct what you find rather than covering it. Manage water at every edge and joint with proper metal and sequencing, not caulk. Balance intake and exhaust so the roof breathes rather than bakes or sweats. Fasten precisely, with the right nails in the right places, six per shingle where specified. Document choices and conditions so future repairs and resale are straightforward.

Roof replacement is one of the bigger checks a homeowner writes, but it is also one of the most visible and valuable improvements to a property. Choose a roofing contractor who treats the assembly as a system, not a commodity, and you will get the quiet roof that does its job for decades, not a noisy problem that reappears with every season.

Trill Roofing

Business Name: Trill Roofing
Address: 2705 Saint Ambrose Dr Suite 1, Godfrey, IL 62035, United States
Phone: (618) 610-2078
Website: https://trillroofing.com/
Email: [email protected]

Hours:
Monday: 8:00 AM – 5:00 PM
Tuesday: 8:00 AM – 5:00 PM
Wednesday: 8:00 AM – 5:00 PM
Thursday: 8:00 AM – 5:00 PM
Friday: 8:00 AM – 5:00 PM
Saturday: Closed
Sunday: Closed

Plus Code: WRF3+3M Godfrey, Illinois
Google Maps URL: https://maps.app.goo.gl/5EPdYFMJkrCSK5Ts5

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The team at Trill Roofing provides experienced residential and commercial roofing services throughout Godfrey, IL and surrounding communities.

Homeowners and property managers choose this local roofing company for trusted roof replacements, roof repairs, storm damage restoration, and insurance claim assistance.

Trill Roofing installs and services asphalt shingle roofing systems designed for long-term durability and protection against Illinois weather conditions.

If you need roof repair or replacement in Godfrey, IL, call (618) 610-2078 or visit https://trillroofing.com/ to schedule a consultation with a reliable roofing specialist.

View the business location and directions on Google Maps: https://maps.app.goo.gl/5EPdYFMJkrCSK5Ts5 and contact this trusted local contractor for customer-focused roofing solutions.

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Landmarks Near Godfrey, IL

Lewis and Clark Community College
A well-known educational institution serving students throughout the Godfrey and Alton region.

Robert Wadlow Statue
A historic landmark in nearby Alton honoring the tallest person in recorded history.

Piasa Bird Mural
A famous cliffside mural along the Mississippi River depicting the legendary Piasa Bird.

Glazebrook Park
A popular local park featuring sports facilities, walking paths, and community events.

Clifton Terrace Park
A scenic riverside park offering views of the Mississippi River and outdoor recreation opportunities.

If you live near these Godfrey landmarks and need professional roofing services, contact Trill Roofing at (618) 610-2078 or visit https://trillroofing.com/.