Most asphalt roof replacements in Janesville run about $8,500 to $18,500+, depending on size, pitch, tear-off layers and materials. Most homes take about a day on site, and your exact price comes from a free inspection and estimate.
When a Janesville roof is past fixing, Martin Exteriors Roofing & Siding tears it off and builds a new one from the deck up. We have served the Stateline since 2006 from our Roscoe office at 11704 Main St, about 35 minutes down I-39/90. Call (815) 624-6278 any time. Someone picks up 24/7, and the roof inspection is free.
Looking for a roofing contractor in Janesville, WI? Martin Exteriors holds Wisconsin license 1436189, is a GAF Master Elite contractor with 2-Star President’s Club recognition and a Certified James Hardie installer, and is bonded and insured. Every Janesville roof replacement starts with a free inspection and a written estimate.
Which Roof Is Your Janesville House On?
Census estimates for 2020 to 2024 put the median Janesville home at 1972, and the 1970s were the city’s busiest decade for new houses, with about 17% of today’s homes built then. Add the 1960s and roughly a third of Janesville went up in those twenty years. Most houses from that stretch have already been reroofed at least once.
A second wave is coming due behind them. About 22% of Janesville homes were built from 1980 through 1999, and plenty of them still wear the roof the builder put on. A first roof tends to give out all at once: curled tabs, bare patches on the sunny slopes and shingles that crack instead of bend when the weather turns cold.
Mid-Century Ranches on the East and North Sides
The long, low ranches on Janesville’s east and north sides are simple roofs, which is good news on tear-off day. A straightforward ranch usually takes a day on site. The catch is the attic. Many ranches from the 1960s and 1970s were built with little intake venting at the eaves, and a short-vented attic bakes shingles in summer and helps ice build along the edges in winter.
So when we replace a ranch roof, the attic gets as much attention as the shingles. We check intake at the soffits and exhaust up high, and if the balance is off, we correct it as part of the job. Our attic ventilation page explains how. We also look hard at the porch and family room additions many ranches picked up over the years, because the joint where an addition meets the house needs its flashing done right.
Older Two-Stories Near Downtown
Roughly 1 in 7 Janesville homes predates 1940, many of them on Courthouse Hill and the streets near the Rock River downtown. These are tall houses with steep pitches, dormers, chimneys and short valleys. They take longer than a ranch, and we tell you that before we start.
Tear-off on a house that old often turns up more than one layer of shingles, or board decking underneath. Your written estimate spells out how any replaced decking is priced, so the day brings no surprises. Old flashing at every chimney, dormer and sidewall comes off with the shingles, and new flashing goes on with the new roof.
Janesville Hail and Tornado History From NOAA Records
Storm damage is a common reason a Janesville roof gets replaced early. NOAA’s Storm Events Database, built from National Weather Service reports and storm surveys, lists these events in and around the city:
- August 2, 2011: hail 2.25 inches across was reported as a storm moved east along State Highway 11 from downtown Janesville.
- May 2, 2018: wind driven hail about 1.5 inches across damaged siding in the Cedar Crest neighborhood and nearby streets.
- June 22, 2024: an EF2 tornado with peak winds near 115 mph crossed the south side of Janesville. NWS surveyors found shingle loss, some lost roof decking and peeled siding along the path, and one house northwest of Burbank Park lost its roof.
- June 25, 2024: quarter to half dollar size hail fell at several spots around the city.
- April 2, 2026: hail up to 1.5 inches across was reported north of downtown.
- April 17, 2026: hail about 1.5 inches across fell just west of downtown.
If a storm went through your neighborhood, a free inspection with dated photos is the place to start. See hail damage roof repair in Janesville, or Janesville siding if the walls took hits too. Call (815) 624-6278.
Source: NOAA NCEI Storm Events Database; each date above links to its event record.
What Goes Into a New Janesville Roof
Every replacement is a full roof system, not just new shingles. All old layers come off down to the deck and soft boards get replaced. Then come ice and water barrier along the eaves and in the valleys, underlayment, drip edge, new flashing, vents and your shingles, installed the way the manufacturer specifies. Many homeowners pick architectural asphalt shingles for the thicker, layered look.
On a brick ranch, the shingle color carries the whole front of the house. We bring full-size samples so you can see them against your brick, trim and siding in daylight before you choose.
Warranty and Paying for It
As a GAF Master Elite contractor, a status GAF gives to fewer than 2% of roofing contractors, we can offer a 50-year GAF warranty with up to 30 years on workmanship on qualifying roofs (GAF eligibility rules apply). Financing is available with payments as low as $149/month for qualified buyers. If you want to know what moves the price of a roof, our roof replacement cost guide walks through it.
A Roofer With a Track Record
Martin Exteriors holds GAF Master Elite status with 2-Star President’s Club recognition. We have made the Inc. 5000 four times (2021 to 2024), and we were voted What Rocks Rockford Best Roofer, 7 years running (2020 to 2026). We install roofs weather permitting, and the phone is answered 24/7.
Signs Your Janesville Roof Needs Replacing
- Shingles are curling, cracked or missing in more than one spot.
- Bare patches where the grit has worn off, or a lot of that grit in your gutters.
- Soft or sagging spots along the roofline.
- Leaks or ceiling stains that come back after a repair.
- Ice builds up along the eaves every winter.
- A second layer of shingles was laid over the first.
Not sure if your roof is past repair? The inspection is free. Our post on warning signs a roof needs replacing goes deeper.
How Much Does a Roof Replacement Cost in Janesville, WI?
Most full asphalt roof replacements in Janesville run about $8,500 to $18,500+, depending on the house type and the roof’s condition.
Mid century ranches on the east and north sides and older two stories near downtown often land in different parts of that range. What affects the price of a Janesville roof:
- Roof area. A long ranch roof and a tall two story differ a lot in squares.
- Pitch. Steeper downtown roofs take more time.
- Tear off layers. More layers mean more labor and haul away.
- Decking. Replaced decking is priced in your written estimate.
- Shingle line. GAF architectural shingles cost less than premium lines or metal.
- Ventilation, flashing and extras. Venting fixes, flashing and other extras add to the total.
What a Free Janesville Estimate Includes
- A free roof and attic inspection with photos.
- A written estimate that spells out decking prices.
- GAF warranty options explained, including a 50-year GAF warranty with up to 30 years on workmanship (GAF eligibility rules apply).
Schedule a free inspection or call (815) 624-6278.
Other Janesville Pages
Start at our Janesville roofing page for everything we do in town. If one spot is leaking and the rest of the roof is sound, see Janesville roof repair. After a storm, our hail damage roof repair in Janesville page covers what to look for. Our main roof replacement page shows how we build every roof. Ready for a look? Schedule your free inspection or call (815) 624-6278. Just north, see roof replacement in Milton.
Recent Roof and Siding Replacement in Janesville, WI
On a full exterior refresh in Janesville, we paired GAF Timberline HDZ shingles in Birchwood with Norandex Cedar Knolls vinyl siding in Deep Water. See the Janesville roof and siding before and after.
Janesville Roof Replacement FAQ
What does a new roof cost in Janesville?
Most full asphalt roof replacements in Janesville run about $8,500 to $18,500+. The house type, roof size and pitch, layers, decking, the shingle line and extras like venting decide where yours falls. A free inspection gets you a written estimate.
Why does my Janesville ranch need attic venting work with a new roof?
Many 1960s and 1970s ranches were built with little intake at the eaves. Without it, heat and moisture sit in the attic, which wears shingles faster and helps ice form at the edges. We check intake and exhaust on every replacement and fix what is short.
Can you replace a roof in Janesville in the winter?
Yes, weather permitting. Cold days call for extra care when handling and sealing shingles, and we watch the forecast closely, so weather can move your start date.
How do I choose a shingle color for a brick house?
Look at the brick in daylight and pick a shingle that shares one of its darker tones. We bring full-size samples to your Janesville home so you can hold them against the brick, trim and siding before you decide.
Is chimney flashing replaced with a new roof?
Yes. When we replace a roof, the old flashing at chimneys, dormers and walls comes off and new flashing goes on. On Janesville’s older two-stories, that is often where the old roof was letting water in.
Which GAF warranty can my new Janesville roof get?
As a GAF Master Elite contractor, we can offer a 50-year GAF warranty with up to 30 years on workmanship on qualifying roofs (GAF eligibility rules apply). GAF decides which roofs qualify, and we go over your options with you at the estimate.
Do I need a permit to replace my roof in Janesville?
It depends on the job, and the City of Janesville Building Division handles permits. The city requires a building permit for structural alterations, so a reroof needs one when the roof framing will be altered. If your house is in the Historic Overlay District, any exterior work, roof replacement included, needs a Certificate of Appropriateness before the building permit is issued. Martin Exteriors pulls and handles all required permits, so you have nothing to file yourself. See the City of Janesville residential building permits page.
Is Martin Exteriors a licensed roofing contractor in Wisconsin?
Yes. We hold Wisconsin license 1436189 and Illinois roofing license 104.017824, and we are bonded and insured. We are a GAF Master Elite contractor with 2-Star President’s Club recognition, and we will show proof of insurance on request.
Will insurance pay for a new Janesville roof after hail or wind?
That depends on your policy and what your insurer finds after a storm. We meet your adjuster at the house, review the estimate with you line by line, and prepare and submit supplements when damage was missed, with you approving each step. You file the claim and pay your deductible, and your insurance company decides what is covered. See insurance claim help.
Will a new roof stop ice dams on my Janesville house?
A new roof helps a lot, but ice dams start in the attic. Warm air leaks up, melts the snow on the roof, and the water refreezes at the cold eaves. On every Janesville roof replacement we install ice and water barrier along the eaves and in the valleys, and we check the attic’s intake and exhaust venting and correct it as part of the job if the balance is off. If you have ice dams or a winter leak right now, see our ice dam repair page.
