JM Construction Group, LLC
- Roofing Contractor serving Janesville, Wisconsin — based at 425 E Milwaukee St, Janesville, WI 53545.
- Jobs on the listing: roof replacement, storm damage repair, roof inspection, roof repair, emergency repair.
Services Offered
Looking up JM Construction Group, LLC in Wisconsin
Wisconsin roofing-license requirements are not yet covered by our verification program — confirm licensing and insurance with your city or county building department
- Start the lookup with the license number; use the business name only if the number fails.
- Request a current certificate of insurance from the insurer; licenses and insurance are checked separately.
- The registry name, the contract name and the truck lettering should all agree; the status should be active.
- Write down the expiry and make sure it outlasts the job.
Storm record for Janesville and Rock County
NOAA's Storm Events file contains 63 hail entries for Rock County since 2017. Hail of quarter size or larger came down on 19 different days. 3 of those days had golf-ball hail or larger. The largest stone was 2.75 inches, roughly a baseball. Golf-ball hail shows up last in the data in 2026.
NOAA also lists 15 tornadoes here, the strongest rated EF2.
Among 50 Wisconsin counties with enough reports to compare, Rock County ranks 8 by density: 101.9 reports per 1,000 square miles, upper-third territory.
Thunderstorm wind peaked at 85 mph in the record.
68 percent of reports fall between April and July, and April alone has 31 percent. 5 months of the year are nearly hail-free on file.
Date your photos after each hail day and keep them. A written inspection from JM Construction Group, LLC or any other roofer is worth asking for before work starts.
| Measure | Value |
|---|---|
| Hail reports, all years | 74 |
| Hail density rank in state | 8 of 50 |
| Tornado reports on file | 15 |
| Highest gust, mph | 85 |
| Biggest stone, inches | 2.75 |
| Days at 1.75 inches or more | 3 |
The record's top day is April 18, 2025: a 2.75-inch stone, about the size of a baseball, reported near Evansville.
| Calendar year | Entries | Top size, in |
|---|---|---|
| 2014 | 5 | 1.75 |
| 2016 | 4 | 1 |
| 2025 | 18 | 2.75 |
Who lives under these roofs
Half the homes in Janesville predate 1972; the typical house is about 54 years old. Pre-1980 construction makes up 63.2 percent of homes in Janesville. Set a typical $10,575 asphalt job beside the $209,700 median home value and the roof comes to 5 percent.
| Measure | Value |
|---|---|
| Housing units | 29,171 |
| Typical year built | 1972 |
| Median household income | $71,664 |
| Homes lived in by owners | 66.5% |
| Detached and attached houses | 73.7% |
Roof prices in Janesville
The Janesville multiplier is below 1, about 6 percent lower than the national basis, giving $6,580 to $14,570 for asphalt shingles. The county holds 21 roofing establishments with employees, per the Census. 76.2 percent of them have fewer than 5 employees. Divide price by years of life and the ranking changes: see the last column.
| Material | Price range | Service life | Yearly cost |
|---|---|---|---|
| TPO / EPDM (Flat) | $7,520 to $15,040 | 15-25 yrs | $560 |
| Metal Shingles | $13,160 to $22,560 | 35-50 yrs | $420 |
| Concrete Tile | $14,100 to $25,380 | 40-50 yrs | $440 |
| Metal (Steel/Aluminum) | $15,980 to $28,200 | 40-70 yrs | $400 |
| Standing Seam Metal | $22,560 to $37,600 | 50-70 yrs | $500 |
| Clay Tile | $22,560 to $37,600 | 50-100 yrs | $400 |
Asked about roofing in Janesville
- What is the biggest hail on record for Rock County?
- The largest stone since 2017 measured 2.75 inches, about the size of a baseball. 3 days reached golf-ball size or more.
- Is hail common around Janesville?
- 63 reports since 2017, 19 days at 1 inch or larger, and the busiest month is April.
- When is hail season in Janesville?
- Hail concentrates in April (31 percent), and April through July total 68 percent of the record.
- What should I budget for a new roof near Janesville?
- Count on $6,580 to $14,570 for a standard asphalt job in Janesville; the middle is $10,575.
- How old are homes in Janesville?
- Median year built is 1972, which gives 54 years. A roof is younger than the house whenever it was replaced.
- How do I check JM Construction Group, LLC's license?
- The Wisconsin lookup shows status and expiry. Compare both with the contract and ask the roofer for proof of insurance.
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