Verified record
Cahill Roofing Inc. is a Hollis-based roofing contractor that says it has been in business since 1994 and has completed thousands of roofing projects. The company says it serves southern New Hampshire and northern Massachusetts, offers free estimates, and handles residential and commercial roofing along with related exterior work. The customer history is substantial for a single platform: 23 Google reviews from 2022 through 2026, with a 4.9-star platform rating from 29 ratings. Homeowners describe roof replacements, garage and portico roofing, repairs, ridge caps, chimney flashing, roof vents, gutters and ice-dam-related work. Recent reviews praise clear explanations, prompt scheduling and careful repairs; older reviews repeatedly mention competitive estimates, cleanup, material and project guidance, and crews protecting gardens and walkways. There is one serious account to discuss before booking. In an April 2024 review, a homeowner described concerns about a 19-year-old roof installation and said Cahill was defensive, denied an issue before reviewing it, and did not engage with an independent analysis. That review is sharply at odds with the many positive accounts, so ask how callbacks, inspections and workmanship concerns are handled, especially on older roofs. Cahill looks best suited to homeowners seeking roof repair or replacement in the Hollis–Nashua area who value direct owner involvement and a detailed estimate. Confirm the exact scope, ventilation or decking needs, cleanup plan, warranty terms and how any post-installation concern will be handled.
A few years ago, I had Mark Cahill do some repair work on my roof. While that job was small, his attention to detail was spot on and all issues were addressed. When it came time to do a full roof replacement, I was very confident in choosing Mark for the job, and his execution completely exceeded my expectations. From the start, we went through the roofing materials and associated project options, and everything was presented in a clear, concise manner. During the actual job, our home was treated with the highest level of respect. Debris was promptly cleaned up by Mark and his team, and the yard was consistently left in a safe state at the end of each day. Because we had elected to also take on some siding repair, the project naturally took a bit longer. Maintaining that 'clean yard' approach every single day is a great example of the level of service you get with Mark and his crew. The quality of the end result is excellent. A new roof is a major investment, and I have complete peace of mind knowing no corners were cut.
I had a new roof installed 5 years ago but the installer went out of business. I was concerned about the quality of installation and could see a raised shingle. They did a roof inspection and made several repairs - clearly verbally describing and documenting them - assuring me that otherwise the roof was in good condition. Absolutely perfect service!
The owner Mark Cahill personally came by my house yesterday after speaking with him in the morning. I spoke with him on the phone and he was both pleasant and professional. I told him that I needed a roof rain diverter over the front door to keep the rain from dripping on people's heads and he gave me an instant quote and was at my house in a matter of a couple of hours. He was great to talk with and he explained what he was going to do and even asked my wife and I if we had an questions or preferences concerning the job. He did the job promptly and even volunteered to removed a Dish Satellite Disk from the roof. I would highly recommend Mark and will most certainly use his talent and services again when needed. He deserves the Five Star review. Thank you again Mark. Regards, Al Migneault
Cahill Roofing did our roof replacement and external home repair. Outstanding quality and workmanship. FIVE STAR.
Cahill Roofing recently replaced my roof, and I’m thrilled with the results. I chose them because of Mark's extensive experience and reputation. They addressed issues with the roof decking and added soffit and ridge venting to improve airflow. The team was professional, efficient, and kept me updated throughout the process. I highly recommend them!
Specializes in
Also offers
Service area
Languages
1 change recorded — last scanned Sep 14, 2026.
Honest assessments5.0