Serving both O’Fallon, Illinois (62269) and O’Fallon, Missouri? Yes! Our crews work on both sides of the river. Whether you’re in Metro East or St. Charles County, Gallagher Bros has you covered.
Metro East gets hit hard by spring and summer storms. Hail, high winds, and severe weather can damage shingles, gutters, and flashing without warning. If you’ve noticed missing shingles, water stains on your ceiling, or debris in your yard after a storm, call us for a free inspection. We work directly with your insurance company to make the claims process as smooth as possible.
Most roofs in the O’Fallon, Illinois area last 20-25 years before they need replacement. If your roof is aging, showing signs of wear, or you’re seeing granules in your gutters, it may be time for a new roof. We offer GAF and Owens Corning shingles with manufacturer warranties, plus our own 5-year workmanship guarantee.
Buying or selling a home in O’Fallon, IL? A professional roof inspection gives you peace of mind and negotiating power. We provide detailed inspection reports that document the condition of your roof, remaining lifespan, and any issues that need attention.
EXCELLENT Based on 650 reviews Posted on VICKIE VALENTINETrustindex verifies that the original source of the review is Google. Gallagher Bros. did all the replacements to my roof, siding, gutters, and downspouts from the storm 3/14/25. Willie Wyninegar was my contact person. What a great guy. Very personable and knows his stuff. They dealt with the insurance company which was very helpful.I would highly recommend them. Their work is great quality and absolutely worth going with them. Vickie ValentinePosted on Sandy SilveyTrustindex verifies that the original source of the review is Google. Posted on Trina CornellTrustindex verifies that the original source of the review is Google. We had severe hail damage to our roof and siding from the spring storms of 2025. Gallagher Bros. Construction was recommended to us as a great company to use. We truly had a great experience working with Rex and the work crews that came to replace our roof and siding. Both projects, with the roof in November and the siding in February, were completed within the span of two days. Both jobs were done extremely well! The best part about working with Gallagher is their work with the insurance companies. They worked on our behalf to help us get the maximum amount of money we needed from our insurance to pay for the work completed. Everything was handled professionally from start to finish - and we could not be happier with the work completed! We will definitely be recommending Gallagher Bros. Construction to anyone that needs their services - and we would love to work with them again if the need arises!Posted on Joe ChickTrustindex verifies that the original source of the review is Google. Rob and the crew at Gallagher bros did an excellent job replacing my roof. I appreciated their attention to details, quality work, and clean up efforts. I would definitely recommend them to any homeowner!Posted on Jerry BehanTrustindex verifies that the original source of the review is Google. Bob and team with Gallagher Bros were friendly to withvthroughought the roofing and gutter replacement process.Posted on Catherine JochensTrustindex verifies that the original source of the review is Google. I can’t say enough great things about Gallagher and Bob Halstead. Bob is very personable, knowledgeable and straight up. I was pleased with the amount of coverage we got from insurance due to hail damage, and Bob was instrumental in assisting with that. All in all, I give them my highest recommendation, and we are so pleased with our new roof!Posted on Rex WashburnTrustindex verifies that the original source of the review is Google. What a great experience! Bob and Gallagher Bros made a new roof effortless. They were partners the entire way and the quality of work was perfect!Posted on Kevin walkerTrustindex verifies that the original source of the review is Google. Great company to work with. Very easy process to have roof replaced after storm damage. Bob had great customer service and kept us informed during the whole process.Posted on Jacob PlankTrustindex verifies that the original source of the review is Google. Great workVerified by TrustindexTrustindex verified badge is the Universal Symbol of Trust. Only the greatest companies can get the verified badge who has a review score above 4.5, based on customer reviews over the past 12 months. Read more