About Us
Top-Rated Home Improvement Contractors in the Quad Cities
Mainstream Home Improvement has been serving the Quad Cities area since 2001 and has continued to be one of the leading contractors for windows, gutters, roofing, siding, and more. Owner Spencer Sierra has created a precise vision of excellence that has been carried out by our team with every project in the past 20+ years. With experienced staff, high-quality products, and easy-to-understand estimates, we guarantee to provide you with home improvement services that give you total peace of mind. Contact our team today to learn more about our financial options and to schedule a consultation to discuss your home renovation needs.
Our Vision Statement
Our success at Mainstream Home Improvement is centered around our customers. That’s why we dedicate our time and energy to creating meaningful relationships with all past, present, and future clients. We know how important it is for you to have contractors you can rely on when renovating your home, that’s why our team guarantees the best possible service, pricing, and results every single time. Have your project completed to perfection when you trust Mainstream Home Improvement in the Quad Cities area.
We Provide Coverage on Every Project
Regardless of the extensiveness of your project, our contractors at Mainstream Home Improvement are always taking care of your property behind the scenes. We provide property coverage, general liability, automobile, and workers’ compensation insurance on every job site to ensure the safety of everyone and everything involved. Don’t run the risk of trusting a company without the proper insurance or coverage – Mainstream Home Improvement never holds homeowners responsible for accidents while in our care.
Meet Our Team
Spencer Sierra
Spencer was born in Silvis and has spent his whole life here in the Quad Cities. He started Mainstream Home Improvement in 2001. Spencer has been married to his lovely wife, Betsy, since January of 2001. They have two daughters, Rosemary and Ruby. Spencer is passionate about his Catholic faith. He is a devoted parishioner and attends mass daily. In addition to his faith, Spencer enjoys spending time with his family, reading, and listening to the Rolling Stones. His weakness is Whitey’s Ice Cream. He enjoys the Vanilla Oreo shake, slightly melted. (Please don’t try and bribe him because you’ll win.) Spencer’s motto is that he wants to be a great company, period. Not just a great Home Improvement Company.
Marci Boswell
Marci was born and raised in the Quad Cities area and attended High School at Alleman. She studied at Illinois State University. She has been with Mainstream Home Improvement since the first day back in 2001. She most enjoys spending time with her family. She can be found working on projects around her house with her husband Aaron. She is also very active in her son Braydan’s life. Braydan is a great swimmer and Marci loves to watch him. Most of Marci’s family lives in the area and she is grateful for that so she can spend as much time with them as possible. Marci is always cheerful on the phone and eager to help you out when you call Mainstream.
Steve Milbrandt
Steve was born and raised in a small rural community in SE North Dakota. He attended kindergarten through grade 12 with the same 55 classmates. He has been married for 42 years to his lovely wife, Penny. Together they have 2 daughters and 1 very precious grandson. Steve has served customers at Mainstream Home Improvement for over 15 years. He has several more years of experience in the home improvement field, in sales and management. He was also a window manufacturers rep for a major window company.
Steve is passionate about history and identifies as a big WWII buff. He has lived in the same small town of 255 residents just outside of the Quad Cities, for the past 18 years. He and his family enjoy the outdoors and Steve likes to throw a pole in the water anytime it’s not too cold.
You are in good hands with Steve Milbrandt.
Choose Our Contractors for Your Next Project
See Why We’re First Choice for Residents in the Quad Cities.
Our Awards & Achievements
In our 20+ years of business, we are proud to have been awarded for several achievements in the Quad Cities area. On top of these awards, we continue to uphold our industry memberships and charitable contributions to our local communities year after year. Here is an updated list of our most recent awards and reoccurring recognitions.
- Better Business Bureau Integrity Award
- Keeping Rock Island Beautiful Award – Recycling Shingles Program
- SCORE’s Small Business of the Year Award
- Owens® Corning Preferred Contractor
- Featured in the Quad Cities Business Journal Top 40
- Better Business Bureau
- Chamber of Commerce
- The Quad Cities Homebuilder’s Association
- Children’s Therapy Center of the Quad Cities
- Newspapers In Education
- Muscular Dystrophy
- Area Schools
- Area Churches
- Birdies for Charity
- Arrowhead Ranch
- Boy Scouts and Girls Scouts of the Quad Cities
- Area Sporting Teams
- The Quad Cities Marathon
