Attic Insulation
Your attic is responsible for up to 25% of your home’s heat loss. We can fix that.
Attic Insulation in St. Louis, MO
Professional attic insulation installation and upgrade in St. Louis, MO. Blown-in, spray foam, and batt options. Improve comfort & cut energy bills. Free estimates.
Why Your Attic Is Your Home's Biggest Energy Liability
The attic is responsible for up to 25% of a home's total heat loss in winter and heat gain in summer. In a St. Louis climate with hot, humid summers and cold winters, an under-insulated attic makes your HVAC system work significantly harder, driving up energy bills year-round. Your air conditioner runs longer to combat the heat pouring through an uninsulated roof, and your furnace cycles continuously trying to replace heat that escapes through the attic floor.
Most homes built before 2000 are well below current recommended insulation levels. If you can see your attic floor joists, or if the insulation is less than 11 inches deep, you're probably losing $50-$200 every month to energy waste. The good news: upgrading attic insulation is one of the most cost-effective home improvements available, with payback periods of 2-4 years in most cases.
Recommended R-Values for St. Louis
St. Louis is located in DOE Climate Zone 4-5, which means your attic insulation should meet specific thermal resistance standards. For uninsulated attics, the Department of Energy recommends R-38 to R-60. For existing insulated attics, we measure the current R-value and add insulation to reach at least R-38 (minimum) or R-49+ (recommended for maximum efficiency and comfort).
Attic Insulation Options We Install
Blown-In Insulation
The most common choice for attic floors. Fast, cost-effective, and ideal for filling irregular spaces. We offer both cellulose and fiberglass options. Installation typically takes one day.
Spray Foam Insulation
Ideal for rooflines and cathedral ceilings where you want to create a conditioned attic space. Superior R-value per inch and provides complete air sealing. Premium option for maximum performance.
Batt Insulation
Standard fiberglass or mineral wool batts, good for accessible attic floors with regular framing. Economical option but less effective at filling irregular cavities than blown-in.
Signs Your Attic Needs More Insulation
High energy bills compared to neighbors or to your bills from previous years.
Rooms that are too hot in summer or too cold in winter despite thermostat adjustments.
Ice dams forming on your roof in winter (sign of heat loss through attic).
Drafty rooms on upper floors or uneven temperature throughout your home.
HVAC system running constantly or cycling more frequently than normal.
Visible attic insulation less than 6 inches deep or exposed attic floor joists.
Our Attic Insulation Process
Free attic inspection and thermal assessment using infrared technology to identify problem areas.
Identify and seal all air bypasses (top plates, recessed lights, attic hatches, chases) — a critical step most contractors skip.
Address any ventilation or moisture issues to ensure long-term performance.
Install insulation to your recommended depth for optimal R-value.
Final verification and documentation of R-value achieved and compliance with DOE standards.
Attic Air Sealing — Why It Matters
Before adding insulation, Quality Waterproofing + Insulation seals all penetrations — top plates, recessed lights, attic hatches, plumbing and electrical chases, and any gaps or cracks. Without air sealing, you can add 12 inches of insulation and still feel drafts because warm air is bypassing the insulation through gaps. This is what separates a professional installation from a DIY job.
Our air sealing protocol ensures that your new insulation creates a true thermal barrier. Studies show that proper air sealing combined with insulation delivers 20-30% greater energy savings than insulation alone. We never cut corners on this foundational step.
Frequently Asked Questions
Q: How do I know if I need more attic insulation?
A: Signs include high energy bills, uneven temperatures, visible joists (less than 11 inches of insulation), and ice dams in winter. We offer free assessments to determine your exact needs.
Q: Can you insulate over existing insulation?
A: Yes, in most cases we can add blown-in insulation directly over existing insulation, saving removal costs and labor time. We'll assess whether removal is necessary based on the condition of existing materials.
Q: How long does attic insulation installation take?
A: Most residential attic insulation jobs are completed in one day, sometimes less. We work efficiently while maintaining our high quality standards.
Q: What about attic ventilation — does adding insulation affect it?
A: Proper attic ventilation is essential. We ensure soffit vents remain open and that adequate air flow continues. Blocking ventilation while adding insulation is a common mistake we watch for and prevent.
Your attic may be costing you hundreds of dollars a year.
Contact Quality Waterproofing + Insulation for a free St. Louis attic insulation assessment. We'll measure your current R-value, identify air leaks, and create a customized plan to maximize comfort and efficiency in your home.
