Hear every step, jump, and dropped object from the floor above? Impact noise is one of the hardest acoustic problems to solve — but there are real solutions.
Enter your floor/ceiling assembly to see its IIC rating and find improvements.
Use IIC EstimatorThere are two types of sound that travel between floors:
Impact noise is harder to stop because it bypasses the air and vibrates the building structure directly. A wall that blocks voices perfectly can still transmit every footstep.
IIC (Impact Insulation Class) measures how well a floor-ceiling assembly reduces impact sound. Higher IIC = less footstep noise below.
Building codes typically require IIC 50 for multifamily buildings, but this is a minimum. Many people find IIC 50 inadequate for comfortable living.
Adding mass or absorption to your ceiling has limited effect on impact noise because:
Treatments on the ceiling below typically improve IIC by only 5-10 points. The real solution is treating the floor above — which you may not control.
Cork, rubber, or foam underlayment under flooring (especially under hard floors like tile or hardwood). Can add 10-20 IIC points.
A completely decoupled floor on rubber isolators. The gold standard for impact isolation — adds 15-25+ IIC points.
The simplest solution. Thick carpet with quality padding can add 20-30 IIC points. Often the most practical fix.
Drywall attached via resilient channels, not directly to joists. Adds 5-10 IIC points by breaking the vibration path.
Better decoupling than resilient channels. Can add 8-12 IIC points when combined with additional drywall mass.
Adding mineral wool in the joist bays helps somewhat but is not a complete solution. Adds 3-5 IIC points alone.
| Assembly | Typical IIC | Notes |
|---|---|---|
| Wood joist + hardwood + drywall | 30-35 | Very poor — every step heard |
| Same + resilient channels | 40-45 | Minimum acceptable |
| Same + carpet above | 50-55 | Meets code, reasonable comfort |
| Concrete slab + tile | 25-30 | Very poor without treatment |
| Concrete + underlayment + tile | 45-55 | Depends on underlayment quality |
| Floating floor system | 55-65+ | Best performance |
Enter your floor/ceiling details to see the estimated IIC and potential improvements.
Estimate Your IIC — FreeYour options are more limited, but consider: