Sound transmission through upstairs floors is one of the most frustrating aspects of living in a two-story home. Every footstep, chair scrape, and dropped object travels through the floor assembly and into the room below. The good news: the right flooring choice — combined with the right underlayment — can reduce impact noise by 50% or more.
Understanding the two types of sound transmission helps you make the right choice. Impact noise (footsteps, dropped objects) is transmitted through the structure itself. Airborne noise (voices, music) travels through the air and through gaps in the structure. Flooring primarily addresses impact noise — and that is where the biggest gains are made.
Understanding Sound Ratings: IIC and STC
Two ratings matter when choosing quiet flooring:
IIC — Impact Insulation Class
Measures how well a floor assembly reduces impact noise (footsteps). Higher is better. Building codes typically require IIC 50 minimum. For comfortable living, aim for IIC 60+.
STC — Sound Transmission Class
Measures how well a floor assembly blocks airborne sound (voices, music). Higher is better. Most floor assemblies achieve STC 50–60 with proper underlayment.
Quietest Flooring Options for Upstairs Bedrooms
#1 — Engineered Hardwood + Acoustic Underlayment
IIC 60–72 (with premium underlayment)Engineered hardwood's floating installation method is the key advantage. Unlike nail-down solid hardwood, a floating engineered floor sits on top of an acoustic underlayment that absorbs impact energy before it reaches the subfloor. The result is dramatically quieter footsteps. Choose a product with an attached underlayment or add a separate 8–12mm acoustic pad.
Installation Tips
- Choose 5/8" or thicker engineered hardwood for more mass
- Use a separate acoustic underlayment rated IIC 65+ for best results
- Floating installation is quieter than glue-down
- Fill any gaps at walls with acoustic sealant
#2 — LVP (SPC) + Thick Acoustic Underlayment
IIC 58–68 (with premium underlayment)SPC luxury vinyl plank is inherently denser than standard LVP, which helps with sound mass. Paired with a thick acoustic underlayment (8mm+), it achieves excellent IIC ratings. Many premium LVP products come with an attached underlayment — for upstairs bedrooms, add a separate acoustic pad on top of the attached layer for maximum performance.
Installation Tips
- Choose SPC core (denser than WPC) for better sound mass
- Add a separate 6–8mm acoustic underlayment even if product has attached pad
- Avoid glue-down installation — floating is quieter
- Use acoustic sealant at perimeter
#3 — Cork Flooring
IIC 65–75 (natural acoustic properties)Cork is nature's acoustic material. Its cellular structure — millions of tiny air-filled cells — absorbs impact energy naturally, without any additional underlayment. Cork flooring achieves some of the highest IIC ratings of any flooring product. It is also warm, comfortable underfoot, and naturally antimicrobial.
Installation Tips
- Natural acoustic performance without added underlayment
- Warm and comfortable underfoot — great for bedrooms
- Naturally antimicrobial and hypoallergenic
- Requires sealing to prevent moisture damage
#4 — Carpet (Low-Pile)
IIC 65–80 (highest of any flooring)Carpet achieves the highest IIC ratings of any flooring — but at the cost of allergen trapping and maintenance. For bedrooms where allergy concerns are minimal and maximum sound reduction is the priority, low-pile carpet over a thick pad is the quietest option. For allergy sufferers, the options above are better choices.
Installation Tips
- Highest IIC rating of any flooring type
- Use a thick (7/16"+) dense foam pad for best results
- Low-pile is easier to maintain than plush
- Not recommended for allergy sufferers
The Underlayment Is the Secret Weapon
Here is the most important thing most homeowners do not know: the underlayment contributes more to sound reduction than the flooring itself. The same engineered hardwood installed over a basic 2mm foam pad versus a premium 10mm acoustic underlayment can differ by 15–20 IIC points — the difference between clearly audible footsteps and barely perceptible ones.
| Underlayment Type | Thickness | IIC Contribution | Best For |
|---|---|---|---|
| Basic Foam | 2–3mm | +5–8 IIC | Budget installations |
| Standard Foam | 3–5mm | +8–12 IIC | Standard residential |
| Cork Underlayment | 6mm | +12–18 IIC | Good acoustic performance |
| Premium Acoustic Foam | 8–10mm | +18–25 IIC | Upstairs bedrooms |
| Mass-Loaded Vinyl (MLV) | 3–6mm | +20–30 IIC | Maximum sound blocking |
| Combination (MLV + Foam) | 10–15mm | +25–35 IIC | Best possible performance |
Frequently Asked Questions
What is the quietest flooring for upstairs bedrooms?
Engineered hardwood or LVP over a premium acoustic underlayment (8mm+) achieves IIC 65–72, making footsteps barely perceptible. Cork flooring is also excellent due to its natural acoustic properties.
How do I reduce footstep noise from upstairs floors?
The single most effective step is adding a thick acoustic underlayment (8–12mm) under the flooring. This absorbs impact energy before it reaches the subfloor. Floating installation is quieter than nail-down or glue-down. Area rugs in high-traffic zones also help significantly.
Is engineered hardwood quieter than solid hardwood upstairs?
Yes. Engineered hardwood can be installed as a floating floor over acoustic underlayment, which dramatically reduces impact noise. Solid hardwood is typically nailed directly to the subfloor, transmitting more sound.
Get Expert Advice on Quiet Flooring
Our Rochester Hills team can help you choose the right flooring and underlayment combination for maximum sound reduction in your home.