Flooring Underlayment Complete Guide 2026

Underlayment is a crucial component of flooring installation that often goes unnoticed but significantly impacts your floor's performance, comfort, and longevity. This comprehensive guide covers everything you need to know about flooring underlayment in 2026, from types and benefits to installation and selection criteria.

What is Flooring Underlayment?

Underlayment is a layer of material installed between the subfloor and your finished flooring. It serves multiple purposes including sound reduction, moisture protection, comfort, and subfloor leveling.

Benefits of Underlayment

• Sound Reduction: Reduces noise transmission between floors
• Moisture Protection: Creates barrier against moisture from subfloor
• Comfort: Adds cushioning and warmth underfoot
• Subfloor Leveling: Helps smooth minor subfloor imperfections
• Insulation: Provides thermal and sound insulation
• Extended Floor Life: Protects flooring from subfloor issues

Types of Underlayment

1. Foam Underlayment

Closed-cell foam is the most common underlayment for laminate and luxury vinyl plank.

• Thickness: 2-3mm
• Benefits: Sound reduction, moisture barrier, comfort
• Cost: $0.30-0.80 per square foot
• Best For: Laminate, LVP, floating floors

2. Cork Underlayment

Natural cork provides excellent sound absorption and is eco-friendly.

• Thickness: 3-6mm
• Benefits: Superior sound reduction, natural, moisture resistant
• Cost: $0.80-2 per square foot
• Best For: Laminate, engineered hardwood, sound-sensitive areas

3. Rubber Underlayment

Rubber underlayment offers excellent sound reduction and durability.

• Thickness: 2-5mm
• Benefits: Maximum sound reduction, durable, moisture resistant
• Cost: $0.50-1.50 per square foot
• Best For: Multi-story homes, soundproofing needs

For soundproofing details, see our Soundproof Flooring Guide.

4. Felt Underlayment

Felt provides cushioning and sound reduction for hardwood installations.

• Thickness: 3-5mm
• Benefits: Cushioning, sound reduction, traditional choice
• Cost: $0.40-1 per square foot
• Best For: Hardwood, engineered hardwood

5. Carpet Padding

Specialized padding for carpet installations provides comfort and support.

• Thickness: 1/4 to 1/2 inch
• Benefits: Comfort, sound absorption, carpet protection
• Cost: $0.50-2 per square foot
• Best For: Carpet installations

Underlayment by Flooring Type

Luxury Vinyl Plank (LVP)

Many LVP products have built-in underlayment, but additional underlayment can provide:

• Extra sound reduction
• Additional comfort
• Moisture protection (if not built-in)

See our Luxury Vinyl Plank Installation Guide for details.

Laminate Flooring

Underlayment is essential for laminate flooring to provide:

• Moisture barrier
• Sound reduction
• Comfort and cushioning

Hardwood Flooring

Underlayment for hardwood provides:

• Sound reduction
• Moisture protection
• Minor subfloor leveling

See our Hardwood Flooring Complete Guide for more information.

Moisture Barrier Underlayment

For installations over concrete or in moisture-prone areas, moisture barrier underlayment is essential:

• Prevents moisture from reaching flooring
• Required for basements and concrete subfloors
• Can be combined with sound-reducing underlayment
• See our Best Flooring for Basements Guide for basement-specific recommendations

Sound Reduction Ratings

Underlayment sound reduction is measured in IIC (Impact Insulation Class) and STC (Sound Transmission Class):

• IIC 50+: Good sound reduction
• IIC 60+: Excellent sound reduction
• IIC 70+: Superior sound reduction

For maximum soundproofing, see our Soundproof Flooring Guide.

Installation Considerations

• Subfloor must be clean, dry, and level
• Underlayment should be installed in same direction as flooring
• Seams should be taped (for moisture barriers)
• Don't overlap underlayment seams
• Follow manufacturer's recommendations

For installation guidance, see our Complete Installation Guide.

Cost Analysis

Underlayment Costs (per square foot)

• Basic Foam: $0.30-0.50
• Premium Foam: $0.50-0.80
• Cork: $0.80-2
• Rubber: $0.50-1.50
• Felt: $0.40-1

2026 Underlayment Trends

• Eco-Friendly Options: Recycled and sustainable materials
• Combined Functions: Moisture barrier + sound reduction in one
• Thinner Profiles: Maximum performance in minimal thickness
• Radiant Heat Compatible: Underlayment designed for radiant heating

Frequently Asked Questions

Do I need underlayment if my flooring has built-in padding?

Additional underlayment can still provide benefits like extra sound reduction or moisture protection, but check manufacturer recommendations.

Can I use the same underlayment for all flooring types?

No, different flooring types have different underlayment requirements. Always follow manufacturer specifications.

How thick should underlayment be?

Thickness varies by type: foam (2-3mm), cork (3-6mm), felt (3-5mm). Follow manufacturer recommendations for your flooring.

Is underlayment required?

For most floating floors (laminate, some LVP), underlayment is essential. For nail-down or glue-down installations, it's often optional but recommended.