Flooring Underlayments

Match underlayment material and thickness to your floor type and subfloor: foam or felt for laminate, cork or rubber for engineered hardwood, and specialized moisture-barrier underlayments for vinyl. Check manufacturer recommendations for required R-value, sound reduction, and whether a vapor or sound barrier is needed

Floating floors typically require underlayment to provide cushioning, moisture protection, and sound control; glued floors sometimes require a cementitious or non-compressible underlayment layer specified by the flooring manufacturer. Always follow the flooring maker’s installation guidelines to ensure warranty and performance

Underlayment materials have different impact insulation class (IIC) and sound transmission class (STC) characteristics; denser materials like rubber or thick cork provide better impact noise reduction, while foam offers moderate sound control and increased thermal comfort. Look for published IIC/STC or decibel reduction values when sound performance is a priority

For installations over concrete or in moisture-prone areas, choose underlayment with an integrated vapor barrier or add a separate vapor retarder to prevent moisture migration. Check the subfloor's moisture levels and use products rated for high humidity or slab-on-grade installations

Underlayment prices vary by material and performance, with budget options often under $50 and higher-performance sound- or moisture-resistant products in higher price tiers; category averages commonly fall around the low hundreds. Factor in coverage area (square footage) and any specialty features when estimating total cost

Many underlayments are designed for DIY installation and require basic tools: utility knife, tape measure, straightedge, seam tape, and possibly a roller for adhesive products; certain cementitious or leveling underlayments may require professional installation. Follow the product instructions for surface prep, overlap/seam treatment, and acclimation

Underlayment is generally designed to last as long as the flooring above it and requires no routine maintenance; however, moisture damage, compression, or punctures may necessitate replacement. Protect it during installation, avoid point loads from heavy appliances without proper support, and address subfloor moisture issues promptly