NYC Hardwood Flooring — Sound Rating, Co-op 80% Rule, Refinish vs Replace
NYC hardwood flooring reality. Co-op 80% area carpet rule enforced via Alteration Agreement, STC 50 assembly requirement for new floors, refinish vs replace economics, water-based vs oil-based finish. $8K-$45K typical.
Most NYC co-op Alteration Agreements require 80% of finished floor area to be covered with sound-absorbing material. The rule exists to protect the downstairs unit from impact sound. New hardwood floors in a co-op typically need an STC 50 assembly — cork or mass-loaded underlayment beneath the hardwood — to pass managing-agent review.
Frequently asked questions
What is the NYC co-op 80% rule? Most co-op Alteration Agreements require 80% of the finished floor area to be covered in sound-absorbing material (rug, cork, carpet). Hardwood floors typically need an underlayment that meets STC 50 to satisfy this clause.
Refinish or replace NYC hardwood? If the existing floor has at least 2-3 mm of wear layer remaining, refinish. Replace when boards are damaged beyond sanding or when you're changing species or stain direction.
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