Carpet hides footsteps. Laminate and vinyl plank do not, and in a condo the person who hears that is your downstairs neighbor. That is why many Seattle and Eastside associations write rules about hard flooring in upper units, from a sound rating to board approval to an outright ban in bedrooms. This guide walks you through finding your building's rules, understanding the numbers in them and getting a yes in writing before you order a single box.
Why condo floors come with rules
Washington condominiums run on their governing documents: the declaration recorded when the building was created, the bylaws, and the rules and regulations the board adopts under them. Older buildings fall under the state Condominium Act (RCW 64.34) or the earlier Horizontal Property Regimes Act, and newer communities under the Washington Uniform Common Interest Ownership Act (RCW 64.90). Whichever applies, the floor in your unit usually sits on structure the association maintains, and noise between units is exactly the kind of thing boards regulate.
Seattle's condo stock makes the issue sharper. A Capitol Hill or Queen Anne conversion may be a wood-framed apartment building from the middle of the last century, where impact noise travels easily through joists. A Belltown, South Lake Union or downtown Bellevue tower has concrete slabs, which block airborne sound well but still carry the click of heels and dropped objects. The same plank behaves differently over each, and good rules account for that.
How to find out what your building allows
You do not need a lawyer for this, just patience with the paperwork.
- Get the documents. Ask the property manager or board secretary for the current declaration, bylaws and rules and regulations, plus any flooring or alteration policy adopted separately. Ask whether anything has been amended recently.
- Search for the right words. Look for "floor", "flooring", "hard surface", "sound", "acoustic", "IIC", "STC", "underlayment", "alteration" and "architectural review". Flooring rules often sit under alterations to units rather than under noise.
- Write down every requirement. Note any minimum rating, any required underlayment, rooms where hard floors are or are not allowed, a required area-rug coverage, permitted work hours, and whether the board must approve before work starts.
- Ask the manager what the board actually wants to see. Many boards have a short application: product name, underlayment name, the manufacturer's sound test report, the installer's registration and insurance, and the dates.
- Check for older flooring under the carpet. In buildings from before 1980, old vinyl tile or black mastic may sit under the carpet and can contain asbestos. Do not scrape or sand it. Puget Sound Clean Air Agency rules generally require an asbestos survey before renovation that disturbs building materials; check the agency's site for what applies to your unit.
- Pick the product and underlayment to fit the rule, not the other way round. Then submit the application and wait for approval in writing.
- Book the elevator and work hours. Once approved, reserve the elevator or loading area and confirm noisy work fits the building's permitted hours.
Reading the sound numbers
Two ratings show up in condo rules and on underlayment spec sheets.
IIC, Impact Insulation Class, measures how well the floor-ceiling assembly reduces impact noise: footsteps, dropped keys, chair legs. This is the one that matters most for hard floors.
STC, Sound Transmission Class, measures airborne sound such as voices and television. Flooring and underlayment change it far less than IIC.
Both are measured on a whole assembly. A lab test reports the result for one specific build-up, for example a given concrete slab thickness, with or without a suspended ceiling, plus the underlayment and the flooring. Some manufacturers also publish a Delta IIC, the improvement the underlayment adds over a bare slab. A field test, sometimes written FIIC or similar, is measured in a real building after installation and usually comes out lower than a lab number, because real buildings have flanking paths and imperfect ceilings.
The building codes Washington adopts set 50 as the lab-tested minimum for both ratings between dwelling units in new construction, or 45 when field tested. If your rules name a number, check which test it refers to. A report for a 6-inch concrete slab with a drywall ceiling below says little about a wood-framed 1960s building, so ask the manufacturer for a report that matches your structure.
Choosing a floor and underlayment that pass
- Start with the underlayment. In upper units, the acoustic underlayment does most of the work. Dense rubber, cork and high-density foam products are sold for condos with test reports; thin foam often is not enough.
- Check the flooring manufacturer's instructions. Many rigid-core vinyl planks with an attached pad do not allow a second pad underneath, or only allow specific ones, and adding the wrong one can void the warranty and make joints flex. If you need more sound control than the attached pad gives, a plank without a pad over an approved underlayment may be the better path. The vinyl plank installation and laminate installation pages explain the product differences.
- Keep the perimeter isolated. Flooring that touches walls, cabinets or pipes passes impact sound around the underlayment. A floating floor needs its expansion gap anyway; keep it clear and leave the trim off the floor surface.
- Mind the height. Thicker underlayment raises the floor. Check door clearances, the dishwasher, the balcony slider threshold and transitions to tile in the bathroom. Our guide to installing over existing floors covers height in more detail.
- Glue-down is a separate question. Some boards approve glue-down vinyl over an acoustic mat; others do not. Do not assume one approval covers both methods.
What it costs
These are typical Seattle-area ranges for planning. They vary by building, product and condition, and your written quote is the real number.
| Item | Typical range | Notes |
|---|---|---|
| Acoustic underlayment, material | About $0.75 to $2.50 per sq ft | Rubber and cork toward the top |
| Rigid-core vinyl plank, installed | About $6 to $12 per sq ft | Includes standard labor and product |
| Laminate, installed | About $5 to $9 per sq ft | AC4 lines, normal prep |
| Carpet and pad removal | About $1 to $2 per sq ft | Tack strip and staples included |
| Asbestos survey of suspect materials | Varies | Priced by the inspector and number of samples |
| Field sound test, if required | Varies | Quoted by the acoustical tester |
The rules can add cost in quieter ways: elevator reservation fees, a deposit for common-area protection, or work limited to certain hours, which can stretch a job over an extra day. Ask the manager about any building fees when you ask for the documents.
When to call a professional
You can read the documents and gather spec sheets yourself. Bring in an installer when:
- The rules name a specific IIC or FIIC number and you are not sure which product combination meets it over your building's structure.
- Lifting a carpet corner shows old vinyl tile, sheet vinyl or black adhesive in a building from before 1980. Leave it in place and get it tested.
- The concrete slab or wood subfloor is visibly uneven, cracked or stained from past leaks. See old floor removal and subfloor prep.
- The board wants the installer's Washington L&I registration, insurance certificate and product documents on the application.
- You are doing several units or a rental condo; the rental and multi-unit flooring page covers per-unit quoting and sound documentation.
An installer who works in Seattle and Eastside buildings will ask for your association's requirements at the measure and specify a product and underlayment combination with the paperwork the board expects. Doing it in that order is far cheaper than pulling up a floor after a neighbor's complaint.
