We're in a condo in Centretown and wondering if adding thicker underlayment under vinyl helps with sound complaints.

Yes, thicker underlayment can significantly help with sound transmission in condos, but the type matters more than just thickness. Most condo noise complaints involve impact sounds (footsteps, dropped items) rather than airborne sounds, so you'll want acoustic underlayment specifically designed for sound reduction.

Standard vinyl underlayment is typically 2-3mm and provides minimal sound dampening. Acoustic underlayment ranges from 3-6mm thick and includes materials like cork, rubber, or specialized foam that actually absorb impact vibrations. Premium options like cork underlayment or rubber-backed products can reduce impact sound transmission by 15-25 decibels, which makes a noticeable difference to neighbors below.

In Ottawa condos, this is particularly important because many buildings built in the 1980s-2000s have concrete subfloors that actually amplify sound transmission. The Ontario Building Code requires sound ratings for multi-unit buildings, but older condos may not meet current standards. Your condo board may also have specific requirements for flooring installations - many require acoustic ratings of IIC 50 or higher for renovations.

For vinyl flooring specifically, look for underlayment with an IIC (Impact Insulation Class) rating of 50+ and an STC (Sound Transmission Class) rating of 50+. Cork underlayment works exceptionally well under vinyl because it's naturally antimicrobial and won't compress over time like some foam products. The investment in quality acoustic underlayment (typically $1-2 per square foot) often pays off in neighbor relations and may be required by your condo corporation.

Before proceeding, check with your property management about any acoustic requirements for flooring installations. Many Ottawa condos require notification to neighbors and may have specific product approvals. For a proper assessment of your subfloor and acoustic needs, consider getting a consultation from experienced flooring contractors who understand condo requirements.