Quiet floors are a team sport.
In Ottawa condos, sound moves farther than most people think. A single footstep can travel through concrete, up plumbing chases, and under demising walls — straight into someone else’s movie night. That’s why boards enforce acoustic rules and why your flooring assembly must prove performance before a single plank is laid.
This guide shows condo owners and property managers what STC/IIC actually mean, how floating vs glue-down methods affect results, and the documentation Ottawa boards approve fastest.
I. STC and IIC, decoded for real-world Ottawa buildings
• STC measures airborne sound like voices and TV. Higher = better.
• IIC measures impact sound like footsteps and chairs. Higher = better.
Two details boards always ask about:
- Field vs lab Field tests (FSTC/FIIC) are usually lower than lab because real buildings have penetrations and flanking paths.
- Delta IIC (ΔIIC) Published by underlayment companies, but only meaningful when tied to a tested assembly.
Common Ottawa thresholds
Many buildings require STC 60 and IIC 60, or a proven field equivalent.
II. What actually moves the needle
• Mass below — a resilient gypsum ceiling below can add 5–10 IIC points.
• Decoupling at the floor — radiant-safe acoustic underlayments cut impact before it reaches the slab.
• Perimeter isolation — isolation strips stop sound bridges into studs and baseboards.
• Continuous detailing — undercuts, continuous underlayment, isolated transitions reduce flanking.
III. Floating vs glue-down hardwood in condo assemblies
Floating hardwood
Pros: often higher FIIC, decouples impact, easier plank replacement
Cons: can sound hollow without a dense underlay
Use when: ceiling below is hard concrete and you need max impact reduction
Glue-down hardwood
Pros: firm underfoot, excellent stability, fewer long-term noises
Cons: needs a rated acoustic membrane to meet FIIC
Use when: suite below already has a resilient ceiling or you want the most solid feel
IV. Choosing the right underlayment
A passing system balances density, resilience, and compression strength.
Best materials: high-density rubber or rubber-cork blends
Also viable: cork (with correct density), select cross-linked foams
Key metrics: ΔIIC tied to an assembly, compression set data, dynamic stiffness ratings, consistent thickness and density.
Typical Ottawa path:
A 3–5 mm high-density rubber underlay under a floating engineered floor.
For glue-down: a sound-rated membrane + full-spread elastomeric adhesive with published assembly data.
V. Documentation that condo boards actually approve
- Cover sheet + assembly diagram Slab, underlay model, flooring type, isolation method, ceiling below.
- Third-party acoustic reports Lab reports for matching assemblies and field reports if available.
- Manufacturer letters Confirming multi-residential use, and compatibility with your hardwood and adhesive.
- Installer qualifications Insurance, condo experience, supervision plan, quiet-hour compliance.
- Pre-construction checklist Flatness, moisture testing, isolation materials, transition details.
- Owner quiet-use guide Approved glides, felt pads, and runner recommendations.
VI. Field realities that derail approvals
• No perimeter isolation — baseboard nailed tight to boards = sound bridge
• Broken continuity at thresholds
• Soft underlays crushed by point loads
• Flanking through pipe penetrations
• Uneven slabs creating stiff “islands”
VII. Board-ready workflow with Royal Hardwood Floors
- Acoustic consult + rule review
- Full submittal package with drawings and test data
- Mock-up or pilot room
- Controlled installation with isolation sign-offs
- Post-install verification and photo record
Proofpoint
Royal Hardwood Floors has delivered compliant condo acoustic systems across Ottawa for over a century — from Rideau Street high-rises to Westboro boutique buildings. Approvals move faster when assemblies match tested data and installation respects isolation details.
Quick checklists
Spec Snapshot
□ STC 60 / IIC 60 (or building equivalent)
□ Floating over high-density underlay or glue-down over rated membrane
□ Perimeter isolation strip continuous
□ Isolated transitions, underlay continuous
□ Slab flatness verified, moisture tested
□ Acoustic report + manufacturer letters ready
□ Installer qualifications attached
Common Approval Package Items
□ Assembly diagram
□ ΔIIC and lab report for tested system
□ Manufacturer suitability letters
□ Install QA checklist
□ Owner care guide
FAQs
What ratings do Ottawa condos require?
Most require STC 60 and IIC 60 or field-tested equivalents.
Is floating or glue-down quieter?
Floating over dense underlay often delivers higher FIIC on bare concrete ceilings.
Can I pass without modifying the ceiling below?
Often yes — a dense underlay + proper isolation usually clears board requirements.
Does thicker underlay mean quieter?
Only if it maintains compression strength. Too soft = bottoms out = worse results.
Do boards require manufacturer letters?
Yes. They confirm multi-residential suitability and compatibility with your hardwood and adhesive.
Book A Free Quote!
Send us your building rules and a quick photo of your slab. We will recommend a passing flooring assembly and timeline.
Serving Ottawa since 1922 as the only third-generation hardwood specialist in the region.