Flooring Acoustics in Canada: STC, ASTC and IIC
For apartments and other noise-sensitive projects, start with the building assembly and the project acoustic requirement. A number printed beside a flooring sample is not enough to assess the installed result.
Three ratings, three different questions
| Metric | What it describes | What to request |
|---|---|---|
| STC | Airborne sound insulation of the tested separating element. | Wall or floor assembly details and the airborne sound test report. |
| ASTC | Apparent airborne sound insulation, including direct and flanking transmission paths. | Project junction details and the assessment or field result relevant to those paths. |
| IIC | Impact sound insulation under the conditions of the reported test. | Complete floor/ceiling assembly, substrate, pad, installation method and test method. |
Read the assembly before the headline number
Slab or timber floor
Record slab thickness or the timber floor build-up. A result over concrete does not establish performance over a lightweight timber system.
Suspension and insulation
A suspended ceiling, cavity and insulation can contribute substantially to the result. They must stay visible in the report summary.
Flooring and backing
Identify the SKU, attached or separate underlay, adhesive or floating installation and perimeter details. Do not add a second pad without installation approval.
Use the project requirement as the acceptance basis
The National Building Code is a model code; the applicable provincial or territorial adoption and the project specification determine the requirement. A condominium or developer may also impose its own flooring rules.
- Get the acoustic briefAsk for the required metric, threshold, test method and whether a laboratory report, field measurement or design assessment is required.
- Match the proposed assemblyCompare the report against the slab or timber floor, ceiling, underlay and installation details of the project.
- Agree the evidence routeGive the designer or acoustic consultant the complete report before purchase. Include any required on-site testing in the project plan.
What to send Ecoflors
Send the project province, room use, base-floor construction, ceiling details, required metric and threshold, proposed floor type and the tender wording. For SPC, include board thickness and backing; for Loose Lay or Dryback, include the proposed fixing method.
Acoustic procurement questions
Does an IXPE pad guarantee an IIC result?
No. Pad material and thickness do not establish the acoustic rating of the building assembly. Read the complete test build-up and method.
Can a laboratory IIC rating guarantee the field result?
No. Site junctions, workmanship and transmission paths can differ. Use the project’s specified field acceptance procedure where one is required.
Is ASTC a flooring-only rating?
No. ASTC includes the separating element and sound transmitted through connected elements. Flooring selection is only one part of that assessment.
Should the highest advertised number decide the order?
Compare reports on equivalent assemblies first. A higher figure obtained with a different ceiling or substrate may not describe a better flooring product for your project.
Related buyer resources
Sources and further reading
Send the build and destination
Tell us the construction, wear layer, size, quantity per colour, destination and required documents. This gives the quotation a clear product and delivery basis.