When do you need code compliance documentation?
When two or more separate residential occupancies are physically connected with common floor/ceiling junctions or common wall junctions, G6 (soundproofing) building code requirements apply.
This means that inter-tenancy walls have to be designed to achieve sound transmission class (STC) 55 or higher and/or test to STC 50 or higher on-site.
Inter-tenancy floor/ceiling building elements have to be designed to achieve impact insulation class (IIC) 55 and/or test to IIC 50 or higher on-site, as well as achieve vertical STC 55 design/vertical STC 50 on-site.
This needs to be demonstrated as satisfactory to council’s building inspectors before your building’s code compliance certificate (CCC) can be issued.
How is acoustic testing and certification carried out?
When I’m asked to certify G6 building code compliance, I will attend the site with my test gear and test the building’s soundproofing. If the building’s soundproofing is fine, I will certify it as compliant to G6 of the New Zealand Building Code.
I have been doing this type of work since 2004 (I was Auckland Council’s sole specialist building soundproofing inspector for 12 years) and have personally performed over 10,000 on-site building soundproofing tests.
When I attend a site, I will use either my specialist STC (loudspeaker) test rig or my specialist (IIC) floor tapper test rig.
I will make some noise either next door or upstairs, using either my specialist loudspeaker or my floor tapper, then measure in the adjacent or downstairs unit(s) using a specialist sound meter.
If your new building’s soundproofing is compliant, I will certify it. I can turn paperwork around in 4 hours – if you are in a hurry – and I am usually in Hamilton 2 days/week. If you are in a jam, try me, I can sometimes respond to your site quickly.
IIC tests
This is my floor tapper (shown to the left). It drops small weights onto the floor surfaces, creating structure-borne vibration. Having one of these enables me to go downstairs and measure how soundproof a floor/ceiling assembly is regarding footstep noise.
STC tests
This is my loudspeaker test rig. It broadcasts broad-spectrum (pink) noise uniformly and loudly around a room, enabling me to go into the tenancy next door and measure how soundproof an inter-tenancy wall is.
