Part 3: Flooring Installation and Acoustics

Rules for Proper Installation

How we install is just as important as the materials e.g. acoustic underlays that are used for installation.

Fixed vs Floating Systems

Floating System

Floating systems will almost always outperform adhesive fixed floors. This is due to the separation of the flooring from the concrete substrate - and in most circumstances can provide an acceptable level of noise transfer.

A floating system is where the flooring is "floated", typically with a click lock system or glue in the tongue and groove to each other on top of an underlay. That underlay separates the floor with the subfloor.

Fixed System

A fixed system is when the flooring is glued or fixed to the subfloor or an underlayment such as plywood or underlay, or both. Fixed flooring systems are more challenging because using glue and / or nails to fix flooring facilitates noise transfer.

A fixed installation system is often where the flooring is fixed through glue (and / or nails) into the subfloor. It can also be fixed to certain rubber underlays. Note: The yellow layer denotes the layers of glue.

A fixed installation system is more complicated and we recommend contacting EVERQUIET® for personalised recommendations.

Things keep in mind:

  • Flanking noise is where sound travels indirectly around our flooring system e.g. through the walls.
  • Skirtings and beadings - sound travels through them to the walls and into the subfloor, which means its best for them to float 1mm off the floor.
  • Trims - sound travels through them into the subfloor.
  • Fixings and fixtures - particularly those that may penetrate the underlay.
  • Not all acoustic underlays can be used with all products, for example hybrid floors generally cannot use an additional underlay and most underlays compress too much and are not suitable for click install systems.
  • Not all underlays maintain their acoustic performance over time. In recent years, more thin and light foam underlays have been able to achieve better results than denser and more expensive rubber underlays, however, foam underlays tend to compress and “bottom out” much faster than denser rubber counterparts. Therefore, acoustic performance may be “short lived”, resulting in larger rectification costs in the future.

The Dilemma

Acoustic noise reduction sometimes conflicts with flooring installation best practice, two ways:

  1. Better acoustics can be worse for the floor. A less dense underlay is more flexible and softer, which generally performs better. However, a flexible underlay is generally bad for the flooring system, contributing to too much movement and especially in the case of floating floors, causes damages to the click-lock systems.
  2. Expansion trims fixed to the subfloor aren’t great for acoustics. Expansion trims are necessary for hard flooring systems, but are not great as they facilitate the direct transfer of noise.

So What Should You Do?

Get professional advice from your flooring retailer or installer, or reach out to EVERQUIET® for recommendations.

The general process is:

  1. Confirm the acoustic requirements of your body corporate i.e. acoustic star rating
  2. Choose an underlay suitable with your floor that has previously been tested with the same type of floor you are installing
  3. Confirm if the body corporate / strata committee will accept existing test reports that are indicative of performance or if they require an on-site acoustic test
When selecting underlay choose the densest and firmest underlay that meets the acoustic requirements of your body corporate, budget permitting. Firmer underlay ensures less movement in the floor and has better performance over the long run.