Flooring Underlay Guide

Renovating or building your own home can be a very big job and with many things to consider regarding flooring (colour, style, material), underlay can be the last thing on your mind.  Even though underlay is not visible after laying your floor, it is necessary to maintain the appearance and feel of your floor. 

What is Underlay? 

Underlay is the layer between the structural floor and floor covering. 

Why do you need it? 

Underlay is required for most floating floor installations where an underlay is not pre-attached (such as our Hybrids). Underlay improves the acoustic performance of your floor, provides a smooth surface enabling floating rafts to move with their climate and provide protection from subfloor moisture. 

What are the different types?  

Rubber Acoustic Underlay

Used to reduce noise levels and vibrations caused by footfall. This particular underlay is designed to absorb vibrations and assists in creating a quieter environment.  Rubber underlays can be used for both floating installations (with a plastic slip sheet) or as part of a ‘dual-bonded’ system where both the underlay and timber flooring is glued to the subfloor. 

Our 5mm and 3mm ImpactaMat underlay provide superior acoustic performance that significantly reduce foot-fall noise transmission in multi-storey buildings or multi-unit apartment buildings.   

Polyethylene 

Hush Platinum

Hush Platinum is a good quality, affordable, high density 2mm thick polyethylene underlay, suitable for use underneath most hard floating floor applications, including timber and laminate. The product comes with an integrated peel and stick design, and utilises lay flat technology, making installation quick and easy. Hush Platinum also incorporates a 0.6mm damp-proof sheet, reducing the need for a moisture barrier. Hush Platinum complies with the BCA Code on noise transmission, offering good quality acoustic performance in multi-unit apartment developments.   

Builders Plastic 

Builders plastic (200µm polyethylene membrane) is widely used in the building industry as a moisture barrier. Builders Plastic is used underneath floating floors where there is a high risk of moisture from the underneath substrate. It can be used in conjunction with the Hush Platinum Underlay to protect from subfloor moisture, or as a slip sheet when completing a floating installation over our impacta-mat rubber underlay. 

What underlay should you use? 

For moisture prone substrate floors  

Hydro-Stop Underlay 

Black Builders Plastic & Hush Platinum 

For upper floors or loud rooms  

5mm ImpactaMat

3mm ImpactaMat 

Acoustic underlay is particularly recommended in apartments, rooms with high ceilings and child/pet-friendly homes as noise and high footfall are common issues that can be resolved with underlay installation. 

Multipurpose 

Hush Platinum 

For floating installation, we recommend the use of Black Builders Plastic as a slip sheet to allow for natural raft movement. 

Shop the entire range of flooring underlay for floating floors.