Crumb Rubber Underlayment

 Acoustical underlayments are used to prevent impact sounds from transferring from the floor above to the room below.  They act as a decoupling layer between the hard surface of the building and the flooring being installed on top.  Underlayments are crucial components when the flooring installed is a hard surface product. 

If a hard surface product is adhered directly to the building, impact (mechanical) sound transfers directly through both hard surfaces easily.  The two materials act like a single hard surface.  An underlayment decouples the two hard surface materials, and breaks the movement of the sound wave through the flooring and the subfloor.
 
There are a variety of materials used as underlayment.  Underlayments can be attached to the flooring.  This is an integrated underlayment.  They can also be separate, and the flooring is installed on top of the underlayment.  All of the materials work in much the same way providing a break between the hard surface floor and the building.  The common materials used as underlayment are:

• Foam

• Cork

• Felt (Fabrics)

• Crumb Rubber

 
All of the underlayments are effective in greatly improving Impact Noise performance (IIC).  For the purpose of this document we are addressing only the last one, crumb rubber and it’s uses under hard surface flooring. 
 
Crumb rubber is produced from recycled car tires.  These old tires are ground up, heated, and pressed into a solid form.  The solid forms are then peeled off into rolls of various thicknesses based on the end use.  The process is similar to how wood veneers are peeled / sawn from a log.  You end up with a dense roll of high recycled content underlayment. It is commonly used as an acoustic underlayment and in sports floor applications.
 
Shaw Industries warranty does not provide coverage when our flooring is installed on crumb rubber underlayment for the following reasons:
 

1. Crumb Rubber is made from Car Tires which are produced from Styrene Butadiene Rubber (SBR).  Adhesives used to adhere to SBR are styrene based adhesives.  Styrene adhesives are not compatible with vinyl flooring.  They can lead to performance and stability issues.

2. When SBR comes in contact with vinyl flooring, performance issues can occur similar to the adhesive issue.  The end result is often resilient flooring having stability and performance issues.  An additional frustration for a customer is to have an issue and have multiple suppliers blaming each other for the issue.  The end user is stuck and no one is resolving the issue. 

3. Shaw has experienced the click and lock mechanism failing when installed on crumb rubber.  Shaw has underlayments that we supply and performance tests that do not have this issue.  They are typically thin and do not compress. 

4. Crumb rubber underlayments are dense and heavier than foam, cork, and fabrics.  They are much more difficult to handle than other underlayments.

For these reasons Shaw feels there are product underlayment options that do not have performance issues and offer easier handling and installation.  We are able to supply a range of underlayment options that we feel are more appropriate for housing applications.