Sound control in the flooring industry is a thankless job. Think about it, if the product is installed and functions properly the end user never even knows it’s there. No concerns, no complaints and, most unfortunately, no pats on the back.
This is exactly the reason why in the noise reduction industry no news is certainly good news.
To understand how noise is controlled in the floor/ceiling assembly we first have to understand just what noise is. Floors are inherently more difficult to reduce noise issues mostly because there are two completely separate factors to be concerned with—airborne noise and impact noise.
An example of airborne noise is the sounds we make from speech, whereas impact noise is the thudding of a stomp.
It’s important to understand the two different types because they are controlled in two entirely different ways.
Airborne noise is primarily controlled by the mass of the assembly. So essentially the heavier the products used in the floor/ceiling the more effective they will be in limiting the ability for sound to travel through. An easy example of this would be the difference between a wood frame project and one built out of thick concrete slabs. The concrete has much more mass than the wood does so the sound will not pass through the assembly in an efficient manner.
Impact noise, on the other hand, is best controlled by isolating one part of the assembly from another member of that assembly. Vibrations travel through connections, so the best way to filter out a vibration is to create a disconnection so there is no efficient path for which to travel.
No Quick Fix
So now the first question is, which one is your biggest concern: Airborne noise or impact noise? Unfortunately, there is no quick fix to address both issues as most products either focus on addressing just one of the types of noises. Understanding, or anticipating, which type of issue might be the biggest area of concern is a key first step in product selection.
Your second question should be: What type of construction am I working on? The best solution for new construction projects quite commonly is not the same for renovation projects. With new construction you get an opportunity to adjust initial plans and specifications so your sound control systems are built right into the flooring assembly. With renovation projects the best option is typically one that is the least invasive.
So let’s separate the two, new build vs. renovation, and discuss which product might be the best choices.
In new construction projects we do not have to worry about removing layers from the floor/ceiling assembly to sound deadening products because we can just do it right from the start.
Multifamily projects all across the county are becoming more aware of the headaches a noise issue complaint can cause and are taking this proactive approach. One of the most common standards to suppress both airborne (STC) and impact (IIC) noises is the use of a self-leveling cementitious topping slab installed over an acoustical mat product.
One such product being the Quiet Qurl branded entangled nets provided by Keene Building Products, which are an entangled net sound mat that is loosely laid over the subfloor specifically designed for a concrete topping to encapsulate the product.
The genius in this sandwich of products is its simplicity. The entangled net decouples the concrete topping slab from the subfloor below essentially creating a floating floor system. This makes it much more difficult for vibration to pass through the floor and into the ceiling, resulting in a system that can limit the impact noise that is heard below (think footfall noise).
The concrete topping slab, typically a gypsum concrete product, gives the assembly the mass it needs to slow down the airborne noise from traveling through, all while providing a flat and sturdy base for a variety of floor coverings.
When it comes to renovation projects, typically we just do not have the capability to rip down the ceiling or get a contractor to come in and pour some concrete.
The options need to be much less invasive and not critically alter the dimensions of the floor height, which quickly cause a domino effect on other portions of the room. In these scenarios you typically see the addition of what is referred to as a “topically added” sound mat. These products consist of many different make-ups ranging from thin fabrics, cork, foam and plastic veneers. Keene markets a product, QQ Step Soft, which is a sound mat made up of rebonded recycled rubber shreds. Resembling a gymnasium flooring, QQ Step Soft acts as a cushion for impact noise to be absorbed in the floor/ceiling assembly.
When installed underneath tile, laminates, vinyl and engineered wood products QQ Step Soft can greatly reduce the amount of footfall noise experienced by the party below.
For airborne noise issues, since adding a significant amount of mass to the assembly is typically not an option, renovators have two viable options. Unfortunately both require access to the ceiling side of the assembly, which in multifamily applications can be troublesome. If access is available, two viable options are adding insulation into the cavity and adding an additional layer of drywall board to the ceiling. Both options should provide a measurable increase to the floor’s airborne noise dampening ability.
Noise control is and will continue to be one of the hot topics in the construction industry. As people continue to squeeze into dense population centers, we are going to continue to build up to accommodate them. The good news is technology and good building practices are allowing our floor/ceiling assemblies to keep up with this trend. This makes providing a comfortable, private and quiet living space much more obtainable for our future tenants—even if we don’t get thanked while doing so.
Sounds good doesn’t it?