Essential Home Soundproofing Tips for Contractors
In residential homes, condos and multi-family apartments, protecting occupants from recurring, excessive noise has become a growing and increasingly important part of the renovation business. By doing so, contractors can not only generate more revenue but also literally improve the quality of life of appreciative homeowners or tenants.
Noise can come from both exterior and interior sources. Locations near busy streets must suffer vehicle traffic, sirens, alarms, squealing tires and brakes, not to mention passing trains and airplanes. Neighbors that share a common wall often must endure loud, thumping loud music, barking dogs and loud conversations.
For those homeowners prepping a basement or room for full-time rental to a family, possibly with pets, engaging in some basic soundproofing remodeling makes perfect sense for everyone’s piece-of-mind.
“The current building code do not require structures to be soundproofed anywhere near the level that homeowners prefer,” says Randy Brown, President of Soundproof Windows, Inc., a national soundproofing expert and manufacturer of window and patio door soundproofing products. “That opens the door for contractors to offer proven soundproofing solutions that can really quiet things down for the homeowner.”
Brown adds that for many contractors, the field of soundproofing can seem confusing. After all, the science of acoustics can seem complicated. Exacerbating matters, contractors tend to get information through word-of-mouth and internet sources where there can be conflicting information.
“Contractors generally learn by word of mouth from other contractors, so bad information can stay around a long time and just gets repeated,” says Brown.
Fortunately, by following a few proven tips in this regard, and by consulting with soundproofing experts, contractors can expand their business opportunities and create loyal, repeat customers for future jobs.
Multiple studies have shown that 90 percent of exterior noise enters through windows. Unfortunately, simply replacing the windows with double-pane windows seldom adequately resolves the problem.
“With double pane windows, the two pieces of glass within the frame vibrate like the two tynes of a tuning fork which actually creates more noise,” explains Brown. “The air space for both double and triple pane windows also does very little to retard sound vibrations.”
Brown adds that much of the noise that enters through windows comes through leaking window seals. With age conventional window seals fail, so any partial relief experienced by replacing windows may be short-lived.
To gain an edge over rivals, some contractors and homeowners are turning to true soundproofing companies like Soundproof Windows, Inc. that have expertise engineering products used in the most noise sensitive environments in the world, like recording studios.
The company has created a “second window” that can be installed easily in front of the existing windows. The product is designed specifically to match and function like the original window, no matter its design or whether it opens or closes.
This inner window reduces noise from entering on three fronts: the type of materials used to make the pane, the ideal air space between original window and insert, and finally improved, long-lasting seals. The combination can reduce external noise by up to 95%.
“The first noise barrier is laminated glass, which dampens sound vibration much like a finger on a wine glass stops it from ringing when struck,” explains Brown. “An inner PVB layer of plastic further dampens sound vibrations.”
Air space of 2-4 inches between the existing window and the Soundproof Window also significantly improves noise reduction because it isolates the window frame from external sound vibrations.
Finally, the company places spring-loaded seals in the second window frame. “This puts a constant squeeze on the glass panels, which prevents sound leaks and helps to stop noise from vibrating through the glass,” explains Brown.
When choosing soundproofed windows, Brown adds that the most objective measure of sound reduction is the window’s Sound Transmission Class (STC) rating. In this rating system, the higher the number the more noise is stopped. A typical rating for standard windows is 26 to 28, for example. The acoustic soundproof windows, by comparison, earn a 48 to 54 STC rating.
Since external noise can also enter regular doors as well as sliding glass patio doors, similar soundproofing strategies can also be effectively applied in these applications.
To stop noise coming through entry doors, checking and or replacing the seals is important. Beyond that, adding a glass storm door that seals well can help. This will usually raise the door to the same or better sound stoppage level as the walls.
In terms of sliding doors, like the soundproof windows, a second sliding glass door can be added, but mounted either inside or outside an existing sliding glass door, according to Brown. This can eliminate up to 95% of external noise entering through the patio door.
An added benefit of this approach is how it can help to eliminate draftiness and improve energy efficiency in sliding glass doors as well. The room with the sliding glass door is usually the home’s coldest and draftiest room. The large glass area and poor seals are usually the reason. By adding a second sliding glass door, draftiness is virtually eliminated, which significantly improves both home comfort and energy savings.
“To reduce sound intrusion through walls, the place to start is adding traditional 5/8” sheet drywall to existing walls,” says Ted White, President of Soundproofing Company Inc., a specialist in noise intrusion in walls, ceilings, and other building structures.
According to White, this adds mass to the walls and acts as a barrier, which helps to limit sound vibration through the walls. He cautions, against using newer 1/2” drywall, however, because changes to the substrate designed to lighten the weight and reduce the amount of gypsum used actually makes the product even less soundproof than it was prior.
If further noise reduction is needed, White suggests removing the existing drywall and installing clip and channel systems to the wall framing. This enables separation between the drywall and studs, and stops much of the sound vibration and transfer through the wall.
Adding insulation within the wall cavity can also enable some sound absorption within the wall, says White. However, he warns that the insulation should never be compressed or packed tightly. That would defeat the purpose of separating the materials, and encourage sound vibration through the studs and insulation.
To further dampen sound vibrations through the walls, White recommends adding a material like Green Glue between layers of drywall. The material, he says, can absorb vibration more cost effectively than other materials.
In terms of stopping ceiling noise in areas like basement conversions or rentals, the first consideration is usually pipe noise, according to White.
“Waste water may drop two stories before crashing into the final pipe angle in the basement, which can generate a lot of noise,” says White. He notes that the culprit in this case is usually that the pipe has been jammed into a hole up against the stud. This conducts pipe vibration through the drywall, which then acts “like a speaker to broadcast” the noise.
In such cases, White notes that the noise can be significantly reduced by slightly increasing the size of the piping hole so it no longer touches the stud, and wedging in a small piece of foam. This absorbs sound vibration so it is not conducted to the drywall.
He also suggests that adding loose insulation can aid sound vibration absorption.
In regards to ceiling lighting, White recommends installing smaller, 4” diameter “can” lights rather than larger recessed lighting products up to 8”. The smaller the holes cut in the ceiling drywall allow, the less sound – particularly the lower frequency sounds – will come through the ceiling.
While soundproofing techniques may be unfamiliar to many contractors, industry experts believe that remodeling efforts aimed at addressing noise issues will continue to gain traction with more and more people living in tighter, more condensed living spaces.
“At some point, soundproofing should become a line item right along with plumbing, electrical, windows and floor treatments,” concludes Soundproof Windows’ Brown. “These things are infinitely easier to put in if they are planned up front. Contractors who can guide homeowners through the process, and work with expert partners, will have an edge in the market.”