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This is Part 1 Of A 2-Part Article Discusses Ways To Reduce Outdoor Noise Entering Your Home.  The article is written for those seeking ways to reduce outside noise from entering their current home.  These are modest to moderate cost upgrades.   Additionally, this information is appropriate for a new home being built 

Al’s Plumbing, Heating & A/C in Plano, Texas provides maintenance & repairs for all brands of Central A/C, Gas & Electric Furnace, and Heat Pumps.  Additionally, we sell and install new HVAC Systems from American Standard (same company as Trane), Ameristar (same company as American Standard) and Coleman HVAC (same company as York HVAC).

Al’s also provides full-service plumbing maintenance, repairs, and replacements for every plumbing component in your home.  Al’s sells and installs Rheem Professional Series gas & electric water heaters, and tankless water heaters.  Al’s is near your home in; Richardson, TX; Garland, TX, and northeastern Dallas, TX.  We service all homes in northern Dallas County, TX; northern Tarrant County, TX; and southern Collin and Denton Counties with no additional travel charge.  Call Al’s today to discuss any concerns or problems you have with your HVAC System or Plumbing.  We will arrange an appointment at your convenience.

Click Here For Part 2 Of Our Article: Reduce Outside Noise – Part 2

Ways To Reduce The Volume Of Outdoor Noise Entering Your Home

Within This 2-Part Article — We’ll Go Into Detail About The Best Ways To Reduce Outside Noise Entering Your Home

Considering Both Volume & Frequency.

What Is Sound?

  • Sound is the energy created when things vibrate.
  • Sound is vibrations of atoms or molecules — and the orderly movement of these molecules through the air at 1,075 feet per second.
  • As sound travels — it generates a tiny amount of heat.
  • Once sound-waves energy reaches the ears — the sound can be heard.
  • Humans hear sounds between about 20 Hertz (Hz) — (boomy sounds like thunder) up to 20 KillowHertz (kHz) — (high-pitched sounds like chirping birds).
  • To stop sound — it must be completely transformed (from sound-waves energy) into (a tiny amount of) heat. 
  • For this to occur, the orderly movement of the molecules through the air must be disrupted — and become disorderly.
  • The disorderly movement of molecules then becomes heat.
  • Sound vibrations converted to heat reduce or eliminate the sound’s volume.

Common Noise Volume Levels — In Decibels / dB:

 30 Whispered voice

 60 Normal conversation

70  Freeway traffic — from 50 feet away *3   Click Hre To Hear Highway Traffic At A Short Distance (at Time :30 / 1:40): Highway Traffic At A Short Distance.

76  A Boeing 737 jet taking off — from 1 mile away.    B-737 is the most common aircraft used in the U.S. today.  Click Here To Hear A B-737 Taking Off (at Time 4:50 / 14:17): B-373 At Take Off

 90 Lawnmower

110 Chain saw

120 Ambulance & Fire Truck siren

*3 Source: https://www.codot.gov/projects/i-70-old-mountaincorridor/final-peis/final-peis-documents/technical-reports/Vol4_I-70_Mntn_Corridor_Final_PEIS_Noise_TR.pdf

Sound Transmission Class / STC

Sound Transmission Class (STC) — represents how well a material blocks noise-transmission between spaces.  To reduce outdoor noise entering your home — higher STC numbers represent the sound volume reduction in decibels (dB).  -3 db decrease in volume is barely perceived by a typical listener.  A -10 dB is perceived as half the volume.   STC Rating helps you determine the merit of a noise-reducing material.  A product with only a marginally better STC Rating is seldom worth the extra cost.

Example-1: From A Noise-Reduction Standpoint — The Additional Cost Of Fiber-Cement Siding (STC:39) Versus Vinyl Siding (STC:35) Is Not Justified.

STC Examples:

  • STC: 60 Excellent Sound Control
  • STC: 50 Loud Speach Can’t Be Heard
  • STC: 45 Loud Speech Is Difficult To Hear
  • STC: 40 Loud Speech Can Barely Be Heard
  • STC: 35 Loud Speech Can Be Heard — But You Can’t Make Out What’s Being Said.
  • STC: 30 Loud Speech Can Be Heard & Understood.
  • STC: 25 Normal Volume Speech Can Be Heard & Understood.

 

  • STC: 55  Brick, insulated exterior wall.
  • STC: 45 Stucco, insulated exterior wall.
  • STC: 39 Fiber-cement siding, insulated exterior wall.
  • STC: 35  Vinyl siding, insulated exterior wall.

If You Hear Outdoor Noise Inside Your Home — It’s Most Likely Location Is Through The Ceilings (details below).

 

To effectively reduce outdoor noise inside your home — you need to understanding which High-STC materials are right for your home. 

The best materials depends on the type of noise you’re hearing (Example: aircraft versus highway traffic). 

You May Wonder Why The Type Of Noise You’re Hearing Is Important. 

Example:

  • Most aircraft Noise Frequency is very low (under 200 Hertz (Hz).  Frequency represents how boomy the noise is. 
  • A Boeing 737 jet taking off (from 1 mile away) is 76 decibels (dB),  Decibels represent the volume of the noise.  
  • Aircraft noise sounds very boomy.   
  • Thunder is 20-120 Hertz (Hz).
  • Most highway traffic Noise Frequency is somewhat high (around 1,000 hertz). 
  • Highway traffic (from 50 feet) is 70 decibels (dB),  
  • Traffic noise does not sound boomy. 
  • Chirping Birds are 1000+ Hertz (Hz).

 

 

 

Example-2: From A Noise-Reduction Standpoint — The Additional Cost Of Nearly Doubling Attic Insulation Depth From 11 Inches (STC: 24.5) To 24 Inches (STC: 50.5)  — Is Well Worth The Cost.

Each -10 dB Reduction Is Perceived As Reducing The Volume By Half

 

STC: 24.5  Ceiling with 11″ (R-38) blown fiberglass Attic Insulation (STC-Insulation = 22 + STC-Drywall = 2.5).  Note: R-38 / 11″ is required in DFW by Texas Building Code.

STC: 50.5  Ceiling with 24″ (R-86)  blown fiberglass Attic Insulation (STC-Insulation = 48  +  STC-Drywall = 2.5 ).  Details Below.

STC: 60+ is considered excellent sound control.  This does not mean the space is soundproof — only that little noise will transfer to into or outside the space.

 

As Compared –Noise Reduction Coefficient / NRC

Noise Reduction Coefficient (NRC) represents how well a material absorbs noise generated within a space.  The NRC number represents the percentage of noise (directly hitting the material) that will be absorbed.  NRC ratings are .0 (0%) — 1.0 (100%).  NOTE: If the noise does not directly hit the NRC-Rated object (perhaps the object is behind the source of noise) — less or no noise will be absorbed.

Example Of Noise Directly Hitting An Object — Versus Noise Directed Away From An Object: Outdoor Rotating Tornado Sirens are designed to project sound a long distance.  The siren is louder while it’s pointed directly at you — and quieter while pointed away.

 

Click on the arrow in the center of the photo below to hear this effect.

 

NRC Examples: **

NRC: Up to .75 (75%) Typical ceiling tiles.

NRC: .8 (80%) Hi-Performance ceiling tiles.

NRC: .7  (70%) Cork wall tiles — 1 inch thick

NRC: .05 Drywall

NRC: .05 Glass

NRC: .00 Marble

 

NRC: .6 Fabric Chair

NRC:.05-15 Lightweight draperies

NRC: .6 Heavyweight draperies

NRC: .55  Heavy carpet on foam-rubber pad over concrete floor.

NRC:. 30  Heavy carpet (no pad) over concrete floor.

NRC: .05  Vinyl floor over concrete floor.

NRC: .05–15 Wood over concrete floor.

NRC: .35 Unpainted concrete block. (65% of the noise hitting the block is reflected back into the room).

NRC: .05 Painted concrete block.  Painting the block causes it to reflect more noise than unpainted.

 

From The Numbers Above — To Best Materials To Reduce The Volume Of Noise Generated Within A Room:

  • 1-inch thick cork wall tiles — to absorb 70% (NRC .7) of the noise hitting the walls.
  • Typical ceiling tiles — to absorb 70% (NRC: .7) hitting the ceiling.
  • Thick carpet over a rubber carpet-pad — to absorb 55% (NRC: .55) of noise hitting the floor.

** Source: http://www.nrcratings.com/nrc.html

** Source: https://svetlanaroit.files.wordpress.com/2009/11/visual_values2.pdf

 

STC Ratings Of Common Building Materials

photo of home windows from outside

Image Source: ShutterStock

Below is a guide to which building materials work best to reduce outdoor noise entering your home.  Again, the best building materials depends on the type of outdoor noise you’re hearing — such as aircraft versus traffic noise.

WINDOWS:  STC: 27–50+

  • STC: 27  Single-Pane Glass
  • STC: 30 Common Double-Pane Glass
  • STC: Up to 40 Laminated Glass **
  • STC:45-50  Both laminated & double-glazed glass in the same window. **
  • STC: 50+ Moonray’s DeVAC 600 Series Aluminum Replacement Windows.
  • STC: +25: Add Storm Windows.
  • STC: +29-33:  Add Noise-Reducing Storm Windows.

NOTE: For Total STC when storm windows are added — add existing window STC + Storm Window STC.

** Source: https://www.dillmeierglass.com/news/stc-ratings-of-glass

 

These 4 Factors Will Increase A Window’s STC Rating:

  • Amount Of Air-Space Between Glass Panes.  The wider the space, the more sound-reduction ability.  This is why adding a storm window produces a higher STC than a replacement window (without storm window).
  • Glass Thickness
  • If a window has two panes of glass — and the panes are different thicknesses (a common feature in noise-reducing windows).  Different thickness of glass block different sound frequencies — providing increased noise reduction. **
  • If Laminated Glass Is Used.  Laminated glass has 2 or more glass panes — with a layer of plastic or vinyl between the panes.  This will be the most expensive option.
  • Laminated glass can add 15% — 80% to the windows’ cost. **

NOTE:

  • Check the STC ratings of each window or storm window you’re considering.  There’s no benefit in spending more money for a window with only a marginally higher STC rating.
  • STC of 3 or less is not that perceivable by most listeners.  If a reduced of STC: -10 is perceived as half the noise — the cost difference for a higher STC rating of 4 or less is likely not justified.
  • +/- 3 STC change is barely perceptible
  • +/- 5 STC change is clearly audible
  • +/- 10 STC change is twice as loud ***

NOTE: There’s no benefit to having windows with a higher STC rating than the exterior walls and ceilings.

STC: 55  Brick, insulated exterior wall.

STC: 45 Stucco, insulated exterior wall.

STC: 39 Fiber-cement siding, insulated exterior wall.

STC: 35  Vinyl siding, insulated exterior wall.

NOTE: Noise Exposure From Windows Is Small In Relation To Walls & Ceilings.  Later in this article we give details about how to increase noise-reduction of walls & ceilings.

** Source: https://www.washingtonpost.com/lifestyle/home/do-your-windows-let-in-too-much-noise-heres-a-primer-on-sound-dampening/2018/12/10/45199a8c-f801-11e8-863c-9e2f864d47e7_story.html

*** Source: http://www.thewindowman.com/sound-basics-p13.asp

Sound-Reducing Replacement Windows 

  • STC 50+ Sound-Reducing Replacement Windows
  • Moonray’s DeVAC 600 Series Aluminum Replacement Windows Achieve STC ratings greater than 50

Sound-Reducing STORM Windows 

  • Sound needs air to move.  Sound doesn’t move well in dead air space.  Dead air space is defined as an area where air can not freely move.
  • 1/2 inch — 3 inches of dead air space between the primary & secondary window pane causes some of the sound to die.
  • The more dead air space between the primary & secondary window panes — the more the noise reduction.
  • This is why storm windows provide better sound control than replacement windows.
  • STC: 25 Common Storm windows
  • STC: Up to 50 Existing Single-Panel Glass Windows PLUS Storm Windows
  • Moonray Brand Storm windows have an STC rating of 29 to 33. **
  • STC: Up to 56  Existing Single-Pane Glass Windows (STC: 25) PLUS Moonray Storm Windows (STC: 31)
  • To Learn More About Moon Ray Storm Windows — Copy This Link Into Your Browser:  https://www.monray.com/mon-ray-storm-windows/
  • STC 50+ Moonray Replacement Windows (shown above)
  • STC: Up to 50 Existing Single-Panel Glass Windows PLUS Sound-Reducing Storm Windows
  • STC: 55  Brick, insulated exterior wall.
  • STC: 45 Stucco, insulated exterior wall.
  • STC: 39 Fiber-cement siding, insulated exterior wall.
  • STC: 35  Vinyl siding, insulated exterior wall.

** Source: https://www.oldhouseonline.com/repairs-and-how-to/soundproofing-windows

** Source: https://www.monray.com/mon-ray-storm-windows/

EXTERIOR WALLS: STC: 34–55

brick home

Image Source: ShutterStock

  • Exterior walls typically have 3.5″ of insulation.  Note: 2 x 4″ lumber is actually 3.5″ thick.
  • Most DFW  homes have 4″ brick.
  • 4″ brick = STC:45. (only the brick)
  • STC: 34 Vinyl siding. **
  • STC: 37 Fiber-Cement siding (such as James Hardie products) **
  • STC: 45 Stucco **
  • STC: 55 Brick ** (STC-Drywall = 2.5 + STC-Insulation = 7 + STC-Brick = 45)

** Source: https://www.jm.com/content/dam/jm/global/en/building-insulation/Files/BI%20Toolbox/Acoustical-Assemblies-STC-Rating-Reference-Guide.pdf

 

If you are; building a new home, a room addition, or doing a renovation that includes new drywall.

New England Quiet Insul batt insulation (made of 80% recycled cotton fibers) offers far superior sound-insulating than fiberglass batts.

According To The Company:

  • STC: 45 3.5-inch Quiet Insul batt insulation.
  • STC:   7  3.5 inch batt fiberglass insulation.
  • Quiet Insu has the same R-Value (R-13) as fiberglass.
  • STC: 57 5.5-inch Quiet Insul batt insulation.
  • STC: 10  5.5 inch batt fiberglass insulation.
  • Quiet Insula has the same R-Value (R-19) as fiberglass.

**Source:  https://www.nesoundproofingstore.com/Quiet-Insul-MD-3_p_12.html

** Source: https://www.multifamilyexecutive.com/design-development/products/keep-it-down-soundproofing-products-that-wont-break-the-bank_o

 

ROOF:  STC-4 (typical home roof) up to STC-60 (with an upgraded roof assembly)

roof shingles

Image Source: ShutterStock

Roof Shingles Don’t Have STC Ratings.  Shingles Do Little To Reduce Noise Coming Into The Home’s Living Space.

Thicker Architectural Shingles May Reduce Outside Noise A Little Better Than Thin Three-Tab Shingles.

 

Shingles Materials:

Fiberglass shingles base mat is woven fiberglass covered with a waterproof asphalt coating, then topped with ceramic granules. Because of the composition of the fiberglass mat — less asphalt is needed.  This results in a lighter weight and thinner shingle.  Though less thick and lighter weight, fiberglass shingles generally carry a longer warranty.

Asphalt Shingles base mat is made of felt paper saturated with asphalt, then topped with ceramic granules.  Asphalt shingles have 40% more asphalt than fiberglass shingles.  They are heavier & thicker, and considered more durable and flexible than fiberglass.

Shingles Styles:

three tab shinglephoto of roof sewer vents

 

 

 

 

 

Three-Tab Shingle                                                            Architectural / Dimensional Shingle

Fiberglass & asphalt shingles both offer three-tab & architectural / dimensional versions.

  • Three-tab shingles have a thinner base mat, and one layer of shingles.  They look flat.
  • In Texas the average lifespan of three-tab shingles is 10-12 years.  Actual lifespan depends on the number & severity of storms they must endure. **  Three-tab shingles are more susceptible to hail and wind damage (because they’re thinner).
  • Sun-exposure also affects lifespan.  South-facing roofs have sun all day long and wear out sooner.

 

  • Architectural shingles have a heavier base mat, and two or more layers of basic shingles bonded together – creating a multi-dimensional look.
  • Architectural shingles cost is nearly double that of three-tab shingles — but they last longer because they’re thicker.  They weigh about 50% more than three-tab shingles.
  • Architectural shingles will last about 50% longer than three-tab.  They should last 15-18 years.  Actual lifespan depends on the number & severity of storms they must endure — and sun direction exposure.

NOTE: Keep in mind that more of the cost of a new roof is labor than the shingles material.  Double the cost of the shingles doesn’t double the cost of the installed roo.

** Source: https://www.designerroofing.com/blog/how-long-does-a-roof-last-in-texas/

Shingles Warranty — Versus Actual Lifespan:

  • Most shingle product warranties are; 20,25, or 30 years.  Shingles with longer warranties are thicker.  Regardless of the warranty — roof shingles in DFW don’t last longer than (up to) 20 years. **
  • Shingles’ warranties are typically prorated after the first few years — and warranties only pay if the shingles have a manufacturer’s defect — which is rare.
  • Shingles’ lifespan is affected by climate, weather, and environmental factors where the shingles are installed.  Shingles don’t last as long in DFW due to our long summers with intense sun.
  • The shingles’ asphalt is degraded by the sun’s UV rays.  As the shingles age, more ceramic granules come off — leaving the asphalt increasingly exposed to the sun.

** Source: https://www.bobvila.com/articles/1790-asphalt-shingles-101/

** Source: https://www.roof.info/shingles/warranty.html

*** Source: https://www.nachi.org/asphalt-comp-shingles-part10-64.htm

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This is Part 1 Of A 2-Part Article Discussing Ways To Reduce Outdoor Noise From Entering Your Home.  The article is written for those seeking ways to reduce outside noise from entering their current home.  These are modest to moderate cost upgrades for an existing home.  Additionally, this information is appropriate for a new home being built 

Al’s Plumbing, Heating & A/C in Plano, Texas provides maintenance & repairs for all brands of Central A/C, Gas & Electric Furnace, and Heat Pumps.  Additionally, we sell and install new HVAC Systems from American Standard (same company as Trane), Ameristar (same company as American Standard) and Coleman HVAC (same company as York HVAC).

Al’s also provides full-service plumbing maintenance, repairs, and replacements for every plumbing component in your home.  Al’s sells and installs Rheem Professional Series gas & electric water heaters, and tankless water heaters.  Al’s is near your home in; Richardson, TX; Garland, TX, and northeastern Dallas, TX.  We service all homes in northern Dallas County, TX; northern Tarrant County, TX; and southern Collin and Denton Counties with no additional travel charge.  Call Al’s today to discuss any concerns or problems you have with your HVAC System or Plumbing.  We will arrange an appointment at your convenience.