Are you jolted by the sound of footsteps from the room above? You’re not alone. Footsteps are the number one noise complaint of homeowners. But it’s not the only interior noise that can ruin the peace and tranquility of your home or office. There’s also unwanted music from a stereo system, or a home theater, or even just a noisy washing machine. Whatever it is, protecting yourself from unwanted noise is one of the most important considerations in renovating your home or office, or when planning new construction.

If you are going to be starting from scratch on a project, visit our New Construction Page. If you are working on existing walls, floors and ceilings, using the right materials, designs, and Green Glue Noiseproofing Compound will help bring some peace to your home life—so you can enjoy the benefit of quiet.

FLOORS AND CEILINGS

If ceilings cannot be removed your options are limited, and you may still encounter flanking noise. But these tips will help:

• Blow insulation into the ceiling cavities if they aren’t already insulated.

• Apply Green Glue Noiseproofing Compound and an additional layer of drywall to the existing ceiling if airborne noise, not impact noise, is the primary concern.

If ceilings can be removed, you have a good shot at reducing most of the noise from the floor above. Here’s how:

• Once the ceiling is removed, you can upgrade the floor above from below by treating it with Green Glue Noiseproofing Compound and layers of drywall, plywood, and OSB (see diagram below). Even if ductwork or structures get in the way, this will help. Using multiple layers will be especially effective against airborne sound.

• Next, upgrade the ceiling with Green Glue products and other materials using these methods. We list the best method first, followed by measures that will help, in order of their effectiveness:

• For the most effective sound isolation, separate ceiling joists and wall studs with double drywall and Green Glue Noiseproofing Compound.
• If the above method is not possible, use sound clips like Green Glue Noiseproofing Clips or spring ceiling hangers with double drywall and Green Glue Noiseproofing Compound; or clips or staggered studs with Green Glue Noiseproofing Compound on the walls.
• If you choose the method above but neglect the Green Glue Noiseproofing Compound with the double drywall, you will still have noise isolation, but it will be less effective.
• A less effective method is to install resilient channel and Green Glue Noiseproofing Compound with double drywall on the ceiling, and furring or directly-screwed drywall with Compound on walls.
• Less effective—but still possible—is to use Green Glue Noiseproofing Compound with double drywall and metal hat channel or wood furring strips perpendicular to the joists and studs, 24" on-center.
• If none of the above methods are possible, you will still get some noise isolation by using Green Glue Noiseproofing Compound and double drywall screwed directly to the joists and studs.

• If you have exposed joists, using Green Glue Noiseproofing Clips or comparable clips, or spring hangers can still be effective at isolating noise.

• Do not use sound clips, resilient channel or spring ceiling hangers over existing drywall as this creates a triple leaf effect.

• For better performance, we recommend using resilient channel in conjunction with Green Glue Noiseproofing Compound.

WALLS

When it comes to noiseproofing walls, you first must decide whether to work with the existing walls (non-destructive upgrading), or to tear out existing walls (destructive upgrading). Destructive upgrading is more effective, but it costs more and requires more time. The choice is yours.

Here are some wall noiseproofing tips:

• Remove direct air paths between rooms by sealing cracks covered by wall trip, unsealed doors, and pathways that involve the ventilation system.

• Add an extra layer of drywall with Green Glue Noiseproofing Compound. Just adding a drywall layer alone only improves a wall’s STC rating by 2 points. Adding a double drywall improves the STC rating by 4 points. But when you add compound with the additional mass, the performance dramatically improves—raising the STC rating 12 points for a single layer of drywall, and 16 points for a double layer. See chart below.
   
• Adding resilient channel or modern sound clips to the wall and then adding drywall is not recommended because this can create a Triple Leaf Effect.
   

Wall Type	Lost Floor Space	STC (gains)	31.5-5,000Hz dBA reduction (gains)	$$$/STC	$$$/full band dBA
Unsealed Reference Wall	0	26	26	--	--
Reference Wall	--	40	38	$0.10	$0.12
Add Drywall to One Side	0.625"	42 (2)	40 (2)	$0.47	$0.47
Add Drywall to Both Sides	1.25"	44 (4)	42 (4)	$0.47	$0.47
Add Soundboard & Drywall to One Side	1.125"	45 (5)	43 (5)	$0.41	$0.41
Add Green Glue & Drywall to One Side	0.625"	52 (12)	47 (9)	$0.18	$0.23
Add Green Glue & Drywall to Both Sides	1.25"	55 (15)	51 (13)	$0.25	$0.29

All data based on tests run at Orfield labs, an NVLAP certified independent lab. Costs based on national averages from the National Construction Estimator, available from Craftsman books. 31.5-5000Hz dBA reduction is based on the sound reduction over this entire frequency range for a flat noise source.
Please note wall construction details: 2x4 wood studs at 24'' o/c with insulation in the cavities
 

Understanding the Triple Leaf Effect

In its simplest form, a triple leaf wall is a wall with TWO air cavities, not just one as in a typical wall. (In case you’re curious, a quadruple leaf wall would be a wall with 3 air cavities).

Why is a triple leaf wall a bad thing? After all, it would seem to make sense that any wall structure that has more air cavities for the noise vibration to cross would be more effective at reducing sound transmission. Unfortunately this is not the case.

The reason lies in the science of decoupling. Decoupling isn’t effective at all frequencies. If you take two layers of drywall, and separate them with an air space, it doesn’t necessarily improve things at low frequencies (the deep bass from your neighbors subwoofer), for example, which can pass easily even through decoupled walls. The air in the cavity acts like a spring, and creates a continuation of the vibration, called resonance. To attain good low frequency performance, this resonance must be as low in frequency as possible, however for any given mass and space, a triple leaf wall will always have a higher resonance point than a double leaf wall.

Triple leaf (or higher) constructions should be avoided at all costs. You will always get a lower level of sound isolation, and this loss may be most severe where you need performance the most – low frequencies. For more information on the Triple Leaf Effect, download the datasheet in our Technical Library.

INSULATION

Many homeowners think that simply adding insulation will improve noiseproofing. While insulation is important, you may find that insulation alone will not significantly impact the sound isolation between rooms.

Here are some tips:

• If you have conventional walls, vibrations and sounds pass easily from one side of the wall to the other, and insulation does little to help.
• Insulation works best if your walls are decoupled, i.e., there are no mechanical connections between the two sides of the wall.
• Don’t be tempted to use dense insulation thinking it will work better at isolating sound. It is more expensive and actually raises the resonance of low frequencies.
• Bottom line: insulation alone will not get rid of noise, but the inclusion of insulation in a cavity can have a tremendous impact when coupled with Green Glue Noiseproofing Compound.