TM Soundproofing How To Soundproof

How To Soundproof

Soundproofing your walls and ceilingThis sound proofing article follows the Soundproofing basic article and is intended to give a step by step instruction on how to install sound proofing for a home, hotel, condo or office that is under new construction. In Our Soundproofing Walls & Ceiling article we will discuss soundproofing for existing floors walls and ceilings.

[As in all our soundproofing 100 series of articles this is a practical short and concise article. For more in depth understanding of the science behind sound control please browse our soundproofing articles on the sidebar.]

Floors:

Being that the sub floors are put down as part of the framing we will begin with the floors.

The Challenge: Aside from airborne sound coming through the ceiling, soundproofing floors face an additional challenge called impact noise (e.g. footsteps). One reason is that heavy footsteps actually shake the whole structure, thus making it difficult to control. Again this is one reason why lab tests are not so reliable in testing impact noise called IIC (Impact Insulation Class). The reason being that they use a tapping machine which does not compare to heavy footsteps above. There are many underlayments being sold, some at very steep prices, and we cannot claim that we have tested every one of them. We can say from the amount of customers calling Trademark Soundproofing complaining about inadequacy of their floor systems, that our system is the best we know of, at a fraction of the cost.

The Solution: We try to utilize as many techniques as we can in the floor/ceiling system due to the complexity of the system as mentioned above. Therefore, we will start with the best system and give an option of a lesser degree for those of you who are on a budget.

  1. Start by applying Gasket Tape on each of the floor joists (a typical roll has 100 feet of tape). This closed cell tape will give some flexibility and decoupling to the floor. An additional consideration is that this will solve any future floor squeaks. Floor squeaks occur when the sub floor loosens from the joists and then rubs against each other. The Gasket Tape will ensure that the friction will not occur. 
  2. Install your sub floor on the gasket tape covered joists and apply Green Glue Damping Compound, using two tubes for every 4x8 sheet (if you are on a budget you can skip this first layer of Green Glue).
    Cover with 1/2" sound board. (Install perpendicular to the sub flooring in order to stagger seams).
    Apply another layer of Green Glue on top of the sound board and cover with sub flooring (plywood).
  3. Caulk the perimeter of the room with a high quality Acoustical Caulk to ensure a proper seal on your job.
  4. Install your floor as you would any sub floor. If you are using carpet, install the thickest carpet pad possible.

You have now completed half of your work - the other half will be working on the ceiling from below, as follows.

Ceilings:

  1. Cut strips of drywall to fit in between the ceiling joists. Apply Green Glue on the strips and screw into the underside of the sub floor sandwiching the green glue between the sub floor and drywall, you can double up by doing the same thing with another strip of drywall over the first. This step may be omitted if you are on a budget or if it involves to much labor for your project.
  2. Install R-19 fiberglass batts in between your ceiling joists; be sure to put some on top of any recessed lighting that you may have. (We generally find that if the floor and ceiling are done as described, we do not have any issues with the recessed lighting. However for the perfectionist, or in a case when there really are a lot of them, they may need to be boxed around. The method for doing that will be discussed in a different article. Some information is available here.)
  3. Install Resilient Sound Clips on your ceiling joists as follows:
    • The first clip should be installed within 6" of the wall (when installing a ceiling); the following one, 48" away which would be on the third stud on a standard 16" on center framing. In other words, you would install one clip, skip two studs, and then install a 2nd clip on the 3rd stud, continuing this pattern until you reach the opposite wall.
      Remember: You must install a clip within 6" of the opposite wall as well, which will sometimes be closer to the last clip than 48".
    • The next row should be started 24" down from the first row, (twenty four inch on center will give the wall more resiliency, thus enhancing the soundproofing capabilities of your ceiling).
      The first row of channels should not be more than 8 inches from the wall, therefore your last row of clips may be closer than 24 inch on center.
  4. Run 7/8 .25 gauge Hat Channel through your clips overlapping all ends by at least six inches and screwing together with self-drilling sheet metal screws.
  5. Then Raise your drywall into place and screw into channels using standard drywall screws.
  6. Apply Green Glue to the back of a 2nd sheet of drywall, using 2 tubes for every 4x8 sheet. Screw the 2nd sheet of drywall into channels using longer screws. (This step can be omitted if you are on a budget, especially if you have installed the Green Glue on the floor above).
  7. Caulk the perimeter (and the seams if you only used 1 layer of drywall) using high quality acoustical caulk. Additionally, caulk the space between the recessed lighting and the drywall.

Walls:

  1. Install fiberglass in between the studs (R-11 for a 2x4 and R-19 for a 2x6.
  2. Install Whisper Clips on the face of the studs using the following pattern:
    • Bottom clips must be less than 3 inches from the floor;
      Top clips must be less than 6 inches from the ceiling.
    • The rest of the pattern is the same as discussed above for ceiling installation.
    • Keep in mind that clips must be placed at the outermost studs at the beginning and end of every row.
  3. Follow steps 3-6 above, making sure to caulk around electrical outlets.
  4. Another simple option is to install 2 layers of drywall with Green Glue directly onto the studs.

The obvious question that we are frequently asked is: do I need the clips on the wall or is the green glue alone enough. The answer depends on what level of soundproofing you are looking to achieve, what type of noise you are trying to block, and if you have access to both sides of the wall.

If the noise you are trying to control is standard talking, phone ringing, and some music, then you will have a tolerant level by using drywall and Green Glue. Either by doing it on both sides of the wall, or by doubling up on one side (whenever possible, always try to soundproof the noise source side). However, if the noise is extremely loud or very low bass, like a loud home theater (where you can feel the vibrations), or you want the best soundproof wall available. Then you should use the clips and a double layer of drywall with Green Glue on the other side or on the clips themselves.

Hopefully this article has given you clear direction and instructions for your project. Click here to return to our sound control homepage.

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