Green Glue Soundproofing
Choosing Green Glue
After doing some research of noiseproofing products that are available I decided to try Green Glue noiseproofing compound. I'm using it for a kitchen subfloor which is over the living room of our homes basement apartment. The floor will ultimately be finished with ceramic tiles.
Noiseproofing any space isn't easy and it isn't cheap. At just over a dollar a sq. foot Green Glue appears to offer the best bang for your buck though. This is based on the "Optimal" amount of Green Glue recommended by the company. Basically, they state 1 tube per 4 x 8 sheet is good, 2 tubes per 4 x 8 sheet is optimal and 3 tubes is best. I chose to use the optimal amount as according to their data using 3 tubes per sheet does offer better noiseproofing but the return on investment is less.
Application of Green Glue
Other than cost one of the other reasons I decided on using Green Glue over other noiseproofing products is the ease of application. It simply gets applied with a caulking gun. You need to have the large size caulking gun to use the product as it only comes in large tubes.
Before applying any product make any necessary cuts to your sheet and test fit it. Also make sure there is nothing in the way. If you get halfway through screwing a sheet of plywood and discover something under the sheet it will be difficult and messy to get it out.
Be sure to cut a small hole in the nozzle as the compound flows fairly easily. You can always cut the hole a little larger if need be. Be sure to leave a couple of inches around the edges for handling of plywood or drywall, whatever your application. I put a bead around the perimeter of the sheet and just applied the rest in a random pattern trying to cover the sheet evenly.
When the sheet it in place just fasten the same as you would if you weren't using Green Glue. For my tiling application I am putting a screw every four inches as was recommended by my tiling guy.
Apply the acoustic sealant to all joints or holes as well. The same company offers a product for this and is much less messy than the black type of acoustical sealant. Put the sealant on edges of any sheet already in place before installing the next one. Also apply sealant around the edges of the room and any protrusions such as pipes.
A Word of Caution
Green Glue compound is very safe to use and also has very little odour. This is true of the Green Glue acoustical sealant as well. Other acoustical sealants have a strong odour. One word of caution when using this product in a subfloor application though it can be very slippery. This is good in one way in that you can move the plywood to get it in place just right. It can be dangerous though if you forget how slippery it can be and step on it before fastening. I slipped a few times while stepping on it before I screwed it down.
At the time of writing this article I cannot say for sure how much noise reduction I am seeing. I still have to install a few sheets of subfloor and caulk around. I don't get a lot of noise coming up from the apartment either, I mainly did this for the tenant as I have small kids and know they can be noisy. When everything is done I will go down and get someone to make noise upstairs to see if there is any difference. Not a very scientific approach but I should be able to tell if the Green Glue was effective as I was down there prior to doing this and saw how noisy it can get. I've read nothing but good things online from people who tried this product and am hopeful it will provide a significant noise reduction for me.
Update: I've spoken with my downstairs tenant who says that there is a noticeable difference in the amount of noise he hears from upstairs.