Green glue in the beef up between studs method

I read somewhere, can't remember where , that green glue is not very effective unless used on 4 x 8 sheets of material. Is this true? I was sure I have read here about guys using GG on material in between studs, ala "beefing up" , as we call it. Is GG effective in this case?

Personally, I don't think it would be worthwhile doing that, but I may be wrong. I'd suggest that you write to Green Glue company directly, and ask them! I know at least one person from GG used to post on the forum regularly, so they certainly should be familiar with the "beefing up" concept! Actually, it would be nice if they were to continue posting here, as their input was very helpful, and they never tried to promote their product: they were just here to help, not to sell. Very unusual in a manufacturer, and very appreciated! You could remind them that the forum is still here, and they are welcome to drop back in, if they feel like it. :) Maybe send them a link to this thread, and ask them to comment directly. That would be useful information. - Stuart -

I did the majority of my acoustical dampening using Tremco synthetic rubber acoustical sealant. Tremco is a Canadian product and is mineral based. Tremco stays flexible and it will stay in place even when it is used in a vertical gap. Menards now carries Green Glue, which is water based and odorless and it works okay when used between sheets of drywall or wood. I believe Certainteed now owns the product.

However, be aware of its water based properties when using it in door jambs, or around window frames. ... I used Green Glue between the framing and the door jamb of the equipment closet door.

You seem to be confusing products, and using the wrong product for the wrong purpose!!

Two things happened, a large portion of the green glue oozed out and the door jamb absorbed the water from the remaining glue that stayed in place. The jamb swelled and now the door will not close.

It's not surprising it didn't do what you expected, since that's not what it is for. To clarify: Green glue is NOT glue, and is NOT acoustic sealant, and is NOT caulk, but that's what you were trying to use it as. Yes Green Glue company also makes acoustic sealant, but their main product, what you used, is just called Green Glue, and it is is not in any way intended to be used as sealant, caulk, glue or adhesive. That is not its purpose. It serves one single purpose: constrained layer damping. That is all it does. You spread it between two layers of drywall (or other isolation materials) to act as a visco-elastic polymer between the two layers, damping certain types of internal resonance and also helping to decouple the panels for some low frequencies, to a certain extent. The reason it ran out all over the place when you used it wrongly, is because that is what it is SUPPOSED to do! It is designed to never set, never harden and remain "visco-elastic" permanently. Which is why it cannot be used for what you tried to do. The instructions that come with it explain this, and so does the Green Glue web site.

I would highly recommend not using Green Glue in vertical gaps or other areas such as around doors and windows where the wood will absorb the moisture in the Green Glue and cause the wood to swell.

I would also recommend the same thing, since that is not the purpose of Green Glue at all! Using it like that is the wrong use for a good product. It might have been a good idea to read the instructions and understand the uses of the product, before using it the wrong way, then wondering why it didn't work. It's a pity that you wrecked your door like that, but you can't blame Green Glue if you used their product incorrectly.

I did the majority of my acoustical dampening using Tremco synthetic rubber acoustical sealant. Tremco is a Canadian product and is mineral based. Tremco stays flexible and it will stay in place even when it is used in a vertical gap.

That's because that really is a sealant, and not a visco-elastic polymer meant for constrained layer damping. If you tried to use that stuff the same way that Green Glue is supposed to be used, as a damping product, then that would not work either! That would probably degrade your isolation badly, instead of improving it. Two very, very different products, for very different purposes. Sealant compound is not meant to damp, and Green Glue compound is not meant to seal.

This picture shows the Green Glue oozing down the outside of the door jamb. We used masking tape and cardboard to try and keep the glue in the jamb but some of it still oozed out at the very bottom leaving a big gob of green glue on the floor.

Once again, that's not surprising at all, since you were trying to use a constrained layer damping compound to do something that it simply was not intended for. It is not meant to be used as caulking. I just checked the FAQ on their web site, and they are very, very clear about this. Question number 5 there asks: " 5. Are there any places where I should not use the Green Glue Noiseproofing Compound? Yes, there are a number of circumstances where the Noiseproofing Compound should not be used, including, but not limited to: In place of the Green Glue Noiseproofing Sealant – i.e. in joints and cracks. Between the stud and the first layer of drywall – this will not offer any benefit. Between one or two soft layers – i.e. between a carpet pad and plywood. To fill any cavities, such as inside a wall for insulating purposes. The general rule is that the Green Glue Noiseproofing Compound should only be used between two rigid layers, and the thicker the layers, the better. For example, when adding another layer of drywall to an existing wall, we recommend adding a layer of 5/8” drywall rather than a layer of ½” or 3/8” drywall." More details here: http://greengluecompany.com/tools/frequ ... -questions

Picture shows how Green Glue oozed down the inside of the door jamb to the base of the door jamb. You can see the edge of the oak door on the right slightly overlapping the white jamb. I discovered how the jamb had swollen from the moisture in the Green Glue the next day after the Green Glue was in the jamb for approximately 18 hours.

Green Glue takes 30 days to cure, not 18 hours. But anyway, to fix the damage, you'll probably have to take the door out, take the drywall off, replace the studs, replace the drywall, and replace the door frame. Once you damage wood like that with water, you don't have much choice. Maybe the wood can be planed, sanded or otherwise repaired, but I wouldn't count on it.

... now carries Green Glue, which is water based and odorless and it works okay when used between sheets of drywall or wood

It worked well for that, since that is what it is designed for.

I believe Certainteed now owns the product.

Not according to their web site! They still claim that they are part of "Saint-Gobain Performance Plastics". - Stuart -

Stuart, I know green glue isn't a glue. I didn't apply it in the door jamb as a "glue." I applied it as a dampening agent. I saw the green glue at Menards and the tube had no use limitations nor warnings. Since it stated it is a sound dampening agent, just as Tremco stated it is a sound dampening agent, I assumed it would work similar to Tremco. Tremco will work in the same situation (door jamb, vertical gaps) with minimal sag and not cause the wood to swell. Tremco acoustical sealant is a "one-part, non-skinning, sound dampening sealant." Tremco also remains more flexible than green glue over time. I've seen this over the past couple weeks where both green glue and Tremco squeezed out between 2x4s. The Tremco remained flexible and the green glue stiffened up. Tremco is designed not only to seal joints, but according to their own data sheets, it is also designed to increase STC when applied between layers of drywall. The attached picture seems to indicate a merger. I'm not sure why you seem to have this need to exclaim your points, that is not conducive to meaningful and productive one-dimensional communication. Uno

I applied it as a dampening agent. I saw the green glue at Menards and the tube had no use limitations nor warnings. Since it stated it is a sound dampening agent, ... Tremco stated it is a sound dampening agent ...

Actually, the GG tube says that it is a "noiseproofing compound", not a "sound dampening compound". And as far as I know, Tremco does not present their product as a "sound dampening agent" either, but rather a "sound dampering" agent. "Dampening" is very different from both "dampering" and "damping", and they are all very different from "noiseproofing". Terminology is rather important, and understanding the difference in meaning between similar sounding words is part of linguistic skill. You question my linguistic skill, yet your own skills in that area seem to be somewhat questionable, as evidenced by this confusion in meanings and uses.

I assumed it would work similar to Tremco.

That's where you went wrong: "assuming" is generally not a good idea in acoustics.

Tremco also remains more flexible than green glue over time. I've seen this over the past couple weeks where both green glue and Tremco squeezed out between 2x4s. The Tremco remained flexible and the green glue stiffened up.

Once again, that's because you used it incorrectly, in the wrong application, not as the manufacturer instructs. Any observations you make about how it behaves when used incorrectly, are obviously invalid and meaningless. What matters is what has been tested and proven in independent laboratory tests, and shown to work, time after time, under many different situations, with many different materials. But only when used correctly, of course.

Tremco is designed not only to seal joints, but according to their own data sheets, it is also designed to increase STC when applied between layers of drywall.

Actually, no, that isn't true. You seem to have misunderstood the Tremco instructions too! They do NOT suggest that it can be used as constrained layer damping between sheets of drywall, as GG can. What their data sheets ACTUALLY say, is this: Basic Uses Tremco Acoustical Sealant was developed for acoustical sealing of drywall partitions, corridors and party walls. Also used as a lap joint and perimeter sealant for polyethylene vapor barriers over fiber glass batt or other insulations. May be used in contact with polystyrene. Features/Benefits The application of Tremco Acoustical Sealant greatly increases the Sound Transmission Class (STC value) of a system and reduces the decibel level when one or more beads are applied to a joint. See edge details. (taken from here: http://www.tremcosealants.com/fileshare ... nglish.pdf ) The "edge details" graphics clearly show the different STC ratings that can be obtained by using various numbers of beads of this product, in the gaps around the edges of walls. The data sheet says noting at all about applying it between layers of drywall. I'm not sure how you can read that to mean "it is also designed to increase STC when applied between layers of drywall." The manufacturer makes no such claim. It's not meant for that, and would not work for that. All they talk about is joints, where it doubtless does work as advertised. But not as CLD: It is a joint sealant, and works like a sealant. If you really did try to use Tremco sealant as a CLD, by applying it between layers of drywall in the manner in which Green Glue should be applied, then that, too, will fail to work the way you think it will.

I'm not sure why you seem to have this need to exclaim your points, that is not conducive to meaningful and productive one-dimensional communication.

That's your opinion on my linguistic skills, and you are, of course, entitled to it. But since I write for a living (quite successfully), I think I'll just ignore it and assign it the same validity as I assign your opinions on how Green glue and Tremco products should be used. :) :!: - Stuart -

dufo wrote:

I read somewhere, can't remember where , that green glue is not very effective unless used on 4 x 8 sheets of material. Is this true? I was sure I have read here about guys using GG on material in between studs, ala "beefing up" , as we call it. Is GG effective in this case?

Hi dufo, When I was in the 'beef up' stage of my project, it required 2 sheets of 5/8" drywall to be installed inside the joist opening. The recommendation I received [I believe from Gullfo] was the use of GreenGlue would provide 'similar' results to adding an additional layer of drywall. Since it was SO MUCH FUN getting that 1 layer installed :shock: and NOT wanting to, possibly, NOT maximize this important 1st step. I purchased enough cases of GreenGlue to also include the beef-up process. From MY research ... it seems that GreenGlue just BEGINS to affect after 1 month, but may be more like 3 months before fully 'cured' [not the right term I suppose]. As for results ... well, since I have a Room within a room build, there is no direct way to test this. What I CAN say ... the INTERIOR walls of my 'inner wall' build that comprised 2 layers of type-X, 5/8" drywall WITH 2 tubes per 4'x8' surface area, have an entirely different resonant property than my single layer wall !!! AND from an early 'test' assembly, I had JUST the 2 drywall layers on a 'silencer' box build I was testing. The quick, dead thud, of hitting the GG wall is quite significant. Though the price may be prohibitive ... I'm glad I went the GG route for my entire build. The LABOR and material cost [and ESPECIALLY my body] also agree with that decision :mrgreen: I'm sure there is hard data available somewhere ! In FACT ... a call to the GG guys would be good too! I found them extremely knowledgeable AND helpful ... and insisted that if any question arose to not hesitate contacting them in person. Very nice. Don't know ... but I hope this helped a bit. 8)

Soundman2020 has the exact correct dialog with respect to the use and function of the Green Glue. It is effective to damp vibration when placed between sheets of drywall, plywood, cement board, or some combo thereof. A thin film is desired. Thick films don't damp particularly well. Too little damping compound and you can't generate enough resistance from the shear forces. Similarly, too thick a layer will also offer insufficient resitance to shear and no damping occurs. It appears i the images that the product was used in the wrong way. This is the danger of selling technically difficult projects / products from Menards. A sealant seals, and will not damp, regardless of an offhand claim on a label.

Thanks for chiming in Ted, and good to see you posting here again! :) Do you have any suggestion on the original question, about using Green Glue between layers of drywall when using the "beefing up between the studs" technique on basement ceilings? Is that worth doing with GG, or would the results not really justify the effort/cost? - Stuart -

Hi Stuart. Thank you! Green Glue on the edge of a stud or joist (I believe this is what the OP is referring to) is a waste. Just apply the drywall to the bare stud or joist, no GG or adhesive. This allows the board to have maximum flex, and therefore max shear and damping.

I think he's talking about cutting strips of drywall to put up between the joists, tight against the sub-floor above, in order to add mass to that floor, which will then become the outer-leaf of a 2-leaf system. I think the question is this: since the drywall will be cut into strips about 14"-and-change wide, instead of being applied as full sheets, does it make sense to still use GG between those layers? With this "beefing up" technique, the drywall is normally held in place against the subfloor above it, using cleats around the edges that are nailed sideways into the joists, and caulked around the edges, so it isn't really the normal way GG is used. I'm sure there will still be some damping effect from the GG, since it will be doing its visco-elastic thing to a certain extent, but the original poster here is curious about the cost/benefit of doing that. Is the effect worth the trouble? Maybe it would be more use on the second layer of drywall applied like this, rather than on the first layer, considering all the unevenness usually seen under subfloors! It's a good question: I've wondered about it myself before, so it would be good to get your thoughts on that. - Stuart -

Ah. Thanks for the clarification, Stuart. Very kind of you. This is a common ceiling noise remediation. The general recommendation is for two layers of 5/8" drywall and damping compound to be secured to the underside of the subfloor with drywall screws. The screws provide the compressive force to squeeze the damping compound to a thin film. If we want to damp the subfloor itself (we do) then it's important that the damping compound be in direct contact wih the subfloor. Having said all that, I would not recommend doing this unless footfall noise (impact) were an issue into the room below. For isolating sound within the room below, I would focus on decoupling the ceiling (damped) mass from the joist with isolation clips.

Thanks Ted. Your input is much appreciate, and what you say makes sense. Kind of what I expected. - Stuart -