Understanding your result
The headline is the number of tubes, grouped into cases of 12, or the number of 5 gallon pails if you chose pails, and the line under it gives the area of the second layer and the rate. The tiles give the tubes per sheet at your sheet size, the pails or tubes as the alternative packaging, and the tubes of sealant.
The rate is per 32 sq ft, one 4 × 8 sheet, because that is how the maker states it. A 4 × 12 sheet is 48 sq ft and takes three tubes at the recommended rate, which the calculator handles; counting “two tubes a sheet” with 12 ft sheets under-buys by a third.
Sealant is counted at the maker’s guide of about one tube for every six tubes of compound, enough for the perimeter of the layers and the gaps around electrical boxes. What a damped double layer does to a wall’s rating is on the soundproofing assembly calculator; the alternative of adding mass with a membrane is on the mass-loaded vinyl calculator; for ceilings, damping and isolation clips are often combined.
How we calculate this
The rates and package sizes are the maker’s published figures: two tubes per 4 × 8 sheet recommended, one to three allowed, cases of 12 covering about 192 sq ft, and a pail covering about 365 sq ft. A 5 gallon pail holds 640 fl oz, which is 22.9 tubes of 28 oz, so the pail and tube figures agree. Damping compound is applied only to the second layer, so count the sheets of that layer, not of the whole wall. Board sizes for the area are on the sheet sizes table.
The assumptions behind the numbers
| Assumption | Default | Where it comes from |
|---|---|---|
| Rate | 2 tubes (28 oz) per 4 × 8 sheet | Green Glue Company recommendation |
| Minimum and maximum | 1 and 3 tubes per sheet | Green Glue installation guidance |
| Case | 12 tubes, about 192 sq ft | Green Glue product data |
| Pail | 5 gal, about 365 sq ft (≈ 22.8 tubes) | Green Glue product data |
| Sealant | 1 tube per 6 tubes of compound | Green Glue installation guidance |
| Sheets | 12 of 4 × 8 | A wall about 12 × 8 ft on both sides, or 24 × 8 on one |
Assumptions last reviewed October 8, 2026.
The calculator does not tell you how many STC points the compound adds to your wall; that depends on the wall, and the published assemblies on the soundproofing page are the honest reference. It does not count the second layer of board itself, or the longer screws it needs; the screw calculator counts those with the double-layer length. Where damping sits among the four ways to stop sound is in the soundproofing basics guide, and its use on ceilings in the ceilings guide.
Two worked examples
A second layer of 16 sheets of 4 × 8 on a shared wall
- Area: 16 × 32 = 512 sq ft
- Tubes: 512 ÷ 32 × 2 = 32 tubes, 3 cases of 12
- Sealant: 32 ÷ 6 → 6 tubes
- In pails it would be 2, but at this size tubes in a caulk gun are simpler
Thirty-two tubes is a lot of trigger squeezing; a large-capacity caulk gun or a battery gun makes the second layer go up in a day.
1,400 sq ft of second layer in pails
- Tubes’ worth: 1,400 ÷ 32 × 2 = 87.5
- Pails: 87.5 ÷ 22.8 = 3.8, rounded up to 4 pails
- Sealant: 88 ÷ 6 → 15 tubes
At this size pails with a bulk gun save money and time; the fourth pail is part used, and the remainder keeps for the next room if the lid is sealed.
Where to find your inputs
Sheets in the second layer. Only the layer that goes on over the compound. If both sides of the wall get a second layer, count both.
Sheet size. The size of the second-layer sheets.
Rate. Two per sheet unless you have a reason: three for a home theatre where bass matters, one only where the budget forces it.
Packaging. Tubes for one or two rooms, pails for a basement or a whole apartment wall.
Common mistakes
- Counting by the 4 × 8 rule with 12 ft sheets. Three tubes per 4 × 12, not two.
- Spreading it like adhesive. Random beads across the sheet, not a trowelled film; the maker’s pattern spreads as the sheet is pressed on.
- Waiting too long to hang the layer. Hang and screw within the open time on the tube.
- One layer only. It needs two rigid layers to work.
- Gluing the second layer to the first. It is not an adhesive; the screws hold the layer.
- Forgetting the gaps. A damped wall with an unsealed perimeter and open outlet boxes leaks around the damping.
Questions people ask
- How many tubes of Green Glue per sheet of drywall?
- The maker recommends two 28 oz tubes per 4 × 8 sheet, about one tube per 16 sq ft. One tube per sheet is the minimum and three per sheet is the heaviest rate it recommends, which helps a little more at low frequencies. A 4 × 12 sheet takes three tubes at the recommended rate.
- How much Green Glue for a wall?
- A 12 × 8 ft wall with a second layer on one side is three sheets of 4 × 8, six tubes at the recommended rate. A case of 12 tubes covers about 192 sq ft, which is six sheets or two such walls.
- How far does a 5 gallon pail of Green Glue go?
- About 365 sq ft at the recommended rate, roughly 22.8 tubes' worth or eleven 4 × 8 sheets. Pails need a bulk dispensing gun, and they make sense from about 1,000 sq ft of second layer.
- Do I need two layers of drywall for Green Glue?
- Yes. Green Glue is a damping compound that works between two rigid layers, usually two layers of drywall or drywall over plywood or existing plaster. On its own, or behind a single layer, it does nothing useful.
- How long does Green Glue take to work?
- The second layer is screwed on within the compound's open time, and the compound then cures over the following weeks; the maker says it reaches full performance as it cures. The wall can be taped, finished and painted as normal in the meantime.
- Is Green Glue worth it?
- Damping compound between two layers typically adds several STC points over the same two layers without it and helps most in the low-to-mid frequencies where a double layer alone is weak. It is cheaper than decoupling an existing wall, which is why it is the usual choice when the wall cannot be opened.