How Many — Cans Of Spray Foam Will Fill A 55 Gallon Drum

💡 If you are filling the drum for flotation or insulation, ensure you use "Closed Cell" foam. Open cell foam can absorb water over time, which will make the drum heavy and prone to mold.

However, the answer is surprisingly complex. Spray foam expands, but not indefinitely. Between different foam formulations, waste factors, and application techniques, the number can vary wildly.

Temperature: Foam expands best in warm, humid conditions. If it is too cold, the foam will stay dense and you will need significantly more cans. how many cans of spray foam will fill a 55 gallon drum

Let’s break down the math and the real-world variables.

7.35 cubic feet (drum) ÷ 0.5 cubic feet (real yield) = . 💡 If you are filling the drum for

A standard 55-gallon drum has a total volume of approximately 7.35 to 7.53 cubic feet . Since a single 12 oz can of expanding foam (such as GREAT STUFF ) typically yields about 0.27 cubic feet

Calculating the number of cans is rarely a perfect science because environmental factors change how the chemicals react. Spray foam expands, but not indefinitely

The "1 cubic foot" yield assumes you spray a thin layer on a flat wall. When you spray into a deep, enclosed drum, three things happen:

But why the huge range? Let’s dig into the variables.

If you fill the drum only 80% with foam, the top 20% is air. That air can leak, causing the drum to sink. Therefore, for flotation, you need 100% fill. You will need to ensure no voids.

Filling a 55-gallon drum (approximately 7.4 cubic feet) typically requires between 4 and 9 cans of spray foam, depending on product yield and expansion. High-yield cans can fill the volume with about 4 cans, while standard retail cans may require 8 to 9, requiring layering and moisture for proper curing. For more details, visit Fine Homebuilding . Hey, Does it Float? - Spray Foam Magazine