One of the best ways to make your project look and feel great is knowing about foam. Pick the wrong thing and your may feel you are sitting on a board or in a bucket. Chose the right foam, and you will add years to you comfort and the life of your furniture. Easily 25% of all furniture repairs I see deal with bad padding. The point is start with good foam and you won’t be sorry. Although some might not want to be believe this, but cushion fill is one of the easiest things to understand in upholstery. There are only 2 simple things you should know.
Foam has 2 basic element Density and Firmness. Density or weight which is the first element and this tell you how much material goes into the product i.e. the more it weighs the higher the density and the higher the density the higher the weight. The second element tells you the firmness of the product. which is how much weight it takes to compress the foam 1/3. That is a 1 cubic foot block of foam will compress 1/3 when a weight equal to it firmness number is placed on the figure. These elements are expressed in numbers as Density / Firmness. Here is an example of two 15/15 and 29/52.Since we know what each set of numbers represents, Density / Firmness (or we can also say Weight / Firmness), we can figure out the destiny and firmness of our foam.15/30 = 1.5 pounds of padding per cubic foot will take 30 pounds of weight to compress the block 33% or 1/3. And 29/52 = 2.9 pounds per cubic foot and it will take 52 pounds of weight to compress this block 1/3. See not so hard as some might lead you to think. Now what does this mean to you and your furniture?
Here are some simple rules to consider to help guide us: For seats the thicker the padding the lower compression weight we want. For seats the thinner the foam the higher the compression weight we want. For seats we want a high density foam no less then 2.2 For backs we want a density no higher then 1.8 Make all our foam 1/2 inch bigger all the way around then your cover or pattern i.e. 4 inch boxing = 5 inch foam, 29 inch wide seat = 30 inch, 18 inch seat board = 19 inch foam and so on. This way you will have a nice tight seat. Always rap our foam in bonded dacron or fiber batting. I’ll make it even simpler and let we know what destiny/firmness I would consider for my projects using the above information.
Seat: Dining room chairs 1.5 to 3 inch foam 29/52 Chair, Sofa, and love seat 4 to 5 inch 25/35, Chair, Sofa, and love seat 6 to 8 inches go 22/30.Note: These numbers are industry guides not rules. So there is some variation in numbers like 28/53 instead of 29/52 but basically the same thing. Just a mill change. Keep in mind we want the highest density you can get for the firmness we chose. In choosing high-density we add years to your comfort.Firm low-density products may go as little as a few weeks or months until we start to see or feel it losing it’s comfort and shape. Hence most warranties do not cover “foam losing its shape or getting soft.”