In light of the recent Chicago Tribune series, “Playing with Fire” about the deceptive campaigns waged by manufacturers of flame retardants, it seems that with each call we get, we end up talking about flame retardants. We think that’s skewed, because flame retardants, though certainly something we wouldn’t want to live with, are not the only monsters in the dark. So we want to talk again about what makes a “green”, “safe”, or “sustainable” sofa – whatever you want to call it – and how to evaluate manufacturers claims. What we mean is a sofa that does not compromise your health – or mine. So you can live with a sofa which does not contain chemicals which can harm you, but if a manufacturer does not capture the environmental pollutants created during the process, the end result will be the same – it will just take a bit longer.
So we’re going to do a series of blog posts on the various components of a sofa, so you’ll be better able to evaluate the claims manufacturers are making.
The first order of business is to find out what makes a “quality” sofa. In looking at what makes a “quality” sofa, I didn’t pay any attention to the “green” (or not) attributes of each item – we’re simply talking about quality so you’ll be able to evaluate a sofa. After all, it’s not a “green” option to buy a sofa that you’ll have to replace in two years. Think about furniture you see in museums that have all their original parts – including fabric – and are often hundreds of years old. That’s what quality components can do for you.
These are the components of a typical sofa:
- Foam (most commonly) or other cushion filling
- Metal springs
- Jute webbing
The frame, seating support, cushion filling and decorative fabric all determine your sofa’s level of comfort, and its ability to retain its shape and stability in the years to come.
How long a sofa will last, and retain its shape, depends largely on the frame, and a high quality sofa will always have a strong, sturdy one. A higher quality sofa uses kiln-dried hardwoods – this process removes all moisture from the frame, enabling it to retain its shape and stability over a long period of time. Green and/or knotted wood can shrink or crack. Some better quality sofas use plywood, but if you have to choose a sofa with plywood, make sure it has 11 – 13 layers of plywood and not fewer. Lower quality sofas use particleboard /MDF board.
In a high quality sofa, special attention is paid to the joints, which are dowelled or screwed into place rather than glued. Some manufacturers even cut costs by using watered down glue. Joints are secured with corner blocking, dowels and screws, which last longer than just glue and staples.
Regarding seating support:
- The best seating support is the eight-way hand tied springs system. The craftsman connects each spring to the adjoining one with a strong twine. The twine passes front to back, side to side and then diagonally in both directions thus tying each spring securely.
- Another seating support system is sinuous spring construction. Sinuous springs are “S” shaped and run from the front of the seat to the back. These springs are supported by additional wires that cross from side to side. This also makes for a strong seat, and it might be the preferred option in a sleeker style as it requires less space.
- The third option is web suspension in which bands of webbing cross the seat and back. These are then attached to the frame to make a platform for the cushions. Webbing can be made of either natural or man-made fibers, and if used alone doesn’t make for very strong support. However, in better quality sofas, it can be used with a tensioner that fastens the webbing securely to the frame. The web suspension is the least preferable of the seating support options.
Ticking is used between the upholstery foam or latex and the decorative fabric cover; stitches are even and not bunched.
The most common filling used in sofa cushions is high density polyurethane. Density is measured in pounds per cubic foot (PCF). And of course there is a lot of variability in density – it can run from 1.2 PCF for lowest quality foam, to 1.7 PCF for average quality sofa cushions and up to 2.2 PCF for high quality cushions. Firmness and resiliency are qualities that make a higher quality foam. Natural latex is another filling option, and also comes in varying densities. The lifespan of polyurethane averages 10 years; latex is supposed to have double that life expectancy. Before there was polyurethane foam, however, people used a variety of materials, such as horsehair and cotton or wool batting.
Fillings can be wrapped in softer material such as wool, cotton or Dacron, which is the cheapest option. Down is considered to be the premium filling choice, and is among the most expensive choices, but cushions filled only with down require daily maintenance. High quality down cushions will have down proof ticking under the upholstery fabric to prevent feathers from poking through.
Down used in combination with other materials is another option, but also expensive. Pads made out of a Dacron® polyester fiber and down, known as Blendown pads, are wrapped around high density foam. These pads can also be used with springs that have been wrapped up in foam. High density foam surround the springs that are then wrapped in down pads. The result is a soft surface with a strong, resilient support inside. This is a good option as the cushions do not lose their shape easily.