The following reviews will tell you everything (well, almost everything) you need to know about the variety of mattress types available. Click the links below or choose an option from the navigation to the left for specifics.
1. Innerspring Mattresses
Innerspring mattresses have wire coils as the support structure. An innerspring mattress has a strong border wire attached to the perimeter of the coils. The border wire supports the coils, helping to retain shape and reduce sagging. The edge is reinforced with specially shaped springs or foam to support the sleep surface right to the edge, to help prevent ‘rollout’ and edge breakdown. The upholstery is separated from the innerspring system by an insulator, tough padding, wire or netting layer that prevents the upholstery from sinking into the coils.
Innerspring Support System
Number of Coils
Not so long ago, experts were saying that the more coils a mattress had, the more support it would give. Today, we have realized that this is not necessarily. The way that the coils are constructed is the main factor in determining the amount of support the user gets.
This all depends on the mattress size, but mattresses generally come with 300 to 800 coils. Based on a queen-size mattress, 500 to 800 coils are considered firm. However, some of the best and most comfortable mattresses only have around 400 coils, and even fewer in a full mattress will provide decent support. This can be impacted by the use of a heavier gauge wire, therefore adding more steel to the mattress.
There are a number of misconceptions with regards to coil count and firmness. Doctors once said that firmer mattresses give better support. This was actually only true with a small percentage of people who sleep on their backs and/or stomachs. Research shows that most people sleep on their sides. The side of the human body is not flat (like a back,) and a mattress that conforms better to the body and gives better support putting the spine into proper alignment or it’s natural resting position has proven to be better. Individually wrapped coils have proven to be the best factor in support for side sleepers.
It may seem obvious to most that heavier gauge (thicker wire) coils would offer a greater deal of support than lighter gauge coils. It has been proven that this is not true and some mattress manufacturers compensate for thinner gauge steel wire by increasing the coil count and specifying the type of coil.
Low coil counts and heavy gauge wires can seem firm in the store, but it is likely that such a mattress will not hold up long because it simply does not have enough coils.
Many premium mattresses feature 14-gauge (1.63 mm) coils. Coils are measured in quarter increments. The lower the number, the larger the diameter of the spring. With coils in the 14 to 15.5 (1.63 to 1.37 mm) gauge range, it is important that the total coil count is high the coils would otherwise give easily under pressure.
A 12.5 gauge (1.94 mm) innerspring coil, the thickest typically available, may feel rock hard in a double mattress even with a coil count of 400 or less.
How are the Coils Connected?
We have found that the number and quality of these interconnecting wires, or helical, is not published by the manufacturers. If there are too few of these interconnecting wires a mattress can lose its shape more quickly than one that has an adequate amount. Mattresses that sag quickly usually have few helicals. Some manufacturers make individually pocketed coils (see types below,), which disperse movement from different sides of the bed because they are not connected. However, in this case, the pocket or independent coils provide the support required by the individual coil instead of the interconnection between coils.
Types of Coils
Most manufacturers stake claim to having the best coil-to-gauge ratio. However, there are only a few innerspring manufacturers and four general types. One thing to remember is that while there are many different types of coils and many manufacturers, most manufacturers have their coils made by one company.
There are a number of different types of coils:
Open Coil or Bonnell Coil: These are the oldest and most commonly used. They were adapted from a design used in buggy seats in the 19th Century. This hourglass-shaped wire coil is joined to adjacent coils by small wire spirals called helical. The open coil design provides good initial support but these coils fatigue more quickly than more technically advanced coil constructions. You’ll know this mattress has reached the end of its life when you and your bed partner are experiencing the ‘roll together’ or you suddenly realize that your mattress feels more like a hammock.
Offset Coil: This coil construction is similar to the open coil but it has a square head, which in theory enables the mattress to contour better. It is a descendant of the Bonnell or open coil. An offset coil is slightly more cylindrical in shape than an open coil, which may make it more durable. It is also laced to its neighbors by helical. These are usually the most expensive coils.
Pocket Coil/Independent Coil or Marshal Coils: A pocket or independent coil is a cylindrical spring wrapped in its own fabric pocket. This construction is designed to give the most contour of any support system. Each coil works independently which means that you will feel your partner move much less. Each pocket coil absorbs the weight placed on it without distributing the load to other coils. Because of this, it is possible that the coils will provide less support over time, particularly for heavier people. This type of coil is a good choice for people who toss and turn and for their bed partners because the motion separation may prevent waking from a deep sleep which is very important for well being. Simmons uses this type of coil.
Continuous Coil: The continuous coil is exactly what it says – each row of coils is made of a single wire attached to the next row by helical. This type of coil is often made into a lattice of coils rather than rows, allowing more coils per mattress than other constructions. This design allows each coil to deflect weight to a great number of springs resulting in less stress on each coil. Mattresses with continuous coils keep their shape longer. Serta and Kingsdown use these types of coils.
2. Memory Foam Mattresses
NASA’s Ames Research Center funded a development project in the early 70′s designed to create a substance that would relieve astronauts of the g-forces they experience during lift-off. They found that reducing g-forces on the body was aided by using a material that conforms to a person’s body. Mold could accomplish this but any movement would create incorrect pressure points. To remedy this, they created a foam material that was viscoelastic – able to conform to a shape, but come back to original shape once pressure was removed. Fagerdala World Foams of Sweden, which at the time was one of Europe ‘s largest foam producers, perfected this type of foam for consumer use in the 80s’.
The Swedish Mattress company, Tempur-Pedic®, introduced this material in a mattress form to the people of Sweden in 1991. In 1992, Tempur-Pedic® launched products in North America. With the success of Tempur-Pedic®, other foam manufacturers like DreamFoam bedding mattress (check the reviews) developed their own viscoelastic memory foam materials flooding the market with a variety of options and price levels. With this, we also saw the use of viscoelastic foam in products other than mattresses.
Why does viscoelastic foam have memory?
Take synthetic polyurethane foam, add certain chemicals to add an increased density. As you can imagine, there are many combinations of foam and chemicals that will determine what type of memory foam you end up with. To understand the differences let’s start with understanding how foam is graded.
How Foam is Graded?
For a material to be considered viscoelastic, it has to be temperature sensitive and has an ability to return to its normal shape relatively quickly. Memory foam is graded by its viscoelastic properties and its durability in the following grading system:
Weight (Density in pounds per square foot):
The weight of a foam is determined by the quality of the foam and chemicals used in the composition of the foam. The density measurement is not a reflection of the hardness or stiffness, which is determined by the ILD rating below. You will see memory foam mattress range from 4-5lb densities to as low as 2-3lb densities.
ILD Rating (Indentation Load Deflection):
The ILD rating tells you how hard or soft the material is. The 25% ILD rating is the number of pounds required to compress a 4” sample of foam by 25% using a 50 square inch indentation. The higher the ILD, the firmer the foam. It is important to note that the ILD rating can vary from lot to lot due to the chemical reactions that take place. So an 8 ILD rated foam can vary from 6 – 10 ILD by a lot.
This measures the foam’s springiness by calculating the percent rebound of a steel ball dropped from a height of 36″. The term “H.R” foam refers to highly resilient foam with a high “ball rebound.” In general, a foam with a higher resilience will be more durable to the forces of compression.
This indicates how much the foam can be stretched, measured in pounds per square inch, and how much elongation in percent of stretch before the foam breaks. We believe this value has little relevance to mattresses because they are rarely stretched when slept on.
Memory or Latex?
In general, latex foam has a higher elasticity or resiliency than memory foam. The result is that latex will feel springy opposed to memory foam, which will feel solid. Memory foam does not feel like it is pushing up against your body. Many mattress companies are blending both and seeing good results. Sometimes allergies to latex can be triggered, but this is usually due to skin contact and does not normally occur with the latex blends that are being used today. It is thought that proteins that trigger allergies are washed away in many of the latexes used today. There are no chemicals used in latex composition, so look at the ILD rating to determine the feel of the product.
3. Air Mattresses
Air beds and air mattresses are used in hospitals and nursing homes because they are very efficient at alleviating pressure. Air beds and air mattresses distribute weight across the surface using different technology than foam and innerspring mattresses. Foam or innerspring mattresses absorb body weight but they do not displace body weight the way air beds or mattresses do.
Select Comfort introduced adjustable air beds and air mattresses to the consumer bedding industry over 5 years ago. Until that point, consumers could only choose from innerspring mattresses and futons. Initially, the price of air mattresses and air beds was very high due to the cost of raising awareness in the marketplace. With new awareness in the bedding industry, many other manufacturers have jumped into the air mattress market.
Nautilus Sleep Systems, Comfortaire, and others have entered the market and prices are dropping considerably. Much like the visco-elastic memory foam market launched by Tempur-Pedic, greater competition has led to greater savings for consumers.
4. Waterbeds Mattresses
Particularly popular in the 1970′s and 80′s, waterbeds are still fairly popular today thanks to a few unique features. The most notable advantage of a waterbed is its ability to be easily (and safely) heated. Those living in colder climates can certainly understand how pleasant it is to climb inside a nice warm bed in the winter.
To be fair, water beds have changed quite a bit since 1975 when you rolled around on your aunt and uncle’s waterbed as though you were tossing and turning in a tropical storm. Modern waterbeds come in two types, soft-sided and hard-sided. The classic waterbed is the hard-sided variety with sturdy wood sides helping to keep the water mattress rigid (and contain spills in the event of a puncture).
Updated waterbeds fall into the soft-sided category, a hybrid of a conventional mattress and a water bed. These mattresses essentially have water chambers inside a foam and fabric mattress casing. Water beds also happen to be very good for people with allergies as the outside of the bed can be wiped down to make sure no mites or pollen are present. Additionally, waterbeds have a long lifespan, typically well over ten years.
Water beds were first invented over 100 years ago but didn’t gain widespread popularity until 1968 when a design student at San Francisco State University used modern materials to make the waterbed a practical reality. Charles Hall created the basis for the modern water bed but wasn’t able to secure a patent for his work due to several instances of prior art dating back to 1871.
Unfortunately, heating a water bed can be quite expensive. A bigger bed is obviously more difficult to heat but new low-wattage heaters can help keep costs down. Still, expect to pay up to $500 per year to heat a water bed. You must also be very careful to put the water bed in an area that can sustain a lot of weight. Putting a water bed in the middle of a large upstairs room can be a bad idea.
Most mattress chains don’t sell water beds. You’re better off going to a local furniture store.
5. Futon Mattresses
Originally a Japanese mattress, western manufacturers have adopted the name for a significantly thicker version of its Japanese older brother. Japanese futons are only about two inches thick and are designed to be rolled up when not in use. Western futons, however, are typically 6-10 inches thick and are often folded up with a special futon frame to serve as a couch.
Many people like western futons because they tend to be fairly firm mattresses. They are also inexpensive compared to other mattress types and as a result, are popular with students and those on a tight budget. Urban futon owners often cite the space-saving versatility of the bed & couch frame, particularly in cramped studio apartments.
Western futons contain many of the same materials found in innerspring mattresses including wool, cotton, foam, latex, and polyester. The main difference between a futon mattress and a “regular” (innerspring) mattress is the lack of springs in the futon mattress and the stronger futon covering (sometimes canvas or heavy cotton). As the futon industry has grown since the sixties and seventies, many hybrid mattresses have been developed including innerspring futons, futons with memory foam, and futons with a wide variety of covers (including leather!). Even some of the major mattress manufacturers like Simmons have gotten into the futon market with their own line of Beautyrest futon mattresses.
Many of the larger mattress chains don’t actually carry futon mattresses, preferring instead to guide their customers towards more high-end innerspring and foam mattresses. However, a local Google search for futon retailers will surely turn up furniture and mattress stores selling futons. The Futon Shop is a popular Bay Area futon chain.
Futons can be quite heavy depending on the thickness of the mattress and the sheer amount of cotton batting filling the futon. Futons constructed from a mix of foam and cotton are usually ten to twenty pounds lighter than a 100% cotton futon. Cotton & polyester futons also weigh less than all-cotton construction but can suffer from sagging if the blend is heavily on the polyester end of the scale. A new kind of process called densified polyester has been designed to alleviate this symptom. Wool futons make up a small percentage of the futon market. These futons offer excellent performance in terms of weight and support but don’t fare so well on flexibility and price. However, an added bonus for both polyester and wool futons is that they are flame retardant, a great safety feature.