Memory Foam Mattresses

Memory foam and latex foam mattresses have some perks but aren't for everyone

Unlike innerspring mattresses, foam mattresses do not use springs to provide support. Instead, a foam mattress will mold itself to your frame in response to your body weight, providing good pressure relief and support. The two basic types of foam mattresses are viscoelastic (commonly called memory foam) and latex.

Memory foam is made from polyurethane, but it has a different structure than the lightweight foam commonly used as padding in innerspring mattresses. Memory foam is less springy and retains an impression longer, "remembering" the shape of your body. Many people enjoy the way memory foam cradles the body. According to survey results at SleepLikeTheDead.com, 81 percent of owners are satisfied with their memory-foam mattresses -- a slightly higher percentage than for other mattress type. However, others find sleeping on this type of mattress uncomfortable; Choice magazine reports that some people compare it to "sleeping on wet sand." The way the mattress conforms to the body also makes it harder to get up or change positions during sleep, especially for heavy people. This may pose a problem for some people, as small movements during sleep can be important for spine health. However, physical therapist Roger Herr notes in an interview at WebMD.com that body-hugging memory foam can be a good choice for "people with joint sensitivity due to arthritis or other conditions."

Another quirk of memory foam is the way it responds to changes in temperature. Memory foam changes its shape in response to the heat of the body, as well as its weight. This means that a viscoelastic mattress may feel hard in cold weather, although it will gradually soften up as it warms from body contact. Reviewers also note that memory foam tends to reduce air circulation around the body, creating a sensation of warmth that's nice in the winter but can feel too hot in the summer. Also, some owners report that their new viscoelastic mattresses release a strange chemical smell for up to a couple of weeks, a phenomenon known as offgassing. The odor goes away eventually, but some find it difficult to sleep with. The website MemoryFoamMattress.org notes that airing out the room or keeping a dish of vinegar on the nightstand can help dissipate the smell more quickly.

Latex foam is made from natural rubber or a synthetic version of the same compound. It can be a good choice for allergy- and asthma-prone people since it is resistant to mold and dust mites. However, latex itself can provoke allergic reactions in sensitive individuals. Latex is also breathable, keeping the sleeper warmer in the winter and cooler in the summer. Unlike memory foam, latex foam isn't affected by temperature, so it won't soften up in response to body heat and won't feel firmer in cold weather. It also doesn't mold itself as tightly to the body as memory foam, so it's easier to move around in bed. Latex doesn't offgas the way memory foam does, but it, too, can have a new-mattress smell that some owners describe as weird.

Foam mattresses are more expensive than innerspring mattresses, but they are also very durable; both viscoelastic and latex foam mattresses can last up to 20 years. Another advantage of foam mattresses is that they transmit motion less than innersprings, making them good choices for shared sleeping (especially if one person tosses and turns more than the other). However, foam mattresses aren't for everyone. We found many comments from owners who say they had to get used to sleeping on one. It's definitely wise to take a test nap on a foam mattress before you buy. If you don't like one brand, don't give up on foam altogether; different brands of foam mattresses can vary considerably in density, firmness and overall feel.

If you think you'd like a foam mattress but don't want to spend so much, one alternative is a foam mattress pad that you can lay on top of your current mattress. Tempur-Pedic sells a 3-inch-thick mattress overlay (*Est. $890, queen size), and Bergad offers Isoform viscoelastic pads (*Est. $130 to $260, queen size) from 2 inches to 4 inches thick. The nice thing about a mattress pad is that it can easily be replaced when it wears out for much less than a complete mattress. However, the editors of Which? magazine caution that some foam toppers can cost just as much as a new mattress, and they won't do anything to improve the support of an old mattress that's started to sag. For more information, see our report on mattress toppers.

Choices in memory foam mattresses

Memory foam mattresses vary in quality. Viscoelastic foam is graded according to several characteristics, including density, measured in pounds per square foot; indentation load deflection (ILD) rating, a measure of how compressible the material is; tensile strength and resilience. Trying to keep track of all these characteristics can be confusing, but in the end, it probably doesn't matter. As Herr points out, "looking at a mattress on paper, numbers, etc., does not guarantee a good night's sleep." The true bottom line is how comfortable it feels, and the only way to determine that is to test it out in person.

The best-known brand of memory foam mattresses is Tempur-Pedic. Many owners are very happy with this brand; survey results at SleepLikeTheDead.com indicate that 80 percent of Tempur-Pedic owners are satisfied with their mattresses. Another survey shows that 60 percent of Tempur-Pedic buyers say they would definitely buy this brand again -- a higher percentage than reported for any other mattress brand, regardless of type.

However, Tempur-Pedic mattresses also receive more mixed reviews in our sources than any other mattress brand. At Epinions.com, there are more than 75 reviews that give Tempur-Pedic beds a perfect 5 stars out of 5, describing them as incredibly comfortable and supportive. However, more than twice as many owners give Tempur-Pedic the minimum rating of 1 star, saying the mattress is hot, painful, foul-smelling and overpriced. (Some of the more colorful reviews compared the feel of this mattress to sleeping in quicksand, wet cement and hot lava.) We also read one professional study in which nearly half the testers liked the way Tempur-Pedic molds itself to the body, but more than a third found it uncomfortable. This appears to be a problem with Tempur-Pedic beds in particular, rather than memory foam in general; some testers who found the Tempur-Pedic mattress uncomfortable didn't have the same problems with the Sealy Comfort Series Blue Lake Firm (*Est. $2,120).

One obvious drawback to a Tempur-Pedic mattress is price. A queen-size Tempur-Pedic ClassicBed costs about $1,700, not including the box spring or other bed base. That's about four times as much as a basic innerspring mattress. Other manufacturers make less expensive foam mattresses that compete with Tempur-Pedic. The most notable of these is Bergad, which makes the Isoform line of foam mattresses (*Est. $800, queen size), Bergad Isoform beds receive more than 125 reviews on Epinions.com, with an average rating of 4 stars out of 5. We saw several reviews saying Isoform beds are as comfortable as -- or more comfortable than -- Tempur-Pedic mattresses. At SleepLikeTheDead.com, Bergad Isoform mattresses receive an owner-satisfaction rating of 80 percent, exactly the same as Tempur-Pedic mattresses.

Unlike Tempur-Pedic mattresses, which are sold in stores, Isoform mattresses are only available online. This means you can't test an Isoform bed prior to purchase, although both manufacturers offer a 90-day trial period. If you decide you don't like the mattress, you can return it to the company and pay only shipping charges (which vary according to where you live and the weight of your mattress). However, we did read several complaints at Epinions.com about Bergad's return service. Some owners describe problems getting the mattress back to the manufacturer, and others report delays in receiving their refunds. Bergad also seems to have more problems with durability than Tempur-Pedic. According to SleepLikeTheDead.com, 15 percent of Isoform owners report that their mattresses began to sag within three years, compared with only 10 percent of Tempur-Pedic owners.

Other manufacturers make memory foam mattresses that also receive excellent ratings from owners. SleepLikeTheDead.com reports the same owner-satisfaction levels for Bodipedic, Comfort Dreams, Night Therapy and Spa Sensations brands. Some of the major brands of innerspring mattresses, including Sealy and Simmons, have also begun to offer some options in memory foam. Sealy includes memory foam mattresses in its Comfort Series (*Est. $700, queen-size mattress set), and its higher-end Embody line (*Est. $2,000 and up for a queen set). Simmons offers the ComforPedic Collection (*Est. $4,000 and up, queen-size mattress set) and the lower-priced ComforPedic Loft Collection (*Est. $1,750 and up, queen-size mattress set).

Choices in latex foam mattresses

Latex foam mattresses are nearly as popular with users as memory foam ones. SleepLikeTheDead.com reports that 78 percent of owners are satisfied with their latex foam mattresses. Latex foam mattresses can be quite expensive, but they don't have to be. SleepLikeTheDead.com estimates the typical price range for latex mattresses is anywhere from $550 to $3,700. Memory foam, by contrast, runs anywhere from $400 to $6,300, and innerspring mattresses range from $600 to $9,500. Manufacturers often charge more for Talalay latex, which is made using a new production process that makes it softer and lighter than traditional Dunlop latex. However, there is no evidence that Talalay latex mattresses are either more comfortable or more durable.

When comparing latex mattresses, construction is more important than the type of foam itself. The editors of Choice magazine recommend looking for a latex mattress with a firm inner layer and softer foam on top, so you can feel cushioned but not completely engulfed. They also say that you should look at a cross-section of the mattress to see how big the perforations in the foam are. Holes of at least 1 centimeter (0.4 inches) will provide better airflow, so the mattress won't feel too hot.

Like memory foam, latex foam is available from many manufacturers who are better known for innersprings. Sealy makes latex mattresses both as part of its standard Sealy Brand line (*Est. $1,000 and up for a queen set) and its high-end Embody by Sealy line (*Est. $2,000 and up for a queen set). Serta produces the Vera Wang by Serta line (*Est. $3,000 for a queen set). However, we did not find a significant number of user reviews for either of these brands.

Eco-conscious buyers may want to consider the OMI OrganicPedic line of latex mattresses, which are arguably the most environmentally friendly mattresses available today. Each mattress is hand-crafted in a chemical-free factory from organic materials. In 2009, New York House magazine awarded the OrganicPedic Terra mattress (*Est. $5,000, queen size) its Innovative Green Design award in the bedding category. OrganicPedic mattresses also get a thumbs-up from Sarah Bernard of New York magazine, who tested 100 mattresses of various types in 2009. Bernard names the OMI OrganicPedic David (discontinued) as her favorite overall, though she notes that most of the latex mattresses she tried felt fairly similar.

If the OMI OrganicPedic is out of your price range, Bernard also likes the slim (7 inches thick) Ikea Sultan Erfjord (*Est. $900, queen size). This mattress is 85 percent natural latex and 15 percent synthetic. While not quite as green a product as OMI's offering, Ikea's mattress is made with sustainably produced cotton and other natural materials and, like other latex mattresses, is biodegradable. It also receives a favorable review from the editors at CasaSugar.com, who name it one of the three best green mattresses. SleepLikeTheDead.com reports that more than four out of five owners of Ikea latex mattresses (including the Sultan Erfjord) are satisfied with them.