Mattress Construction

Some day, sooner or later, you’re going to purchase a new mattress and foundation.  Maybe even more than one set.  Before you go shopping, we want to lay it all out for you and explain the consumer benefits of innerspring sets.  We want you to be a well-informed consumer and wise shopper.  We want you to choose a bedding set that best suits your needs, comfort and support requirements, and helps you rest comfortably.

We have no doubt, based on generations of manufacturing, testing, and research and development, that an innerspring mattress, with matching foundation, is the optimum choice for proper sleep support and unsurpassed comfort and durability.  This fact is emphasized by the millions of innerspring sets in use throughout the world today, providing restful sleep for only pennies per night (night after night, year after year).

Innerspring Composition

How can a few pounds of steel wire evolve into such a comfortable surface?  Basically, it translates into many small parts working together as a whole.  The hundreds of machine formed coils are held together in rows by lacing helicals (much like the spirals you remember from school notebooks) through the tops and bottoms of each coil.  A heavy gauge border rod makes the outer, rectangular perimeters (upper and lower), to which the helicals and outermost coils are either clipped or helically attached.  All together, this is a basic innerspring design, and is the heart of the finished mattress.


After the innerspring units are assembled, they are tempered by heat or electricity to assure that all of the formed wire retains its shape even after years of use.  Tempering removes the stresses set up during the manufacturing process.  From this point, the mattress manufacturer has the option of adding enhanced support to the borders, perimeters, inner zones and building-up the comfort layers.

The coils used to make these innersprings can take on a variety of designs, depending on the desired support and price point.  You may have heard of a mattress “coil count”.  This is the number of individual coils that make up a queen bed size.  Generally, the higher the coil count, the better the support and comfort for your body.  The shape of the coil determines its performance.  There are five basic coil designs:  (1.) Bonnell, (2.) Offset, (3.) Open Offset, (4) Marshall, and (5.) Continuous.

The Bonnell coil is one of the most widely used in the mattress industry.  It has an “hourglass” shape and is cylindrical at the top and bottom, tapering towards the middle.  The Offset coil is a less tapered version with squared-off heads that “hinge” when helically laced together.  The Open Offset coil is unknotted, its shape a modified version of the Offset coil.  Marshall coils are barrel-shaped coils enclosed, each in a separate flexible fabric pocket.  The pockets are all attached to the pockets surrounding them.  The Continuous coil consists of entire rows of coils formed from a single strand of wire.

The History of Bedding

Mankind has always sought a better surface upon which to sleep.  From the dawn of history, and for thousands of years thereafter, these surfaces were made up of grasses, leaves, twigs, furs, Spanish moss, cornhusks or anything at hand that was softer than the ground.  Later, in the late nineteenth and early twentieth centuries, mattresses became manufactured items.  These sleep products were filled with horsehair, feathers or cotton and were held in shape by an outer cotton fabric covering, or ticking, usually sporting a striped design.

During the late nineteenth century the steel spring coil bed, held together with a border rod, was invented and patented.  The bedspring offered a new dimension in comfort that hadn’t existed before.  Now there was an action surface upon which to place those primitive mattresses.  The two together offered the finest sleeping surface discovered to that time.

Further development of the bedspring resulted in a modern boxspring mounted on wood slats and covered to match the innerspring mattress.  Today the boxspring has been replaced by the rigid foundation (usually made of all wood or rigid metal stapled onto a wood frame base) and is designed as a working partner with the innerspring mattress.  Rigid foundations, as well as mattresses, enjoy a versatility of design characteristics that enhance the comfort and life of the bedding set.  You’ll receive the greatest sleeping comfort when you buy bedding sets that have been manufactured with this in mind.

Today’s Choices in Bedding

When shopping for a new bedding set you’ll find that there are many options available for your consideration.  Four basic categories include:  (1.) Innerspring, (2.) Foam, (3.) Waterbeds, and (4.) Airbeds.  The majority of the world prefers the innerspring design.

Innerspring Bedding

Innerspring bedding set consists of an innerspring mattress and matching foundation unit.  This combination out performs all other types of bedding from the standpoints of comfort, support and durability.  Innerspring units are constructed of hundreds of spring wire coils of various gauges, depending on the design.  The gauge relates to the wire thickness.  The lower the number, the heavier the wire.

Innerspring bedding has many advantages.  For instance, the mattress and foundation have free air circulation throughout.  There is no heat buildup and the air passing through it constantly refreshes the sleep set.

Innersprings buoy up the body.  The gentle upward support of an innerspring allows the body to relax completely, resulting in deep, restful sleep.  With active, buoyant support where it’s needed most, the spine remains relaxed.  No “hammock curves” or “bottoming out.”

Innersprings conform to body movement.  The hundreds of steel wire springs that go into each mattress move as the body moves yet maintain even support as they cushion.  Press down on an innerspring mattress.  You’ll note the give-and-take action as the coils readily adjust to your contour and movement.  The more weight, or pressure, exerted, the greater the coil response.  No other sleeping surface offers this unique “reserve support” that allows every body – from lightweights to heavyweights – to receive equal comfort from the same bed.  This controlled resiliency makes innersprings the leading choice for most buyers.

Mattress Sizes

Bedding sets are available in a variety of sizes because people come in a variety of sizes and have different sleeping requirements.  Making sure your bed fits properly is an all too often overlooked practice by a number of people.  Most of us would never attempt to wear a pair of shoes that were two or three sizes too small, but those same people might sleep eight or more hours every night in a bed that just doesn’t fit them.

For many years the standard bedding size for two people was the “double” – also known as “full” size.  This is truly old-fashioned sleeping.  In fact, two average sized adults in a full size bed only have about 26.5” of sleeping width per person.  That’s the same amount of space they probably had in their cribs as infants.  Furthermore, the 74” length is too short for anyone taller than 5’6”.  A good rule of thumb is to allow about 9” for pillow space.

The following is a listing of today’s most popular mattress standard sizes:
Size                          Width       Length
Twin                            38”             74”
Twin X-Long             38”             80”
Full                               53”            74”
Queen                          60”            80”
King / Eastern King  76”             80”
California King          72”              84”

Two average size adults should have at least the 60” width and the 80” length of a Queen size sleep set.  For those who have the bedroom space, a King size sleep set would be recommended.  A room as small as 12’ x 14’ can comfortably house a King set with room for other necessary bedroom furnishings.  So, don’t discount the possibility of stepping up to the best possible bed you can acquire.  Remember, almost one third of an average human life is spent sleeping.  Your quality of sleep directly affects your health and the quality of your sleep surface directly affects your sleep.

To date, there are more than 27 million innerspring sleep sets that are more than sixteen years old.  That means that these mattresses, no matter what their quality level at purchase, are not providing the proper support and comfort needed for restful sleep.  Many of these mattresses have been passed from one family member to another.  Sleep sets should never be used past their life expectancy, usually eight to ten years.

It makes little sense that we replace our $20,000 and up vehicles after 3 to 5 years, buy our kids $100 shoes every year but attempt to use our mattress until it falls apart at the seams.  Passing your worn out mattress to your kids is not acting in their best interest.  In fact, you are sacrificing their health.

Foundation Composition

The foundation begins as individual tempered steel coils or modules and other components that are assembled into finished products to meet the needs of bedding manufacturers.  The better foundations have a grid top that covers the entire top surface.  One of the best grids contains wire that is welded at all intersections and wrapped around and welded at the border rod.  Thus, the grid becomes one piece.  The grid is then attached positively to the coils and/or modules, with the border rod on top and coils and/or modules attached to a substantial wood frame at the bottom.  The result is a one-piece rigid metal and wood foundation construction ready for a bedding manufacturer to finish.  Some foundations are made of a substantial wood frame at the bottom, sides and top with a heavy corrugated cardboard surface, and then finished with ticking and dust cover protection underneath.  Today’s foundations are rigid.

Choosing the Finished Sleep Set

Now that you are a well-informed consumer with regard to the innerspring and foundation units, you are faced with an infinite number of comfort layer options and support enhancements.  The endless possibilities of combinations make comparing models, especially between brands, nearly impossible.  But, if you understand the basic materials used, you will better understand the features and benefits that enhance the better designs.

Number one, the only effective way to try out a mattress is to “try it on” or “test drive” it.  Lie down on it.  Maybe even curl up like you would at home.  Don’t just push your knee into the surface, don’t lie half on the mattress with legs dangling off the mattress.  Your entire body should be on the mattress to ensure your weight is distributed properly so that you can feel exactly what the mattress will feel like when you’re sleeping.  The point is to get a real feel for the mattress. A salesperson can only explain how the mattress set is intended to work and feel.  Let your body tell you if it’s the right choice for you.

A basic innerspring mattress consists of the coil unit, layered with some type of insulator to help prevent the comfort layers from sinking into or between the coils over time.  Most are heavy fiber, felt layers.  Additionally, some manufacturers use nylon netting or similar designs to further protect from layer breakdown.  Above the insulator, various foams, fibers and cotton batting are layered to create different mattress cushioning effects.  The quality and amount of these layers usually increase with the price tag.  All of these materials are encased with a quilted ticking.  This is the layer you see.  Ticking comes in almost every color and pattern imaginable.  Some are nearly flat, while others offer a plush finish.  Pillowtops, often a higher end feature, offer the plushest finish yet with a big pillow of soft foam or fibers attached to the mattress top.  However, be careful not to judge the mattress based on its exterior alone.  Ask the salesperson about what’s inside, and again, try it out for yourself.

Childhood is the formative developmental period when young bodies are growing and need the best support you can afford.  An unsound mattress is not conducive to the development of healthy young bodies.  Each year, you should examine your families’ sleep sets.  Assess their condition and allow ample time to shop around for a replacement sleep set when the time comes.  As an informed consumer, you will be able to ask knowledgeable questions, understand what features you desire, and be able to sleep well knowing the sleep set you choose is the best choice for you and your family.

The Industry Leader

Leggett & Platt, Incorporated is the world’s leading manufacturer of innerspring and boxspring units, with manufacturing facilities throughout North America, in South America and Europe.  Leggett’s quality, dependability, and continual research and development is trusted and respected among today’s mattress manufacturers worldwide.  We are proud of our long heritage in the industry, and strive to provide the finest, most innovative bedding components available.

Leggett & Platt
“All About Bedding”
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