Peu connu sous ce terme générique et pourtant un élément de literie indispensable au confort, le sous matelas ne doit pas être confondu avec le sur-matelas (moelleux, ferme, en mousse ou à mémoire de forme, épaisseur variable, etc.), car il possède ses propres critères de sélection. Mais, avant même de parler des critères de choix et de qualité de ce type de produit (taille, prix, épaisseur, confort de sommeil, etc.), il nous parait plus judicieux de définir ce qu'est cet élément de literie pour mieux nous intéresser aux différents modèles existants. Car un sous matelas, c'est avant tout un type de technologie permettant de rajouter du confort au couchage.
Why use a mattress topper? What are its benefits for sleep? What are the recommendations for using this technology?
We answer all these questions in our guide to mattress pads.
The Definition of a Mattress Pad: Understanding Its Purpose
Etymologically speaking, the term “mattress topper” suggests that we’re talking about a material that goes between the mattress and the surface supporting it. If we consider an ordinary bed, we tend to picture a simple piece of foam inserted between the mattress and the box spring. But while this image isn’t entirely wrong, it’s incomplete, given the many possible uses for this bedding item.
A mattress pad is, in fact, what you place under a mattress. But according to this definition, a simple box spring would also be a mattress pad. To that, we would reply that yes, indeed, a box spring is an example of one, since its purpose is to prevent direct contact between the mattress and the floor. In fact, everyone releases moisture during the night (through perspiration or water vapor). This significant amount of moisture—an average of one liter per person per night—becomes trapped in the bedding (mattress cover, mattress, pillow, box spring, sheet, etc.) and must be allowed to escape to ensure the bedding remains hygienic.
Due to gravity, this water flows to the bottom of the bedding and ends up at the center of the mattress, where it continues to evaporate through the sides of the mattress or through the box spring. For these reasons, a box spring is an essential solution to this problem of moisture retention, and it is raised on legs to prevent constant contact with the floor and facilitate the escape of water vapor. This is also why all bedding brands recommend using a box spring. Beyond compromising the product’s quality and hygiene, moisture retention in bedding also affects your health.
The Purpose of a Mattress Pad
As we explained earlier, the primary function of a mattress pad is to allow water trapped inside the mattress to drain away. Of course, this should not come at the expense of the comfort we expect from our bedding or of the body’s need for healthy, restorative sleep. The box spring is the prime example of this. Note, moreover, that a mattress warranty often requires the purchase of a matching box spring so that the manufacturer can guarantee its product under optimal conditions of use. Good bedding is, above all, a cohesive system that includes both the mattress and the box spring.
- Le manque de fermeté ou de tonicité d'un matelas peut être partiellement compensé par l'adjonction d'un sous matelas entre le matelas et le sommier afin de compenser un ensemble insuffisamment ferme à votre goût ou ayant un effet "ressorts" désagréable. Ce produit se matérialise souvent sous la forme d'une planche alvéolée à la dimension du matelas pouvant être revêtue d'une fine mousse de garnissage. Attention, la présence des alvéoles est indispensable, car bien qu'un panneau de bois type OSB puisse obtenir le même effet sur la fermeté, vous perdrez dès lors les avantages de la ventilation de votre literie et aurez donc les mêmes effets que si votre matelas était posé au sol.
- Thermal regulation is another factor that this type of product can sometimes help compensate for. Some mattresses (especially foam ones) can affect sleep comfort because they have little thermal inertia, making them feel cold or hot depending on the season and room temperature. A mattress topper can (depending on its filling) increase or decrease the thermal inertia of your entire bed, depending on what needs to be addressed. The heat or cold of bedding is often one of the reasons for poor sleep quality.
- Sometimes the mattress “slides” a little on the box spring during the night, and you wake up with part of the mattress hanging off the edge and the unpleasant sensation of the box spring against your body. A mattress pad can help reduce or eliminate this sliding effect, ensuring that the entire setup stays in place.
- Another way to protect the box spring is to use a mattress pad that fits over it like a cover. A box spring is usually already protected by a muslin cover (upholstered box spring) against impacts and stains. However, the constant friction between the mattress and this muslin can quickly degrade the quality of the bedding—an inconvenience we’d rather avoid, given the high retail prices.
Finally, for unusual or so-called “makeshift” sleeping arrangements, using a mattress pad when a bed frame cannot be set up due to lack of space or practicality offers several advantages. For example, for adventurers sleeping in the forest—often on inflatable mattresses—a foam pad (which can be rolled up and attached to a backpack) protects the sleeping surface from thorns and brambles while breaking the thermal bridge caused by contact with the ground. Sleeping in unconventional places (boats, RVs, etc.) often leads to condensation, and using this type of solution (often made of cork or rot-resistant foam) helps create a sleeping surface that’s better protected against moisture.
The mattress pad: a technology almost as important as the mattress itself
As you can see, the mattress is still the primary factor determining the comfort of a bedding set. However, this comfort is closely tied to the use of a mattress support, which, nine times out of ten, turns out to be a box spring.
The primary role of a mattress pad is to wick away moisture from the bed after a night’s sleep, releasing it into the surrounding air to preserve the quality and durability of your bedding. This is key to keeping your bedding in good condition over the long term. Of course, certain materials—such as the natural latex used in Kipli mattresses—possess inherent qualities that promote this moisture-wicking effect.
Que votre matelas soit à ressorts compressés, en mousse à mémoire de forme, en latex naturel ou synthétique, aucun matelas ne peut rester à même le sol sous peine de se détériorer promptement. En effet, les matelas mal ventilés finissent par présenter des auréoles jaunâtres, des moisissures et parfois même une désagréable odeur à cause de la stagnation du matériau (faute de ne pas inverser la position du matelas régulièrement) et de leur mauvaise ventilation (absence d'un sous matelas adéquat).
So, to avoid this and ensure that your bedding remains consistent and comfortable, the mattress pad is an element you need to carefully consider when choosing a bed so that your (often costly) investment remains worthwhile in the long run.
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