The firmness of the foam depends on its density. It is of poor quality between 16 and 20 kilograms per cubic meter (kg / m3), of mediocre quality up to 24 kg / m3, then correct between 25 and 35 kg / m3. Beyond that, the so-called “high resilience” foam has very good qualities of elasticity and comfort. The principle of zoning of the cells allows to vary the resilience according to the support zones (flexible for the feet and the head, firm for the pelvis) in order to keep the body perfectly horizontal.

Too low a density means that there is not enough material in the heart of the mattress. Because of the weight of the body, the heat and the humidity evacuated each night, a mattress too thin collapses quickly. It can be hard and give the impression that it will last, but it will not last. However, for small budgets, polyether foam whose density is between 16 and 23 kg / m3 may be sufficient in the case of an extra mattress. Here are a few mattresses that will help you to understand the difference with tempurpedic reviews.

Synthetic latex mattresses

Latex is a plant-based material derived from the sap of plants such as rubber trees. As it may present quality discrepancies and sometimes trigger allergies, synthetic latex manufacturing processes have been developed and are now the most widely used. This material is hypoallergenic and ensures very good aeration because it is extremely porous.

Spring mattresses

Spring mattresses offer the greatest ventilation and the most “dynamic” welcome. They are therefore better suited, a priori, to corpulent people and those who sweat a lot at night. It remains to be decided between the different systems. The diameter of the wire used and the number of springs – from 500 to 800 for a double bed – determine the firmness of the mattress.

Do bed frame matters?

There are two main types of bedsteads, springs and slats. The first consists of springs attached to a wooden frame. It is only suitable for mattresses springs. If you put a mattress foam or latex, it will sink quickly. Slatted bed base is suitable for all types of mattresses (except low quality spring mattresses). This is the most common model. It provides stronger support and lasts longer.