Hi pix530,
[quote]We plan to buy new twin bed for our girl. She is 3 and weight about 40lbs now.
Not sure about firmness - mostly cause I read firm is required. But I dont want too firm for her due to her weight.[/quote]
Everything will tend to feel “firm” for younger children, as they don’t have as much mass. There’s some good information about choosing a mattress for a child in this post, and there’s more information about firmness guidelines for children in this post. Outside of the toddler range, a “medium to medium-firm” surface comfort is generally advisable. Of course, there are not “exact” recommendations, as there is of course no single firmness that is best for all children or all people, and different manufacturers will have different definitions of different firmnesses.
[quote]And thickness - best configuration would be 6" medium base with 3" super soft topper?
I also consider 1 layer 6" or 8" (soft or medium)? It will be 100% natural dunlop (aprico latex)[/quote]
The thickness of a mattress is just a side effect of the design and by itself isn’t particularly meaningful because whether a thicker or thinner mattress would be better or worse for any particular person will depend on the specifics of the materials (type, firmness, etc.) and on all the other layers in the mattress. Thickness is only one of many specs that are used to make different mattresses that perform and feel differently and that makes a mattress suitable for one person and not another. There is more about the effect of thickness in post #14 here. Having a core with a separate topper piece would give you more flexibility to create a slightly softer surface comfort (and the ability to customize down the road), but generally accepted guidelines would tend to lean more toward a more “medium” surface comfort for a growing child versus a “super soft”. As you’re considering latex, you would be using a good quality and durable material.
Phoenix