Dense? Firm? It’s not Either/Or

Caliber Yacht Photo

Caliber Yacht Photo

When our boat was delivered to us in 2004, we looked forward to sleeping aboard. The cushions in our main berth were more comfortable than our mattress at home. When we outfitted the boat we added a memory foam pad over the upholstered cushions and things got even better.  For four years we slept aboard on weekends and for some longer cruises between April and December. In 2008-9 we slept aboard from November to May with breaks for return visits to Virginia. Since October 2011, except for road trips, we’ve slept aboard full time. The cushions have developed a terrain. Our backs and necks have responded unfavorably.

We started pricing custom mattresses — $900 to $1500 — well, OK, it is our backs and necks we are talking about. But how do we know we are going to like a custom mattress? We know we liked the foam when it was  new and uniformly dense and firm.* After getting the foam specs from our ever cooperative builder (we are talking nine years after the sale) we found we could replace the foam for about $300. This means we could do this 3-5 times (spanning 9-15 years) and break even on a custom mattress.

So we found a place online that sells the foam we are interested in and can ship direct.

*”What are density and firmness? Is there a difference? Density and firmness refer to two different characteristics of foam.

Density is measured by taking a solid cube of foam, sized 12″ x 12″ x 12″, and weighing it in pounds. The denser the cube, the greater the likelihood that the particular foam is of higher quality, making it more resilient and durable. This is true only if the foam is not filled or “loaded” with additives that just increase the weight of the foam.

Firmness is measured by Indentation Load Deflection, or ILD. This is done by taking a cut of foam no smaller than 24″ x 24″ x 4″ and compressing it 1 inch, a 25 percent compression test, with a 50 square inch circular foot , measuring in pounds the force needed to compress the foam. The force needed is stated in a number reflecting the number of pounds needed to compress the foam 1 inch. The greater the number, the firmer the foam and the lower the number, the softer the foam.”


2 responses to “Dense? Firm? It’s not Either/Or

  1. moondance38

    We added a layer of memory foam to the vberth cushions. I think it was 1″ memory foam laminated to 4″ foam. Very comfy!

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