The Base Foam Layer

The base foam is a critical part of your memory foam mattress. No matter how luxurious the memory foam top layer, cutting corners on the base layer will produce an unsupportive and uncomfortable bed.

There are a huge variety of foam base layers you could use. Most manufacturers use polyurethane foam in the base layer, so this discussion is limited to that product. I would be interested to hear from people who have used other foams, especially latex.

Be careful of exceptionally good deals – the foam could be low density, or a cheaper layered construction. We’re looking for one giant chunk of foam. If there is a foam supplier in your area, this is usually your best option.


This was discussed extensively in differences between memory foam, so I’ll keep it short here. Typically, high end memory foam beds will use 2.2 lb/cf polyurethane open-cell foam as the base layer.

Luckily enough, this is one of the most common foams used for basic foam mattresses! So, all we need to do is buy a foam mattress which meets or exceeds these specifications. Look for a minimum of 2.2 lb/cf, and a firmness rating of at least “medium”. This is the major load bearing part of the bed. The memory foam distributes the pressure evenly, but the base layer distributes the load to the bedframe. Without a quality base layer, the mattress will sink and sag – no good!

What I Did


I used a Sultan Fangebo foam mattress from IKEA. This mattress is a solid chunk of 3.5 lb/cf foam, and is found to be medium to firm by most reviewers. There’s just one problem – IKEA appears to have discontinued this model. The newer ones use cheaper foam in layers, which isn’t really what we’re looking for at all.

The good thing is that what we’re looking for is dead simple – a roughly 6″ thick layer of 2.2 lb/ft3 polyurethane foam cut to standard mattress sizes. Check out foam distributors online if you can’t find one in your area.

11 thoughts on “The Base Foam Layer

  1. Have anyone recently purchased a great base foam with the minimum specification recommended by Geoff? Can you share the manufacture info or the store info? Thank you so much.
    Excellent DIY column, Geoff. Thank you.

  2. has high quality base foam at fair prices, IMO. I purchased an 8″ thick slab of Lux High-Quality from them about 18 mos. ago and it hasn’t even begun to show signs of wear. It really is a superior product!

    It has a density of 2.8lbs/ft3 and is VERY firm.

    BTW, they make a slightly less firm but equally durable base foam: HD36, High-Quality.

    I’ve been very happy with my DIY foam mattress; any questions for me, drop an e-mail.

  3. Hi Geoff,

    Thanks for the great article. Do you know the dimensions for Fangebo mattresses by chance? I couldn’t find it on IKEA’s site since it’s discontinued. Thanks again!

    • Hi Jamie –

      I believe the Fangebo mattress is 6″ thick, and came in double, queen, and king sizes. I personally used the queen sized one (60″ by 80″).

    • Hi Patti – You could, but the major issue would be that an older mattress typically lacks the support necessary to fully take advantage of memory foam. If it is uniformly firm with no sagging at all it may be fine, but a sagging mattress will end up sagging even more with memory foam on top.

  4. Hi again, Geoff, I wrote a while back when I thought I would buy a Bobopedic. But after asking questions about the bed no one in Bob’s organization had answers for, I’m back to make-it-myself.

    I have 3 questions & suggestions from all are welcome.

    First, I’ll be putting the foam on my boxspring which is a good & stable one. How thick do you think the base layer would need to be?
    Also, do you think memory foams, like Isoform, that advertise being “more open than other foams” are actually cooler to sleep on as they say???
    Last, did you cover the memory foam with a particular type of cover? There seem to be a lot of brands of waterproof covers recommended for memory foam. Some also say they wick moisture so the mattress sleeps cooler. To wick or not to wick is my question. 🙂
    Thanks so much for your thoughts & for this site.

  5. My doctor suggested I change mattresses.
    My old one was a heavy antique.
    I wanted lighter foam and no springs.

    I tried 2 foam mattresses from Ikea: the Finvik and the Favang.
    Both were rated as firm and used High resilience foam.
    I found these to soft and too cushiony.
    When I opened the zippered cover, I saw that the foam inside wasn’t the same as the one in the store.
    I also saw that one had black stain on the foam.
    I took it back to the store.

    I decided to make my own mattress.

    I bought 6 inch foam slab (they call it a topper) from Sears. It is rated as Medium (32 IDL)
    I slept on this and it molds a bit to your body and it is firm.
    I needed a bit softer so I added 2 x 1 inch memory foam toppers bought at Wallmart and on top of that I put a convoluted foam pad.

    Note that I put a mattress pad on the Sears foam base slab to make it a bit firmer.
    I covered it all with an encasement to protect the foams from the body moisture or ceiling leaks.

    I’m still getting used to it.
    I may remove one layer.
    That is the nice thing about making your own mattress and not gluing it all together: you can tinker with the layers to adjust it to your liking.

  6. I would not suggest a water proof “ticking”/cover. A water proof cover will always sleep much hotter. Suggest a bamboo cover. and the foam from has a variety of mattress foam products.

    I am in the process of using a 2.5 nova gel foam for the top layer purchased from Costco $119.00 a 3″ memory foam 5lb density (from my 20 year old Temperpedic, plus 2.5 convoluted HD 36 foam $95.00, and a 3″ LUX HQ foam $123.00 layer for a total of 10” and a cost of less than 500.00. This I feel will duplicate the Temperpedic that I do not want to replace which would cost me about 4,200.00.

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