10 Tips on How to Make a Mattress Firmer

When considering how to make a mattress firmer, it is also important to consider the type of mattress you are using. For example, an air mattress can be made firmer simply by pumping in more air, while a memory foam mattress might be soft because it is too warm. It helps to understand the factors involved in your mattress becoming too soft.

We are not discussing age here – most mattresses will get wear and get softer with age, although some of the tips below will work with an old, worn mattress. You may prefer to try some of these before purchasing a new mattress. Moisture is one factor involved in mattresses becoming softer, as is lack of proper care and maintenance. Temperature is another factor.

Some types of mattress, particularly memory foam mattresses, as mentioned earlier, become softer as the temperature rises in your bedroom. Here are 10 ways to make a mattress firmer, not all of which apply to all types of mattress. Not everybody agrees on the ideal level of hardness for a bed, and some of the tips below may work better for some than for others. They are presented in no particular order of preference, though the first five should likely be tried initially.

How Can You Firm Up a Mattress?

1. Keep the Bedding Smooth and Flat: Make sure you use a sheet of appropriate size for your mattress. Pull it tight from top to bottom and side to side, so that the sheet is applying some pressure to the mattress and is pulled flat over it. Doing that might firm up the bed enough for your liking. If not, a tight, flat sheet will at least make it more likely that some of the tips below will solve the problem for you.
2. Flip and Turn the Mattress: The most obvious solution would be to flip the mattress. Many types of mattress tend to sag when used continuously in the same position. If your mattress has become too soft over a period of time, then flipping it often solves the problem. Flip it over, so the top surface becomes the bottom, and then rotate it so the head of the mattress becomes the foot. People frequently find that this helps their mattress regain its old firmness – or close to it. Sometimes just flipping it, without rotating/turning it, solves the problem.

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3. Use a Hard Support: Your mattress can feel soft if it does not have sufficient support. If your mattress is lying on a box spring structure, or any other sprung surface, then it may not have enough support to promote firmness. If you place a sheet of 3/8” or more plywood or particle board between the box spring and the mattress, then your mattress will have more support and will feel firmer. If you do this, make sure the plywood is exactly the same width and length as the mattress. Too short will lead to an overhang while too large could lead to personal injury on the protruding wood. Make sure you sand the edges smooth and round the corners of the board to prevent damage to the mattress or yourself!
4. Place the Mattress on the Floor: If you prefer not to try a sheet of plywood immediately, then place the mattress on the floor. This may also remedy the situation. If you find that your mattress is firmer on the floor, then you can either leave it there, try the plywood solution above in the knowledge that it will work or construct a solid base to raise the mattress to your desired level.
5. Use a Mattress Topper: A soft mattress can often be made harder using a topper. There are various types of mattress topper, the most popular being a hard foam or, even better for some, a memory foam. Memory foams come in various levels of hardness, and you can choose one that suits your needs. Such toppers are no more than a few inches thick, usually 2” – 6”, offering the memory foam effect for those that like it. Alternatively, you can select a regular latex or polyurethane foam of appropriate firmness. Pads are thinner, filled with polyester or other material and are not as effective as toppers.
6. Check and Replace the Box Spring: A box spring mattress can easily lose its strength with prolonged use. This will provide less support for your mattress than it should, and your bed may be too soft for you sleep on. There are two ways to resolve this. The first is to purchase a new box spring. This will bring your bed back to its original condition, assuming your mattress is still in good shape. The other way is to use a hard support over the box spring structure as above.
7. Adjust the Bedroom Temperature: Higher temperatures generally lead to softer mattresses, while a colder environment tends to make them firmer. If your mattress feels more comfortable in the colder months than in summer, then setting your air conditioning to a lower temperature (or bedroom heating in winter) might cool the mattress sufficiently to meet your needs. This is particularly true of memory foam mattresses.
8. Replace Worn or Damaged Layers: Some mattresses are constructed in the form of multiple layers held within the cover. Some have a core support layer, and a comfort layer comprising an insulator, a middle layer and a quilted layer. If any of these are worn or damaged, that can affect the hardness of the mattress. You can replace any of these layers with a harder layer by opening the mattress, removing the damaged layer and replacing it.
9. Dampness, Mold and Mildew: Your mattress can become soft because of dampness and contamination with mold and mildew. If you dry out the mattress then the mold and mildew will go. Take the mattress out into the sun and let it dry out. This will not only firm up the mattress but kill off any bacteria and germs that are contaminating it. This is quite common with mattresses that been allowed to get damp. You can also pay for professional cleaning, but try this first – it can make a difference!
10. Purchase a New Mattress: If all of the above fail to make your mattress firmer, your next option is likely to invest in a new mattress. If your mattress is old, it is likely that modern mattress technology can offer you one that suits you perfectly. Modern memory foam mattresses offer a range of hardness options, each one providing you with proper support for your pressure points when lying in bed.

Were we to give any preference to these ways of how to make a mattress firmer, we suggest looking at tips #1 – #5 first. One of these is most likely to solve your problem, although the other 5 have also been known to be an effective solution to an over-soft bed or mattress. All mattresses have a finite life, and sometimes the only genuine solution is to buy a new mattress.