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Many of us love plush beds that feel like a cloud.
But when a mattress is too soft, it kills your back. And your mood.
So, if that’s what you are dealing with right now, let me show you how to make a mattress firmer.
Key takeaways
- You can make a mattress firmer by adding a mattress topper to it, adjusting the layers to put the firm side up, or creating a firm mattress foundation for your bed.
- If your bed is old, it might just be a good idea to replace it with a new, firmer bed. When I want to buy a new mattress, I usually try to choose a medium-firm mattress that will satisfy my need for support.
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#2 Take the Mattress Outside
Such factors as mildew or mold can make your mattress too soft. Like when you washed it, didn’t let it dry completely and started using the bed, the dampness inside turns into mold and mildew. And when there’s too much moisture, the texture of the mattress can get compromised.
That’s why simply letting your bed dry can make it feel firmer. You can take the mattress outside to the fresh air and even leave it in the sun.
“If you have a memory foam mattress, it’s better to leave it in the shadow. Too much heat and direct sunlight can actually damage the material.”
#3 Create a Firm Foundation for Your Bed
To make the most of your mattress, you need to use it with a compatible bed base.
You thought this rule applies only to mattress types?
Wrong!
You can easily make your mattress feel firmer if you adjust the bed frame, and here are some options for you:
- Reinforce your bed frame with a plywood sheet. Use the plywood that is 0.5-1” thick: this is enough to create a sturdy base under your mattress and scale its firmness up for a bit. This method is cheap and works with almost any mattress up to very old. You might want to cover the plywood with cardboard sheets, though, to absorb the moisture and prevent mold growth inside your mattress.
- Add a bunkie board. Bed frames with widely spaced slats can cause your mattress to sag and feel softer than it really is. Adding a bunkie board creates an additional level of support without decreasing air circulation and helps fix a sagging mattress, so this method is especially good for old memory foam beds.
Also Read: Plush vs Firm Mattress
Check the condition of your bed frame. If your foundation is old and flimsy, it also may fail to deliver you proper support. In this case, it’s better to replace it. Opt for the sturdy bed base with wide wooden slats or mesh design: they will ensure minimal sagging and even support.

Finally, you can just give up the bed base completely and place your mattress directly on the floor. However, it’s better to place a rug under it to avoid collecting moisture and debris.
#4 Set the Right Temperature
If you use a memory foam mattress, the problem could be in the temperature. You see, when the room is too warm, memory foam may loosen its texture and become softer. By simply adjusting your thermostat and making the room cooler, you can make a memory foam mattress firmer. Plus, this can even help you sleep better.
#5 Replace Some Layers
Depending on how old your bed is, sometimes the only way to fix a sagging mattress is to replace some of its layers. This can help you save some money since you don’t really have to buy a new bed. Simply unzip the encasement and throw the old, worn layers away.
Sometimes, a bed cannot be saved, especially when it’s too old and saggy, so your only option may be to buy a new mattress rather than trying to make the old one firmer.
Some companies sell layers for their mattresses separately, so don’t worry, you will have something to fill your bed with. You can also try replacing some comfort layers with a thin topper.
#6 Use a Mattress Topper

This is definitely the easiest and the most effective way to make a mattress firmer. A good topper can change the way your bed feels in seconds. You just need to get the right one. (if you are a side sleeper, here are the best mattress toppers for side sleepers)
Thankfully, there are tons of options to choose from. The most popular materials for mattress toppers are foam (memory or polyurethane) and latex. Some manufacturers offer cooling toppers, which are usually infused with charcoal (sometimes green tea extract) or have a thin gel layer on the top to draw the heat away from your body. Mattress toppers also come in different thickness options. So, even if your bed feels terrible, an extra thick firm topper might save the day.
Feel free to experiment with your soft bed. You might want to try a couple of toppers or adding a mattress pad.
Now, a little bit more on the materials, as they have specific properties. Foam toppers (both memory and polyurethane foam) are great for contouring and pressure relief. They may also help with motion isolation. Memory foam has that unique slow-hugging feel many sleepers enjoy. But it may make you feel stuck, especially if you are a heavier user and sink in deeper. Also, foam tends to sleep hot. Plus, there’s odor potential, which may be an issue for smell-sensitive people.
As for latex, such toppers offer bouncier support. Latex is cradling (but not as much as memory foam) and good for motion isolation (1). What’s great about this material is that it’s natural and safe. And odor potential is minimal. Besides, your new latex topper might only smell like rubber during the first day. After that, you don’t have to worry about chemical odors at all. Another great thing about latex is that it doesn’t sleep hot. At the same time, such toppers are pricier and unsuitable for people allergic to this material.
“Mind the difference between mattress toppers and pads. A pad is usually much thinner than a topper and has fiber filling in most cases.”
#8 Keep The Bedding Flat
Sometimes, your mattress can be too soft because of the soft cushiony bedding that you put on top of it. If you want to have a firmer mattress, consider keeping your bedding completely flat. I usually try to use only a mattress pad or a firm mattress topper on top of my bed and avoid using any extra pillows underneath my back (2).
#9 Use a Rubber Mat
If you have no other choice left to firm up a soft mattress, you can always use cheap yoga mats or similar rubber mats customized to fit your bed size to make your mattress firmer. It probably won’t be as effective as buying a mattress topper, but it will definitely make your mattress firmer. If needed, you can use a combination of several of them and adjust your mattress firmness.
Conclusion
Now that you know so many ways to adjust your mattress firmness or make it firmer, you can even combine these methods to come up with a final solid way to increase the firmness of your mattress. You can always add a mattress topper, keep your mattress foundation firm and sturdy, and avoid using plushy or uneven bedding. All these methods work well if you monitor exactly how firm you want your mattress to be. As long as you don’t make it extra firm and only enough to keep yourself supported, it should be good enough.
I hope this article has been helpful for you. If you have any thoughts or comments, be sure to let me know in the comments section.
Additional resources:
Best Extra Firm Mattresses You Can Find Today — Reviews and Buyer’s Guide
References:
- Fan-Zhe Low (March 2017). Effects of Mattress Material on Body Pressure Profiles in Different Sleeping Postures. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5310954/
- Duo Wai-Chi Wong (December 2021). Sleeping mattress determinants and evaluation: a biomechanical review and critique. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6348954/