How To Fix A Sagging Mattress With Plywood

How To Fix A Sagging Mattress With Plywood?

A sagging mattress robs you a night of quality sleep and becomes a source of many problems like headaches, backaches, and so on. At this point, most people resort to replacing the old, sagging mattress with a new one.

Before spending money on that new mattress, you’d want to try and fix your old mattress to fix the sagging and make it feel like it’s brand new. How you do that? It’s simple; you just need a piece of plywood.

Find below our step-by-step guide on how to get rid of sags in your mattress with plywood.

Step by step guide for fixing sagging mattress with plywood:

fixing sagging mattress with plywood

Step 1. Determine what type of mattress you have.

The first step involves determining the type of mattress you have (the one you want to fix sags for). This step is crucial because using plywood to fix mattress sags doesn’t work with all types of mattresses. If you own an air, innerspring, or waterbed mattress, you should forget this method as you won’t achieve effective results.


Step 2. Measure the depth of your mattress sag

After establishing you have the right kind of mattress, you can then go ahead and measure the depth of sag on it to help you determine the ideal thickness you’ll need to repair. For this step, you can simply use a tape measure and yardstick positioned in a perpendicular manner.

Step 3. Put the plywood in place

Finally, you’ll need to cut the plywood and put it in place to fix the sag. Use a saw to cut the plywood, ensuring you cut it such that it’s smaller than the dimensions of the bed and mattress by around one inch. Place the piece of plywood between the mattress and the spring box. If your bed features a slate base, lay the plywood sheet on the slats and then place the mattress on top.

Fixing mattress sags

Bonus step: Fixing sagging due to frequent use

If sagging has occurred in a specific area of your mattress due to frequent use, say on the middle area, you can also fix it using plywood. In this case, you cut a sheet of plywood that matches the shape and size of the sagging spot. Next, place it under the mattress in the soft area to help push up your mattress and make it feel firmer like the other sag-free areas.

Is plywood an effective way of fixing mattress sags?

The plywood method has been used countless times by homeowners to fix the issue of sagging mattresses. It’s an effective method that will offer a temporary solution to this problem.

If the problem with your mattress is a lack of support, placing the plywood under the bed will help form a firmer base that supports the mattress and keeps it from sagging.

plywood an effective way of fixing mattress sags

If you have an older mattress, the plywood will act as a temporary solution for sagging by pushing up the problem area to make it feel firmer and feel like the rest of your mattress.

Advantages of using plywood

The top advantage of using plywood is that it’s a cost-effective solution for sagging mattresses.  You can easily get a sizeable piece of plywood. Not to forget, it works wonders to add firmness to your old, sagging mattress. This way, it will save you from having to invest in a brand new mattress.

Advantages of using plywood

Another benefit of using this method is that it’s a super-easy DIY process. As you might have seen from the simple to follow steps above, you can easily install the plywood on your bed without requiring an extra hand.

See also: Best Mattress for Graco Pack. n Play, Best Mattress for Murphy Bed, Best Mattresses for College Students

Disadvantages of using plywood

One of the main drawbacks of using plywood for sagging mattresses is the risk of mildew growth. Because the bottom of your mattress rests flat against the piece of plywood, it will limit air circulation around it, increasing the possibility of growth of mildew on the bottom of the mattress.

This is especially true if you reside in areas with a humid climate. Mildew can ruin your mattress and send you back to the stores for a new one.

Disadvantages of using plywood

However, you can fix this by periodically inspecting your plywood for the growth of mold and mildew, and fixing it as fast as it starts to form.

Using plywood isn’t a permanent solution for sagging. It will only stand in for a while, and after some time, you’ll notice your mattress going back to becoming uncomfortable again. Eventually, you’ll need to go for a long-term solution like buying a box spring or a brand new mattress.


If you don’t want to spend money on a brand new mattress, plywood will offer you a cost-effective and quick solution for the sagging mattress. The method is easy DIY and will help you easily fix the sags to make your mattress feel as comfy as new. Just follow the easy steps we have outlined for you in this guide, and you’ll have a sag-free mattress that lets you catch the Zzzs faster every time you get into your bed.

Leave a Comment

Your email address will not be published.