Bed slats are a vital part of your bed structure. It’s the direct support for you and your mattress, so you should consider the weight that needs to be supported and if the material can hold its form for an extended period. Plywood is an option many will consider when replacing the support slats for their bed.
You can replace bed slats with ¾-inch thick plywood. Some recommend making plywood slats 3 inches wide, spacing them 3 inches apart, and some suggest using the whole plywood sheet to place on top of the existing bed slats. Adding a support beam helps plywood support more weight.
Replacing bed slats is an easy project to tackle, even for beginner DIYers. This article will discuss ways to replace bed slats with plywood and prevent sagging and weight issues from using plywood material.
About Plywood and Its Use for Beds
What Is Plywood
Plywood contains many sheets of wood glued together with the wood grains rotated to create a thicker sheet. Because this is a type of engineered wood, the weight load it can handle will be smaller than if you were to use the typical lumber, such as a 2×4 in or 2×3 in stud. It’s vital to ensure the plywood is adequately supported to handle the weight.
Don’t confuse plywood with other engineered wood, such as MDF, OSB, and particle board, because they are not the same and are a weaker option for supporting weight.
Plywood for Mattress Support
There are two ways you can use plywood for mattress support. You can make plywood slats or use whole plywood sheets as a platform. Both options will be explained later in the article.
Either way, you’ll need to add proper support so that the plywood can hold the weight of the mattress and whoever is on the bed without issues of sagging or weakening.
Ensuring Your Plywood Supports the Weight
Higher-quality plywood with a middle support beam will ensure better support without issues of sagging or breaking. The thickness of plywood is also essential because there is more support from a ¾-inch sheet than from a ¼-inch sheet. So, using plywood no less than ¾ inch thick is recommended.
If you’ve ever had to move your mattress, you know it’s heavy. So, you should consider the mattress weight the plywood will be holding. The following is the weight according to mattress size:
- Twin: 40 to 45 lbs (18 to 20 kg)
- Twin XL: 43 to 48 lbs (20 to 22 kg)
- Full: 50 to 60 lbs (23 to 27 kg)
- Queen: 120 to 160 lbs (54 to 73 kg)
- King: 130 to 180 lbs (59 to 82 kg).
A sheet of ¾-inch plywood can hold 50 lbs before beginning to bow in the middle. This tendency to bow is why adding support is imperative, or the plywood may bow to the floor. So, if you’re considering using plywood to support your mattress, adding one or two 2×4 in support beams will be necessary.
Option 1: Using Whole Plywood Sheets
Some have suggested using a whole plywood sheet as a platform for your mattress instead of bed slats. But for bed sizes bigger than a twin XL, you will need two sheets of plywood cut to fit the bed.
Below are the dimensions for bed sizes to refer to when cutting the plywood to fit:
- Twin: 38 in W, 75 in L
- Twin XL: 38 in W, 80 in L
- Full (or double): 54 in W, 75in L
- Queen: 60 in W, 80 in L
- King: 76 in W, 80 in L
- California King: 72 in W, 84 in L
There are two ways to make a platform for your mattress by using whole plywood sheets:
- You can place them directly on the existing slats.
- You may create a support with 2×4 inches connected to the head and foot of the bed and place the sheets on the support beams.
It’s easier to lay them directly on the existing slats to get the desired support you’re looking for without adding additional support.
Using whole sheets for a mattress platform can create more firmness in the feel of your mattress comfort level.
The biggest pro to using whole sheets instead of creating slats out of plywood is it’s less work, especially if you’re placing them directly on the existing slats.
How to Make a Plywood Platform
Whether you’re placing the plywood directly over slats or you prefer to add support beams, cutting the plywood to fit your bed size will be the same.
To do this project, you’ll need the following materials and to complete the steps listed:
- Circular saw
- Tape measure
- Pencil
- Hammer and nails or hand drill and screws
- 2 Plywood sheets 4 ft x 8 ft, ¾ inch thick
- Sawhorses or something to support the plywood for cutting
- 2x4x10 in piece of lumber
The steps:
- Measure the width of your bed frame
- Cut the length of the two plywood sheets to fit your measured width
- Place one sheet on the frame against the headboard
- Measure the remaining gap for the second sheet to fit
- Cut the second sheet to fit and place it on the frame. If you put the plywood sheets on the slats, skip the remaining steps
- Cut the 2x4x10 in lumber to fit the length of the bed frame. This length is your beam that will support the plywood pieces and prevent bowing
- Now, you’ll create two support legs with the scrap 2×4 in lumber by measuring from the bottom of the plywood to the floor and cutting it into two pieces using that measurement
- Nail or screw one 2×4 in leg 12 inches from the headboard and place the other one 24 inches from the footboard on the 2×4 in beam you created
- Slide the beam under the plywood, center it, and secure the plywood to the beam with screws or nails
Option 2: Using Plywood for Bed Slats
If you want to replace your old or broken bed slats with plywood slats, there will be more work involved than using plywood as a platform. To create proper support, you’ll need to make several slats for your bed frame. For example, you will need approximately 20 slats for a queen-size bed.
The slats should be about 3 inches and 3 inches apart. Spacing the boards 3 inches apart allows for sturdier support to prevent sagging and weakness from the boards being strained from the weight. When you place the slats too far apart, more strain will be put on the plywood, causing weakness and sagging because there will be fewer boards to help carry the weight.
How to Make Plywood Bed Slats
It isn’t as difficult as you think compared to many other DIY projects. You’ll need a few tools to get complete make the bed slats.
The tools required for this project are as follows:
- Circular saw
- Tape measure
- Pencil
- 2 Plywood sheets 4 ft x 8 ft, ¾ inch thick
- Sawhorses or something to support the plywood for cutting
- 2x4x10 in lumber
The steps:
- Use the tape measure to measure the inside width of your frame where you will place the slats. This measurement will be the length of your slats.
- Place your plywood sheet on the sawhorse to mark your measurements for the length.
- Using the tape measure and pencil, mark the length measurement for the first slat starting at one end of the plywood sheet.
- Now measure 3 inches from the edge going inward for the width of the slat. Make several of those 3-inch marks for the length of the slat to make it easier to cut straight. If you have a long leveler or board, use it to connect your measurement marks to create an easy line to follow when cutting.
- After you have marked your first slat, use the circular saw to make your cuts, following the marks or lines you have created.
- Before making your other slats, you should always test the first one by placing it in your bed frame. This test prevents wasting time and materials if the first slat doesn’t fit as needed. If it’s a perfect fit, continue making your other slats the same as the first until you have made the number of required slats for your bed support.
- When you place the plywood slats on the frame, space them out about 3 inches apart to make the weight load more manageable for the plywood to support. Screwing the slats in place isn’t necessary but can be done to keep the slats in place if preferred.
- If the bed is wider than 4 ft, it would be ideal for securing a 2×4 in beam, as mentioned in the instructions above on making a plywood platform.
Final Thoughts
Replacing bed slats with plywood is an option to consider. As long as center beams support the plywood or you’re laying the sheets over existing slats, it will hold the weight without bowing and creating saggy areas in your mattress. Using whole plywood sheets as a platform for your bed may make the mattress’s comfort level more firm.
