Replace Bed Slats with Plywood: 11 Step Helpful Guide & Tips

Manufacturers are not exactly known for building strong wood bed frames that last decades, or even a few months in some cases. And they seem to think everyone in America weighs 120 lbs like in Asia.

So they build wafer-thin slats and then ignore their clients who complain that their butts are sagging to the floor!

Anyone can replace their bed slats with 0.75” or thicker plywood to greatly increase the strength of the bed frame. Remove the existing slats, measure the bed frame, cut plywood, and sand edges, and install on the rails. Use two plywood and add center support beams and posts for full, queen, and king.

If your bed slats are old and failing or the cheap manufacturer saved costs with weak slats and your butt is sagging at night you are in the right place to fix the problem quickly and cheaply.

If you want to be quick solution just buy a new Zinus bed on sale for 48% off at Amazon here!

Scott Boyd

1. How to Replace Bed Slats for Twin Size Beds

  1. Remove the bedding and the mattress.
  2. Remove existing slats by removing the screws. If they are fastened with nails please follow the link below to read the process to remove them.
  3. Purchase 3/4” plywood from your local hardware store. Good one-side 4′ x 8′ plywood should be fine.

    Make sure to install it with the one good side facing up so that the bad side does not pick and poke the mattress.

    If you don’t have a truck you can tie plywood to the roof of your car like in the video below.
  4. If you are scared to try this method of transporting plywood you can often pay the hardware store a delivery charge of $15 – 45 dollars to deliver your order.

    They often will deliver even 50 miles away 🙂

    Or offer a friend beer and pizza to use his truck for an hour. My little town even has a taxi company with a half-ton truck for deliveries.
  5. Measure the length and width of the bed frame and cut the plywood. The approximate measurements should be about 75” x 39”.

    The below video has great information and shows how to transport, carry, and cut your plywood. It is worth watching and it is well done, unlike most videos.

    This is the circular saw I have used forever.
  6. Measure the center of the plywood and make a big bright X on the bad side of the plywood with a marker or crayon.
  7. Install the plywood and fasten it to the bed frame with screws or nails to increase strength and reduce noises from the wood moving when weight is added to the bed.
  8. Measure the distance between the bottom of the plywood and the floor.
  9. Mark your lumber with a speed square, book, or the factory end of a piece of lumber.
  10. Cut the length of the lumber, such as a 2×4 or 2×6, and install it in the middle of the plywood and resting on the floor. It becomes a support leg that greatly increases the strength of your bed frame platform.

    Try to convince a small friend or family member to reach under the bed and hold on the X while you drive a few 3.5” nails or screws into it.

    This simple block of wood increases the strength of the platform substantially.
  11. Reinstall the bedding and mattress and enjoy the new platform bed frame that you created!
Scott marked plywood for cutting to length

TIP: Get the staff at the hardware store to cut the lumber and plywood to size at the store. It is cheap or free and it may fit in your car so you save the delivery cost.

If you have a Smart car, or another tiny four-wheel wagon you can have the plywood cut into more pieces to fit in your Dinky Car.

The video below isn’t that great, but it does show Home Depot staff cutting plywood and the guy fits it into his SUV.

TIP: How to cut a 2×4 with a circular saw video below. He uses a speed square, but if you need to watch the video to cut a 2×4 you aren’t likely to have a speed square at home. You can use a book to mark 90-degree cut lines on the board, or cut a piece of the 2×4 off and use the factory square edge to mark straight lines.

TIP: If the slats are nailed in place on your bed fame then feel free to read how to remove them in my article Should You Screw Down Bed Slats here and scroll a little more than halfway down.

TIP: When you go to the hardware store and order your material and delivery be sure to go to the Contractor’s Desk to pay. This is a separate section for contractors.

Tell them that you are working on a small project now and will be starting a larger project next week (like a garage). They may be able to waive the delivery charge and/or provide you with a Contractor Cash Discount.

I have also just added a 4′ x 8′ sheet just under the mattress to cure the problem and you can see how here.

Scott Boyd

Cash contractors get a 5% discount at one of the two hardware stores in my area, so it is worth asking (unless you go to the big box hardware stores like Home Depot and Lowes),

It may only be five percent, but a penny saved is a penny earned… I hate that saying. If we earn $1,000 per week in the USA or Canada more than $500 of that paycheck goes to taxes.

So really a penny saved is two pennies earned.

I got curious to see if there is a way to save money while shopping at the big box stores and Kai Andrew uses a pretty novel way to get 12 – 20% discounts at these stores.

It is not something that I thought of and it might help some of you save some money.

I wrote about the best wood options here so you can compare each to help you decide.

Scott Boyd

2. Replacing The Slats in Full and Queen Size Bed

  1. Follow the instructions for the twin bed up to and including step 4 except that you need two sheets of plywood and a 2x4x10′ piece of lumber.
  2. Measure the width of the bed frame, which should be approximately 54” wide.
  3. Cut the length of the two sheets of plywood.
  4. Place one on the bed frame tight to the head end of the bed.
  5. Measure the remaining gap and cut the second plywood to fit the remaining gap.
  6. Cut the 2x4x10′ to length for the bed frame. This will provide a beam under the plywood in the center from the head to the foot of the bed.
  7. Measure the distance from the bottom of the plywood to the floor and subtract 1.5 inches.
  8. Cut two pieces of 2×4 from the lumber scrap.
  9. Fasten these two pieces to the 2×4 beam 12 inches in from the head end and 24 inches from the foot end.

    And this is the cordless drill I use and it is 70% off at Amazon… maybe I need a new one too!
  10. Slide the beam and posts under the bed and position it so that it is in the center.
  1. Fasten with nails or screws through the plywood every 12 inches. Be sure to countersink (like this) the tapered screw heads to prevent damage to the mattress.

TIP: To save money there are many ways to find free lumber. Rather than me writing about it, I looked to see if anyone did a video on the topic and YES, Wood By Write did a great video with lots of places to find free wood.

Scott attaching 2×6″ lumber.

3. How to Replace King and California King Size Bed Slats with Plywood

The modification is the same as the full and queen modifications except that the length of the bed frame is longer and the width wider.

According to Pacific Wood Products, their plywood at worst provides a capacity of 54 PSF (pounds per square foot) with a clear span of 36 inches from the center post and the bed rails.

This is adequate, but if you aggressively attach or jump on the bed you should consider installing two beams and posts to handle the abuse.

The Pacific Wood Products plywood load span tables can be reviewed here.

TIP: Some hardware stores sell plywood larger than 0.75 and if available it provides more strength for queen, king, and California king bed frames.

It does cost more and it is HEAVY, but if you and your significant other buy your clothes off the plus-size racks the extra cost and weight of the stronger plywood is a good idea.

Scott cutting 7/8″ with a circular saw

4. Easiest Way to Replace Slats with Plywood

Install plywood over the existing wood or metal slats. Why bother to remove the existing slats that are providing strength? The mattress will only raise 0.75 inches with the plywood added on top of the existing slats.

TIP: Use plywood, not OSB or MDF. OSB will pick at the mattress material and MDF sucks. It is sawdust and glue and it will warp and bend over time as there are no wood fibers to give it much horizontal strength, especially with two people laying on it.

TIP: If your existing slats are still providing some support you may be ok to use 0.5-inch plywood on a twin bed and 0.63 (5/8) on full beds. This can save a few dollars.

TIP: Cut the corners off of the plywood, and round them slightly if you can. Then lightly sand the plywood edges with 40 – 60 grit sandpaper to reduce the chance of damaging the mattress or scrapping your legs.

For more tips and tricks to using plywood and which types and thicknesses to use please check out my article here.

For more information please see:

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