This Is How Thick Plywood Must Be Under Your Mattress

sheet of plywood

Too thin and there is no support. Too thick and your pressure points might complain all night long! Here’s how to find the perfect thickness.

The correct thickness of plywood under a mattress depends on how many sleepers use the bed and their weight. Plywood must not be below 19 mm and can be as thick as 40 mm.

Choosing the correct thickness is essential to ensure that the plywood frame does not break nor give you uncomfortable nights. Our guide helps you to choose the best thickness and type of plywood for your bed.

The Correct Thickness Of Plywood Under A Mattress

Plywood is a common material used to craft bed frames. It is particularly popular with those who like to make their own home furniture and projects. But how thick must the plywood be under your mattress and why does it even matter?

Well, the thickness of the plywood is directly tied to how comfortable your mattress will feel and also how strong the frame will be. For these reasons, your plywood needs to measure between 19 mm and 40 mm. The exact thickness will be determined by the size of your bed and how many people are using the mattress. 

Not quite sure about all those terms for a bed? We wrote an article to explain the difference between a mattress and a bed.

How Thick Should My Plywood Be?

If your bed is a single-sized affair and only you (and maybe the cat) use the mattress, then the barest thickness should be 19 mm. Do not go below this measurement, even if you are a very small and light individual. The idea is to use plywood that will last for years and when the sheet is too thin, it will crack and fracture within a few months. 

If your bed is double-sized, the best recommendation is to use a sheet of plywood that is either 30 mm or 40 mm. It does not matter if you are the only person who snoozes in the double bed. The mattress itself also adds weight to the plywood and the thicker the wood, the more durable the sheet will be for the foreseeable future. 

quality plywood sheets

While thicker is more durable, also consider the type of mattress that you are using. Most people love a medium-firm mattress and a thick sheet might add more firmness than you would like. On the other hand, in certain cases, a thin sheet of wood will also make a soft bed feel saggier. Each person experiences the comfort of their bed in a different way. This makes it extremely hard to say which thickness is perfect for each individual. 

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What Type Of Plywood Should I Use?

That is right, DIY masters. Not all plywood is created equal. Unfortunately, there is really bad wood out there that retailers will sell to the unwary and uninformed. You need to understand what you are looking for before you walk into that store and stick to it. There are great plywood types that will not only last for a long time but they will also make your bed frame look stunning and modern. 

One of the most popular plywood types that people use for bed frames is birch. This type of plywood lasts for years and can also be purchased as veneered wood – which looks totally amazing. You will get that glistening and darker look that gives any wooden project a highly professional touch. 

What Type Of Plywood Should I Avoid?

particle board
Particle Board

When you go out shopping for large pieces of plywood, you might run into names like MDF and Particle Board. These should be avoided at all costs. While MDF and Particle Board plywood play valuable roles in other projects, neither is suitable to create a long-lasting and supportive bed frame. Particle Board, in particular, is not very strong and cannot carry the weight of a double mattress and two people (plus the dog).

Did that dog shed a ton of hair or roll in the mud? Grab our free guide on how to clean a bed. It is packed with tips to freshen everything from the bedding to the mattress.

What Should Quality Plywood Look Like When I Buy It?

Once you know the thickness and the type of plywood for your project, the next essential step is to purchase a quality sheet of wood. To assess the quality of plywood, sometimes you only need to use your eyes and fingertips. Let’s look at the common signs of good and bad plywood.

  • Good plywood is straight and has a fresh woody smell or no smell.
  • Bad plywood is buckled and completely avoid if it smells rotten, mouldy or otherwise bad! This smell will get stuck in your mattress and getting rid of a bad odour in a bed is an unnecessary chore.
  • Good plywood will be sold with smooth edges and a smooth surface.
  • Bad plywood will be sold with splinters, dents, a rough surface and unworked corners.
  • Good plywood will be kept clean by the retailer so that it presents well and reaches the customer in a good state.
  • Bad plywood is often clean but if you do spot a dirty sheet, rather walk on by. 
  • A reputable store will not push the sale. 

Watch Out For That Mattress Warranty

One thing that can stop your project in its tracks is the warranty of your mattress. Some bed manufacturers will cancel their guarantee on the spot if you use any frame other than the one that they recommend. These brands are not being mean – some mattress designs really do not work well with plywood and this could cause your expensive bed to fail years before its time. One can understand why a company might not want to cover such an event. If your mattress is under a warranty, read the rules carefully to avoid damage to the bed and the cancellation of the guarantee.

A Quick Summary On How Thick Must Plywood Be Under A Mattress

  • Plywood is a popular choice for DIY masters who need a new frame for their mattress.
  • Plywood should never be thinner than 19 mm and this thickness is better suited for a single bed and mattress. 
  • The most used thickness is either 30 mm or 40 mm.
  • It might take a test with the plywood and a mattress to feel if they are comfortable together.
  • The best plywood to use is birch.
  • Avoid plywood that is labelled as MDF and Particle Board. They are not strong enough.
  • Learn the signs of quality plywood before you buy a sheet for your project. 
  • Always check the warranty rules of your mattress to ensure that a DIY plywood frame does not cancel the guarantee.