SOLVED: Adding An Extra Layer Of Plywood Over Subfloor: A Homeowner’s Guide

As the foundation of the flooring, the subfloor is responsible for supporting everything in the house from people to furniture. In general, homeowners should be able to set up the finished floor on top of the subfloor with relative ease. That being said, the surface of the subfloor is always ideal for finished floor and the addition of a layer of plywood is sometimes necessary. While adding an extra layer of plywood over subfloor is not a complex project, it nonetheless requires certain skills and tools for the best result.

Breakdowns Of The Installation Of Plywood Over Subfloor

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So you intend to add an extra layer of plywood over subfloor of your residence soon but have no idea what needs to be done? Then you may want to give this article a look. Down below is everything you must know regarding the installation of plywood over subfloor.


Gather the tools and gears: To get the dimensions of the layer right, you have to grab a tape measure. Additionally, you need to cut through sheets of plywood which is why it’s suggested that you prepare a saw. Pneumatic stapler and galvanized staples would also come in handy as you secure the lawyer of plywood to the subfloor. Last but not least, you should always wear personal protective equipment (goggles, gloves, etc) to minimize the odds of injuries.


Note: Before the installation of the plywood layer, it’s a good idea to put all of the plywood sheets inside the room for acclimation. By doing so, you would be able to eliminate the hassle of addressing the expansion of the plywood following installation. The time it takes to acclimatize plywood changes from case to case but seventy two hours is usually sufficient.

Step 1: Clean The Subfloor

Run a vacuum cleaner over the subfloor a few times to get rid of the dust on its surface. In the case that you don’t have a vacuum cleaner, the broom and dustpan combo is adequate. However, dust could kick up so it’s a good idea to wipe the subfloor with a mop.

Step 2: Collect The Measurements 

Proceed to use the tape measure to determine the dimensions of the subfloor. Assuming that you don’t mess up, it’s a breeze to deduce the ideal size of the plywood layer based on the collected numbers.

Step 3: Cut The Plywood 

After you have established the size of the plywood layer you require, you could get to the cutting phase. Thanks to the uniformity of plywood sheets nowadays, you should have an easy time creating a suitable layer for your subfloor.

Step 4: Set Up The Plywood 

Arrange the sheets of plywood in a way that they sit perpendicular to the sheets of the subfloor. Remember that the plywood seams need to meet on top of the subfloor joints for optimal support.

Step 5: Secure The Plywood 

After the position of individual plywood sheets seems good, hold them in place using the pneumatic stapler and galvanized staples. About the space between the staples, keep staples around the edges two inches apart and nail one staple for every four inches in the interior. Fill the gaps between the sheets with seam fillers, wait for a day and your plywood layer should be complete.

Calling The Pros: Advantages And Disadvantages 

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Overall, once it comes to adding an extra layer of plywood over subfloor is a task, you always have the option of calling the pros. Nonetheless, letting professionals handle the installation of plywood player feature pluses and minuses

  • Advantages: If you manage to hire a qualified contractor, you could get your plywood layer installed in a blink of an eye. Throughout the installation, your contractor would take care of everything from material to labor so you only need to sit tight.
  • Disadvantages: The cost of professional installation fluctuates between locations but you have to pay anywhere from hundreds to thousands of dollars. If you own a small house then you don’t need to worry too much about the expense. On the other hand, if your house is kind of big, you must spend big bucks which may impact your spending plan as a whole.


Which one is the winner in treated vs. untreated plywood?

Regarding resistance against moisture, insect and so on, treated plywood is the winner by all accounts which results in a fantastic lifespan. That being said, for homeowners with limited shopping budgets, untreated wood is the one that comes out on top owing to its affordability. To decide which type of plywood to use, you should give your situation some thought. Feel free to go for treated plywood if you have money to spend but if your wallet is a bit tight, stick to untreated one.

Is it wise to install a thick plywood layer?

The thickness of plywood layers over the subfloor influence the support capacity to a certain extent. Still, it’s worth pointing out that the thicker the plywood layer, the shorter the room. If your room possesses a low ceiling, you should avoid installing plywood layers that prove too thick.

How long do plywood layers last?

A wide range of factors affects the lifespan of plywood layers from elements to human activities. The consensus among articles covering the topic of adding an extra layer of plywood over subfloor is that the plywood would hold together for decades. However, it’s best to keep an eye on the plywood layer of your house. That is going to let you detect signs of issues, resolve them at an early stage and cut down repair costs.

Where could I buy plywood sheets? 

Nowadays, you could stock up on plywood sheets by paying a visit to home improvement stores. Despite sporadic changes in prices, the purchase of plywood sheets would have negligible impacts on your spendings. Many stores even provide cutting service to the customers for ease of convenience so there is no need to bother about transportation. In any case, for good measure, stick to well-known names such as Home Depot, Lowel’s, etc.


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