Subfloor Screws: How to Choose the Right Ones

Whether you are remodeling, replacing, or re-securing the floors of your home or your property, something that you will quickly encounter is the subflooring. When you get to the subflooring, you will then soon be encountering everything that comes along with the subfloors. One of those things is picking the right tools to use for the flooring. People have a lot of questions when it comes to installing subflooring, but there is one huge one that is most common and one of the most important things to ask. And that is, what is the right type of screws to use for installing subflooring?

There are two types of screws you can use when installing subflooring, steel screws and galvanized screws. Steel screws are most often used for interior subflooring. On the other hand, galvanized screws are most used for exterior flooring.

subfloor screws

Although picking the type of screw is one of the most important parts, there are a few other things that you will have to pick as well. The biggest thing is picking out the sizes of the screws, meaning the width and length of them. It will ultimately depend on the materials you are working with though. To find out more information about picking the right screw to use when installing subflooring, keep reading this article!

Types of Screws

As mentioned above, there are two types of screws that can be used when installing subflooring. These are steel screws or galvanized screws. Choosing the right screw will really depend on the project and its location, whether it is for outside or inside floors. Some people do use other types of screws or even nails, however, they don’t work nearly as well for subflooring.

Steel and galvanized screws are specifically made with subflooring in mind which is why they are the best types of screws to use. You want to be sure to use screws that are strong enough to keep the wood from moving, and long enough to keep everything secured for a long time.

Steel Screws

Steel screws are the go-to screws when installing subflooring. These screws are most often used when installing interior subflooring. Steel screws are also the most common, and most recommended, screws used for subfloor installation. Part of the reason for this is because they keep the plywood from breaking and cracking while they are being installed. They are also very strong and durable, they won’t warp, break, or move around for a very long time.

Screws also help to prevent squeaky floors, which get annoying very quickly. This means that you won’t have to worry about the subflooring for quite a while since everything will be secure and not make any noise.

Galvanized Screws

The other great option for installing subflooring is galvanized screws. Galvanized screws are most often used for exterior floors, for example, porch floors and deck floors. The reason that these screws are such a great choice for installing exterior subflooring is because of a special coating that they have on them.

This special coating, that the manufacturers put on them, helps prevent them from rusting quickly and from deteriorating as quickly as other screws. This means that they can withstand all weather conditions for a lot longer than any other type of screw. You won’t have to worry about the subflooring for some time. Galvanized screws also help prevent your floors from squeaking, which is mentioned with steel screws as well.

Screw Size

Another important thing that you will have to think about is the size of the screws. You’ve figured out the type of screw that you need, whether it is a steel screw or a galvanized screw, and now you have to pick the right length and width. This is not as important as pick the right type of screw to use, but it is still very important to be sure that your floors will stay very secure for as long as possible.

When using a ¾ inch piece of plywood, you will want to use a number 8, 10, or 12 size screw. These numbers represent the thickness, or width, of the screw. If you want to get even more technical about it, the numbers represent the diameters of the screws.

Picking the right length of the screw is a bit more complicated than just picking the right number though. Most commonly, a 3-inch screw is used. This is especially true when using a ¾ inch piece of plywood. But if you use a thicker piece of plywood, or a thinner one, the length of screw that you will want to use will be different.

You want to make sure that the screw you choose to use is at least an inch longer than the plywood. This will make sure that the wood is secured to the joist or to the underneath layer securely.

Why Not Use Nails?

Using nails to install subflooring would be so much faster and easier than using screws. So why shouldn’t you just use nails instead of dealing with the hassle of screws? The main reason you don’t want to use nails is that they will make your floors squeaky.

Nails may seem sturdy, but they can move and wiggle around, which is what will cause the floors to squeak all the time. This can happen right installation, but it can also develop over time. This is why it is best to use screws even if they do make the entire installation project take that much more time.

Screws don’t move around and are much more secure in the joists underneath the plywood. If the floors are already squeaky and you are looking to fix them, replace the nails, or old screws, with new screws. Although nails would be faster, screws are the better choice long term. Screws will take a lot more time and require more hands-on work, but they last longer, are much stronger than nails, and won’t cause nearly as many squeaky floors.

What About Drywall Screws?

Drywall screws are a type of screw that you really want to stay away from when installing subflooring. I know I keep saying to use screws for installing subfloors but make sure to not use these screws in particular. As the name suggests, drywall screws are supposed to be used when installing drywall.

Drywall is not nearly as thick or tough as plywood, so the screws are not made to be as long or as strong. They are made to be used with drywall, not with plywood. And they work very well with the drywall.

But they are just not anywhere near as strong as steel and galvanized screws. Meaning they are not strong enough to be used for subflooring. They can move around and warp easily when under too much pressure. This is why they are great for walls.

But floors tend to have quite a bit of pressure on them, with furniture and people walking on them. This makes drywall screws a really bad type of screw to use when installing your subflooring. These screws will need to be replaced quickly if they even hold up for any amount of time.

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