Best Subfloor Screws and How to Install Subfloors

Buckling and squeaking are the major problems you might experience when you live in a home with a subfloor. These issues start to manifest themselves or become evident over time due to underlying factors. The buckling and squeaking sound are brought by poor arrangement and spacing of the subfloor sections, the type, and the size of the fastener used to secure the subfloor to the joists. Fortunately, these problems are temporary, meaning they can be eliminated by repairing the subfloor or replacing it with a new one. The primary purpose is to help you employ the right tools and guide on how to install your home interior subfloor.

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What is the best way to fasten a subfloor?

 

 

There are two common methods used for fastening the subfloor to the joist panel. They include; screwing and nailing techniques. The nailing method is effective, but it has its disadvantages compared to using screws to fasten a subfloor. The primary reason why nails are limiting is that they do not have high tension resistance. Therefore, it is easy for them to become loose, making the subfloor start squeaking and buckling with time, thereby inducing a lot of expenses repairing the floor with time.

Contrarily, using screws is much better than nails because it has a spiral spiraling design, making it have a high tension resistance. Thus, they hold the joists and the subfloor much tighter and in place for a long time, thereby eliminating repair expenses. Secondly, they are made from long-lasting material like steel making them long-lasting than their counterpart.

 

Are screws better than nails for subfloor?

Yes. Screws are better than nails for securing the subfloor against the joists. If you have been having a hard time choosing nail or screwing for fastening the subfloor, below are the reasons why screws are better nails;

• They last longer depending on the type of screw. There are three types of screws. They include; Steel screws galvanized screws and drywall screws. All are made of steel, but galvanized is long-lasting and resistant to chemical reaction.
• They have a threaded structure that helps secure the subfloor tightly to the joists without causing minimal fiber damage. Thus, they make the floor much quieter and do not loosen or come off quickly, unlike nails.
• They can sustain a lot of pressure and lateral force without snapping and warping. However, do not use drywall screws on the interior subfloor because they cannot sustain the regular stress of wear and tear.
• They are the best option for securing engineered wood subfloors than nails.
• They are cost-effective in the long run because of their durability, chemical resistance, and high tension resistance, thereby eliminating regular repair expenses than floors secured by nails.

The disadvantage of using screws is that they are expensive and time-consuming because they are tough and need experience when securing them. Despite being not preferred in the place where screws are better, nails also are significant when:

• You are working under a tight or fixed budget because they are pocket-friendly than screws. Hence, it is more appealing to industrial use and DIY home renovations.
• They are straightforward, which makes the securing process very easy and less time-consuming.
• They are also flexible, meaning you can re-shape them to their original shape; unlike screws, they cannot be reused or molded back to their original shape when they are damaged.

However, for improved gripping, if you are under a tight budget and do not want to use a nail, we recommend using ring shank nails. Ring shank nails are a bit threaded in design, allowing them to have a tighter grip than standard nails. All in all, if you want a subfloor that is free from buckling and squeaking, you should secure the subfloor with screws because they provide excellent gripping and tension and are durable than the standard nails.

 

How do you screw down a subfloor?

Now you are fully aware screws are better than nails, but they are still significant when securing down a subfloor with screws. To successfully screw down a subfloor using screws, follow the procedure below;

• Arrange the subfloor sections properly by lining them up together to create better support and balance. Nevertheless, ensure you inspect the panels, especially at the grooves and tongues, because they are highly susceptible to damage. Arrange the subfloor sections perfectly straight and square with respect to its joist joints.
• Apply a subfloor glue/adhesive across the joists in a zigzag pattern to hold the panels together and to avoid skinning over the other. Then, where the panel ends, apply double beads while leaving 1/8” space between panel ends to prevent the subfloor from buckling. Before using the adhesive, be sure that all joists are dry and free of grimes and residues.
• Set the floor {plywood or treated timber} on the joists with the groove exposed with a 1/8-inch gap from each end of the edge. Use a framing or sledgehammer and a beater box or tapping block to prevent the tongues from driving towards or into the grooves. The significance of leaving the track exposed is to permit the floor to flex and expand when fastening and to prevent the subfloor from buckling.
• Re-confirm if the subfloor fits against both sides and tap each corner with nails/screws to allow quick and straightforward fastening of the subfloor. However, while tapping the floor, you should leave the screws 3/4-inch out of the floor. This allows you to easily pull them out when you want to make adjustments before you permanently secure the subfloor to the joists.
• If everything is okay, fasten the subfloor to the joists using screws with the necessary tools for securing the screw. While screwing, the spacing distance in the field between each screw should be 10-12 inches on the surface and 6-inches on the edges parallel to joists. If you are fastening a plywood floor, you should leave 10-inches towards the tongue until the next subfloor sheet is installed.
• After you are done with screwing the subfloor to the joists, use a circular saw to trim the edges of the subfloor sheet to have an excellent finishing.
• Seal the screw head and any openings with sealer if necessary and apply weather-resistant paint on the subfloor to prevent the floor from getting damaged by water.
• You can add another layer over the Subfloor to keep the room warm and comfortable. You can use carpet or engineered floors that are friendly to the feet and keep the floor warm.

The thing to consider while fastening the subfloor to the joists with the screw before you start screwing, there are factors you should consider:

• The distance between the joists and the subfloor thickness

The interval distance between two joists determines the thickness of the subfloor, and the further the length, the thicker the subfloor. The thickness increases with increased distance between the joists for stability purposes. For instance, if the space is 12 to 20 inches, the subfloor would probably be ¾-inches thick. Therefore, you will fasten the subfloor with a screw that will penetrate below the surface of the joists by at least 1 inch from the surface subfloor surface. Thus, the rule of thumb suggests, if the subfloor is ¾-inch thick, you will need a screw that is 1 3/4-inch long and maximally should not exceed 2 inches long.

If the joist’s distance exceeds 20 inches, the subfloor thickness would be 1.5 inches, possibly requiring a subfloor screw that is 3-inches long. The subfloor screw should be 1-inch longer than the subfloor thickness to make the bond between the joist and the subfloor firmer and tighter. Therefore, you should avoid using smaller subfloor screws about the subfloor thickness to avoid making loose-fitting subfloors that will soon start buckling and creaking. Furthermore, avoid using longer subfloor screws because they may end up splitting the underlayment of the subfloor.

• The head type of the screw

The head of the screw also determines if you want their head to sink flush with the surface or not. Below are different types of screw heads that you may find suitable for your Subfloor. They include;

Truss head

This type of head is also known as Mushroom head screws. Mushroom head screws are designed with a broader head that is rounded in shape and is excellent for mounting hardware purposes.

Trim Head

This type of screw has been designed with the head trimmed, and before screwing them on the surface, you will first need to drill a hole on the surface. The advantage of this type of head is that it provided a sink flush finishing and is recommended for screwing delicate woods parts from splitting. However, they offer less holding power making them not suitable for the subfloor.

Bugle head

Bugle heads are mostly ¼-inch in diameter with countersank head design followed by a concave surface. Bugle head screws do not require pre-drilling a hole for you to install in the subfloor, thereby making it time-efficient. The other advantage with bugle head screws is that they sink-flush with the working space and allow a more broad bearing stress distribution.

Washer head

Washer head screws have a round head design with built-in washers. The built-in washers allow the screw to self-drive itself easily inside the surface; therefore, there is no need for pre-drilling the workspace. Secondly, they evenly distribute the weight better, making the bond stronger and tighter. This type of screw is mainly used for intensive woodwork projects.

• The Diameter of the Screw

Screws also have been designed in different diameters which indicates the thickness size of the screw. The thickness of the screw can either make the bond between the subfloor and joist be stronger and tighter or destroy the joists and subfloor surface. The diameter thickness of the screw should be a first-hand priority when you want to fix the screws at the edges of the subfloor. This is to prevent damaging the subfloor surface and the subfloor underlayment. The common screws diameter that is used for fastening subfloor is size 8, 10, and 12.

• What screws to use on the subfloor?

The last factor to consider is the types of screws to use on the subfloor. There are different types of materials used for making screws which are also designed for different purposes. Therefore, you should be able to choose screws depending on their quality and the type of subfloor material. They include as follows;

Steel Screws

Steel screws’ have a spiral pathway that is a helical thread in the design. Steel screw is suitable for plywood because it does not or minimally harm the fibers of the OSB/plywood subfloors. Secondly, they are made from steel metal making them have a shear strength that can sustain a lot of lateral movement without warping and also hold the subfloor intact with the joists.

Galvanized screws

Galvanized screws are also steel screws, but with an added special coating to protect them from rust caused by weathering elements such as moisture. Therefore, if you intend to screw treated, untreated subfloor, and exterior floors such as deck and porch floors, we recommend you use galvanized screws. Moreover, galvanized crews are much durable than steel screws because they can withstand chemical reactions.

Drywall Screws

Drywall screws are purposely designed for installing wood and steel frames on the wall. Drywall screws’ shear strength is not stronger enough to withstand the rigorous activity of the subfloor and if you use it for the subfloor its head will start to snap off. Thus, they are mostly used for securing drywall panels.

Should I screw the subfloor?

Yes. You should screw the floor because they provide a tighter and stronger bond between the subfloor and joists. Moreover, they are also easy to unscrew when a repair is needed and can be re-used because they have long-lasting durability.

Conclusion

Using a screw for securing the subfloor to the joist is the best option because it provides more advantage over the nail. It is essential to follow the guide above to help you choose the best screw for the subflooring purpose. However, you should apply a 1-inch thumb rule for selecting the right size for the subfloor screw, the sink-flush ability to create an excellent screw surface finishing, and avoid screws that would require pre-drilling the workspace.

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tags#

  • subfloor screws
  • flooring screws
  • underlayment screws
  • screws for underlayment plywood …

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