#8 or #10 Screws for Decking - WoodCritique (2024)

In the past, you’d only have to choose between Phillips or slotted screws. You would be ready to start your work as long as you picked a suitable length. However, days are changing, and the fastener market keep making significant strides. For most woodworkers it’s a neck to neck discussion on #8 or #10 screws for decking.

It would be best for the screw to enter at least ½ the bottom material’s thickness. Also, screws are available in gauges ranging from two through 16. Hence, you can easily get an ideal accessory for your work. In addition, you do not have to go for the #8 average size all the time. Check out the #12 to 14 size when working with heavy or thick material. Or #6 for finer woodworking applications.

That said, let’s engage in a more detailed discussion on decking screws.

What Length Decking Screws Should I Use UK?

You probably know that deck screws are the best for fixing deck boards. But do you know the recommended length? Well, here it comes. The screw length should always be at least 2.5 times the board’s thickness. Also, it would be best to position the screws at quarter points, 25mm in from the board ends and 25% in from its edges.

Most decking screws are #8. But you need a minimum of 2½ inches to hold your decking boards to the joists. Also, it would be best to have three-inch screws to add extra holding power against the upward warping or shrinking pressure.

On top of that, ½-by-6-inch lag screws are suitable for installing railing posts to rim joists. Please also consider six-gauge one-inch screws for lateral joints that hang from the rim joist. This way, you provide a safety feature to support the project’s weight in an emergency.

Should You Pre Drill Deck Screws?

It is not mandatory to pre-drill wood screws. But it is recommended that you do so. Not drilling pilot holes before having the screws can mess you up. The exercise puts extra pressure on the surrounding wood. Therefore, it weakens the lumber increases the risk of cracking or splitting.

Pre-drilling deck screws is usually more of a precautionary measure. We hear it all the time: Prevention is much better than cure. Therefore, you may not see the benefit now. But the strategy will always pay off eventually.

In addition, the most effective and durable fastening power comes from pre-drilled holes. Hence, please have some clearance and pilot holes on solid wood before the actual installation job.

Clearance holes are exceptionally useful. You drill them through the board’s top to prevent jacking. Also, they should be big enough for the screw’s body to fit effortlessly. Or else might end up having threads immersing in the lumber.

Lastly, pre-drilled holes prevent timber splitting, especially at the board’s ends. In addition, they help you have the recommended 2mm oversize pilot holes on hardwood timber. Thus, you allow seasonal movements to occur without damaging the lumber.

Do You Need to Countersink Deck Screws?

Generally, you stop driving the screw into the wood when its head hits the surface. But, interestingly, countersinking encourages you to continue driving the screw below the surface. However, it would be best to check if your project or application techniques accommodate countersinking. For instance, it is okay to countersink screws if you face-drive them.

So, just to give a simple answer: It would be best to countersink deck screws. More so, you’ll get a clean finish once you set them about ⅛ inch below the deck’s surface. Running your hand over the deck only to catch screw heads and slivers can be so annoying. Thus, please countersink the screws as they will remain below the surface even after the deck shrinks.

What Size Drill Bit Should I Use For a #8 Screw?

A ⅛ inch drill bit provides the best pilot hole for the #8 screw. It is also suitable for hardwoods such as maple, oak, and walnut. However, the size may vary depending on the material you are using. For instance, you may need a narrower pilot hole for soft materials.

The drill bit size refers to the bit diameter you use for creating pilot holes. But it does not need to match the screw diameter. You need the threads to penetrate the material effortlessly. On top of that, it is always wise to determine the best drill bit for a #8 screw. So, you create accurate pilot holes that allow for secure fastening.

Also, an ideal strategy to use is to have the bit diameter match the screw’s shaft. Also, you do not have to account for the protruding threads. This way, you can allow the threads to go through the material and function as a fastener.

Even so, this technique may not apply in every scenario. Always examine how much weight the screw will hold and how various materials behave. Also, you could consider different bit types.

For instance, it would help to have U-shaped pilot holes with straight walls if you want a straight drill bit. On the other hand, you’ll need V-shaped pilot holes for a tampered bit.

Besides that, the tampered holes allow more contact between the screw and the material. Thus, it can be quite difficult to install the fastener. But still, you’ll have a more reliable structure that can withstand more weight.

What Size is #8 Deck Screw?

By now, you know that we have 16 standard sizes in the deck screw sizing system. The numbers range from 000 to 14. And more specifically, a #8 deck screw has a 0.164 diameter. Also, though the screw can feature 32, 36, or 40 threads per inch, the nearest fraction is usually 5/32.

#8 screws are common accessories with a variety of applications. In addition, you’ll come across them while working on multiple projects. Hence, it would be best to know the right size drill bit and other relevant specifications.

Besides that, these screws come in handy for multiple wood construction jobs. You can use them to attach wood boards to wall studs, connect wood to wood, attach fiberboards to door frames, or secure thicker boards.

Also, you’ll often find the #8 screws with threads and pan heads that cover the entire screw length. But, these kinds work best for sheet metal fasteners. So, please assess your project and get the ideal accessory.

What Is the Shear Strength of Deck Screws?

Shear strength is the maximum load that a deck screw can support before fracturing. This strength depends on factors such as the screw length, thread type, screw quality, insertion technique, and the force you use.

Besides that, please note that deck screws do not have the same strength as jolted joints and bolts. But, they can hold between 75 to 125 pounds. Also, more quality screws can handle above 200 pounds per screw.

In addition, the thread type determines if your screw can hold more weight. For example, coarse threads feature an increased space between each thread. Hence, they can hold strong even on soft surfaces.

What’s Special About Decking Screws?

Screws are essential construction accessories that come in various sizes and shapes. Woodworkers, even all screws are the same as the tools join parts. Did you know that we have wood and deck screws? And they are different despite having a similar appearance?

Well, decking screws are stronger than wood screws. They are often copper or stainless steel products, which makes them special. Also, they have corrosion-resistant attributes that make them perfect for outdoor wood.

On the other hand, wood screws are mainly from steel material and feature a flat head. They have an unthreaded shank and thus make strong joints. However, they do not cope well with element exposure.

Therefore, you are safer using deck screws for exterior jobs and wood screws for light, interior work.

Where Do You Put Screws In Decking?

Where you position deck screws is essential, or the structure will not be compact for a long duration. For example, it would be best to place the screws about one inch to the inside of the board’s edge. This way, they are not too close to the edge, and you risk fracturing or splintering the boards.

Set the drill at the lowest level to give you sufficient control over how deep you want the screw to go. The idea setting involves putting your weight behind the drill and driving the deck screw down into the wood. Also, please keep checking the screw to avoid installing it at an angle.

In addition, ensure that the screws are flush with the board’s top. They can be slightly deeper than the flush too. That positioning is alright as long as the screws are not too low or too high on the boards.

Finally, install the deck screws approximately the same distance apart for every board. Otherwise, you will notice an obvious skewed screws pattern on the deck floor. Also, remember that your goal is to have unnoticeable accessories that form an understated part of the deck’s appeal.

What Is the Best Way to Screw Down Decking?

The surest way to secure deck boars is by using the top-down screw method. It involves using two screws on each end and having two screws towards the board’s outside at every joist. This way, you hold the boards tightly in place, and they will not cup or warp.

Also, you can easily fix the boards if they cup upwards. Unscrew and flip them. Then, re-screw them down.

Why Are My Decking Screws Snapping?

Deck screws snap due to a combination of factors. For example, the boards may shift over time. This event alters the pressure on the screws, and they end up snapping. Also, you will experience snapping deck screws if you get poor-quality accessories.

You may wonder why the deck boards shift in the first place. Well, they are usually natural wood materials. Hence, they can dry out or absorb excess moisture. So, you experience contractions and expansions.

Fortunately, you can avoid this annoying scenario by investing in good-quality screws. They can hold tight and survive minor warping instances. Also, you can have more screws on the board to reduce cupping.

Besides that, the absence of pilot holes leads to deck screws snapping. Driving a screw on a solid wood surface causes strain on it. Therefore, you risk breaking it together with the deck boards.

What Are the Best Deck Screws for Treated Lumber?

It would be best to get special screws for pressure-treated wood. Otherwise, they may slip or bend and corrode because of the preservative chemicals in the lumber. Fortunately, I have a list of what to look for as you make your purchase.

• Camouflage Level. The screws should offer a high camouflage level. Hence, please ensure that they match the plank by getting compatible colors. Also, it would be best to confirm that the screws smoothly blend with the deck after installation.
• Drive Type. It is essential to get screws with the correct drive type. This element plays a primary role from installation to maintenance. For example, a suitable drive type reduces debris, chips, and dust, offers quick installation, and prevents cam-outs. On the other hand, the attribute helps you change, wash, and repair planks easily.
• The Tip’s Style. The correct tip delivers ease of installation and helps to preserve the deck’s structural integrity. More specifically, it would be best to get screws with advanced engineered tips. Conversely, a wrong tip can crack and split your wood.
• Weather Resistance. This attribute is probably among the most important. You should always ask yourself if the screws can ‘withstand the storm.’ Then, go for accessories that have weather resistance qualities.
• Strength Of Adhesion. Your deck’s structural integrity depends on how you connect the planks. Therefore, the screw’s strength in terms of adhesion matters. Also, it would be best to consider deck screws with reinforced shanks or necks as they have superior adhesion strength.

Now that you know the qualities to scout for when choosing deck screws. Let me highlight some of the products you’ll find in the store. Feel free to assess and vet them based on your project requirements.

• Eagle Silver Stainless Steel Deck Screws. These accessories are perfect for pressure-treated lumber. They have a burnished polish and an anti-corrosive coating that gives them longevity. In addition, they are anti-rust screws and work well even in wet areas.
• SNUG SNG919 Tan Fence & Deck Screws. The product package features 100 pieces of self-drilling screws. Therefore, you do not need to keep dashing to the store for more screws. You will also not need pre-drilled holes to install the screws securely as they are self-drilling. On top of that, they feature a left-handed threading system and camouflage beautifully into the deck.
• Kreg, Deck Screw (box of 700) SDK-C2W-700. Kreg deck screws fit right in if you have Kreg’s deck jigs. But they will still work for other multiple projects as they feature neutral coloring and a trimmed head. Hence, they camouflage perfectly with your work. In addition, they have a KTX square drive feature that reduces driver slippage and spinning.
• Hillman 48419 Deck Screws (Pack of 310). These accessories possess an anti-corrosive layer that has passed the 1,000-hour salt spray test. In addition, they have advanced reinforced shanks and countersinking nibs.
• Lightning Stainless, Silver Deck Screws. The deck screws have a self-tapping tip that delivers an effective and yet effortless installation session. They also possess a right-handed threading system that assures you the ease of use. On top of that, the screws’ threads even out exerted force and thus showcase superior driving and holding strength.

Should You Nail or Screw Deck Boards?

It would be best to use a combination of screws and nails on your project to get a perfect product. Moreover, you’ll observe that some building regulations and project specifications for decks include both accessories. There are areas where you’ll need nails, while others require deck screws.

Additionally, screws are usually superior and useful in laying down the deck. They have a better tensile or fastener strength and hold flush better. Hence, the boards will not pop over time. On the other hand, it would be best to use nails for joists and structural elements. Otherwise, you’ll need to use more expensive structural screws.

Unfortunately, structural screws are not an ideal fastener and may not meet existing building codes. Therefore, your deck build may not pass an inspection. So, it will be a good idea to get some nails right from the start.

Besides that, screws are easier to remove, whereas nails are easier to install without needing a power tool. Also, you do not need to have pre-drilled pilot holes for your nails. Thus, you’ll complete your work faster.

What Size Countersink Bit For #10 Screw?

The best countersink bit size for the #10 screw depends on your project. For example, tampered pilot holes on hardwood, you need a 13/64 inch bit. On the other hand, it would be best to work with a 3/16-inch bit for softwoods.

Also, a straight pilot hole requires a 9/64-inch countersink bit size. However, some softwoods will benefit from a ⅛-inch one.

Should a Drill Bit be the Same Size as a Screw?

Choosing a drill bit appears like a small aspect of the deck-building process. But it can make or break the project if you do not take care. Hence, please think of the drill bit as a foundational block for your entire project.

That said, a drill bit should not necessarily be the same size as the screw. However, it would be best if it is the same size as the screw’s shaft without accounting for the threads. Also, you can check out the measurements on the product package to get it right.

Besides that, it will help to learn how to choose the perfect drill bit for your screws. But the infinite decimals and fractions used can confuse you. Thus, you may wonder if you will ever get the exact accessory for your work.

Luckily, I have some simple tricks to help you out in your examination. Here they are:

• Get the screw in question and the drill bit that looks similar to the closest size. Then, line the accessories up and assess if the drill bit shares the same width with the screws without the threads. If yes, you are good to begin your work. On the other hand, you might end up making bigger holes if the drill bit shares the same size with the screw and the threads.
• Evaluate the labels on the screws and bits packages. Most manufacturers label the actual bit’s dimensions on the kit. Also, you’ll find all you need to know about the screw on the box or bag.
• Finally, do the opposite of the first trick if you are suing washers and other equipment that require a loose screw. Line up the drill bit and screw and ensure they share a similar width, even with the threads. This way, you prevent the screw from holding too hard against the surface. Thus, you can use your washer effortlessly.

Conclusion

These days, the screwdriver is not the only means of installing screws. Instead, we have cordless drills and drivers that have made work much easier. In addition, you’ll experience minimum metal stripping and bit slippage as you work. But, as much as we have perfect screw installation tools, do you know which screws work best for the deck? Let’s engage with the following topic and save you some trouble.

#8 or #10 Screws for Decking

The essential attributes to look out for include the screw’s length and thickness. More so, the general rule is that the screw should enter at least ½ the bottom material’s thickness. Besides that, please get #6 for finer woodworking tasks and about #12 to 14 for heavy materials.

Tyron Otieno

Tyron is an avid woodworker and writer. He founded this website to help other woodworkers, whether hobbyists or professionals by sharing his knowledge and experiencie after a decade of woodworking.