Should You Drill Pilot Holes for Deck Screws? (Avoid Damage)


You’ve probably noticed how often people drill directly into wood without first making a pilot hole. So is it really necessary to drill pilot holes?

It’s recommended by professionals to drill pilot holes for deck screws. Pilot holes help to avoid putting pressure on the wood that surrounds the screws. Pressure can weaken the wood, causing it to split or crack. Pilot holes also enable you to drive the screws with greater accuracy for a more aesthetically pleasing finish.

In this article, I will show you:

  • Why it pays to drill pilot holes
  • The right way to drill pilot holes
  • How to correctly install deck screws

Is it necessary to drill pilot holes for wood screws?

It’s not absolutely essential that you drill pilot holes, but it is recommended by most professionals that you do. If you don’t pre-drill the wood, there is a much higher chance of the wood splitting when you try to put in the screw.

This is because you’re putting a lot more pressure on the wood around it, which causes it to weaken and crack. So pre-drilling the wood is worth doing as it greatly reduces the risk of splits and cracks in the wood.

If you’re using a solid type of wood, then screws will hold better and for far longer if the wood has been pre-drilled with either a pilot or clearance hole.

Clearance holes are holes that are drilled into the top of the wood to prevent jacking. The clearance hole needs to be large enough that the screw will fit through it without the thread biting into the wood.

How to drill pilot holes for wood screws

When drilling pilot holes for wood screws, it’s important to do it properly. The steps below show you how:

  1. Make sure your drill is in good working order and is safe to use.
  2. Insert the appropriate drill bit for the size of hole you need to make.
  3. Use a pencil or something similar to make a mark where your hole is going to be.
  4. Select level two on your drill.
  5. Making sure that your drill is straight and level (so that you are drilling at 90 degrees).
  6. Drill the pilot hole through the top deck board and into the joist underneath.
  7. Swap your drill bit for a brad point drill bit.
  8. Change your drill speed to level one.
  9. Again, make sure that you have the drill angled so that it is straight and level for where you are drilling. Now insert the screw while ensuring the head is flush with the board.

Other important factors to consider:

  • Your pilot hole should never be any smaller than the minor diameter of the screw.
  • If the wood is hard or if the threads of the screw are quite deep, then make the pilot hole a bit bigger than the minor diameter of the screw, but not too much. If the wood is soft then make it a bit smaller.
  • Always make sure that you enlarge the pilot hole (to make a clearance hole) so that the screw will pull the two pieces of wood together firmly.

A clearance hole should be no smaller than the major diameter of the screw. If you don’t make a clearance hole, then there will be a gap between the pieces of wood.

Glue will be ineffective at filling as the gap would be too big. Glue should only be used to fill in small gaps, those that are no thicker than a sheet of paper.

How to install deck screws

When inserting deck screws, it’s also important that you do them correctly:

  1. First of all, you’re going to need a screw kit that contains stainless steel screws that are no less than 2.5″ long. I recommend this deck screw kitOpens in a new tab. as the screws are corrosion-resistant, meaning they’ll be able to withstand the elements
  2. Place your deck board onto the frame and mark it to show the location of the baseboards underneath.
  3. Select the lowest speed setting on your drill so that you have as much control as possible.
  4. Insert the deck screws around one inch in from the edge of the board. It’s important not to go too near the edge or there’s a chance of the boards splitting. When inserting the screws, make sure you drill them in straight and use your weight on the drill to screw them down firmly.
  5. Make sure that the head of the screws are level with the board or just slightly recessed.
  6. Space the screws out on each board so that they’re an equal distance apart. This will help to ensure that they’re not noticeable, blending in with the boards.

The deck screws I recommended are made from 350-type, 304-grade stainless steel, which makes them perfect for a number of different jobs: from fencing and decking to general wood-working projects. They are corrosion-resistant and can be used for all types of wood – hard, soft, and pressure-treated.

Frequently asked questions

What length screws should I use?

Usually, deck screws are around 8-gauge and have a length of no less than 2.5 inches so that they have a sufficient size to screw the decking boards down onto the framework.

However, a lot of professionals use screws that are around 3 inches long for extra security and to protect against the pressure of boards that shrink or warp.

Nails or screws?

You never use nails for decking as they can easily pop out of the wood and can be dangerous. Although they are often cheaper than screws, they rust easily. Screws do not rust also give a much firmer and more secure finish to the decking.

How deep should deck screws be?

Deck screws should generally always go at least halfway through the decking boards to give a firm hold. It’s important to remember that they should always be around one inch in from the edge of the decking board and never less or your wood could split.

Do you need to countersink deck screws?

Usually, when you insert a screw, you don’t screw it in any further once the head reaches the board. However, countersinking is when you insert the screw a little deeper so that its head goes down into the wood some, instead of only being flush with the top. It is generally okay to countersink deck screws.

How many deck screws to use on a 6-inch board?

For 100 sqft of decking using 6″ boards and 16″ joists, you would probably need around 350 screws.

It is advisable to use two screws every time a decking board and a joist cross and also to use three screws when fastening the boards to the rim joists.

What are the best deck screws?

Deck screws really need to be able to cope with all different kinds of weather, including a lot of rain. Screws that are resistant to corrosion are essential. The best ones to buy are galvanized or stainless steel deck screws.

Graham Walsh

I want to share everything I know about power tools in order to help you. Whether you're a home enthusiast or an industry professional, I have the information that you need.

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