What a defeating feeling. You drive a screw into the deck board just to see the end of the board split open. Now your entire deck boards needs to be pulled off and replaced or shortened because the end of the deck board has split.
You run and get the old trusty drill. If you predrill the deck boards, then they won’t crack. And then you look back at the deck. Do you need to predrill every deck board for every single screw? That will take hours, if not days, to predrill every deck board.
Good news, wood deck boards only need to be predrilled if screwing within a 1 ½” (38mm) of the deck board’s end. Deck screws installed in the field, not close to the board’s end or edge, need not be predrilled.
Predrilling is required near the end of deck boards to make room for the screw. As the screw is acting like a wedge, driving between the wood fibres. That screw pushes against the decking, splitting open the board.
By predrilling at the end of the deck board, material is removed, reducing the pressure by creating room for the screw shank. Stopping the decking from splitting. While still holding the decking in place.
For screws in the field, at least one joist space away from the deck
board’s end. There is enough material to counter the pressure of the screw to keep the decking together without predrilling.
There are a few exceptions. If you are not using softwood like spruce or pine, the typical wood of pressure-treated decking may need to predrill every screw. Ipe is one of those popular hardwood deckings that will need to be predrilled on the ends and the field. But this is largely because of how hard Ipe is. Your screw will burn out trying to drill through the Ipe decking.
Another exception of needing to predrill pressure-treated decking is if the wood is to dry. Just another reason not to leave the decking layout in the sun for weeks on end before finishing your deck.
“Wet wood,” decking directly from the supplier’s yard, freshly un-tarped, will have more elasticity. Allowing the screw to penetrate the wood without tearing apart the fibres and splitting the deck board. I am not talking dripping water but simply closer to the 19% drying that it came from the mill with.
This is yet another reason to buy your decking from a supplier that stores their decking outside under tarps. It may be convenient, but decking sitting in a large warehouse unstrapped. Dries out. Just like that soft loaf of bread left out on the counter. Within a few hours, it’s all dried out and crumbles as you bite it. The same with decking. As the screw bites into the overlying dried wood, it will split.
But this doesn’t mean that you have to predrill deck boards. There are a few tricks to minimize predrilling.
Ways to Install Decking Without Having to Pre-drill.
Overhang Decking to Minimize Predrilling
It is a good idea to overhang decking boards simple for appearance sake. It creates a nice clean finish to the deck and minimizes water damage to the decks’ substructure. So, regardless of deck splitting, it’s a great idea.
But in regard to limiting splitting and predrilling, overhanging is a great idea. By overhanging the deck board, you provide more material around the screw. The extra material is holding the board together, preventing splitting.
When I was a kid, I use to play called Red Rover. You line up in two-line, locking hands together. Then one team would call some over from the other side, who would run, trying to break through the line. You would always look for those kids who were barely holding hands to smash through. But if they locked arms or even held up higher closer to the elbow, they were next to impossible to breakthrough.
The same is with deck boards. If you give the decking enough material after the screw to hold together. Locking arms, so to speak, you can drive the screw without splitting the board.
A 1 ½” (38mm) is a nice overhang without becoming cumbersome or weak for walking on.
Of course, that only works when screwing near the deck’s edge where you can overhang the decking. Where you are trying to land two deck boards on a single joist, you only have ¾” (18mm) to screw in. No, where big enough to preventing splitting.
Add Blocking for Decking Butt Joints to Minimize Predrilling
It is a good practice to add blocking to a joist under a butt joint, providing more material to support the decking.
But it also reducing splitting of the decking and thus predrilling. With 3″ (75mm) to split between the deck boards you can screw back a 1 ½” (38mm) from the end, with enough material to prevent splitting.
Use Longer Decking Boards and Transitions to Reduce Predrilling
To avoid butt joints entirely, incorporate longer decking. Using 16′ (4.8m) treated decking boards, plus picture framing. Creates a good size deck for entertaining without butt joints during construction. They may not fit into your SUV but paying a little extra for delivery saving you hours in drilling may be worth it.
Another option if your deck is wider than the deck boards is designing the deck with transitions. I especially love this detail with composite decks but is still worth it with wood decks. But with a wood deck by installing blocking perpendicular between joist space 3″ (75mm) greater than the decking. To support the deck board running perpendicular to the rest of the decking. You can overhang the decking past the joist and 1 ½” (38mm) to minimize predrilling of the deck boards, while adding a little flair to the deck with a creative design.
Back Spin Screws Instead of Pre-Drilling Deck Boards
I wish I could claim that I had thought of this. It has saved me hours. A simple technique to minimize splitting near the end of decking without predrilling. But I didn’t. I learned it from Jeff from Home RenoVision DIY. Here watch the video of him showing how to avoid predrilling deck boards.
He’s got a lot of little tricks in construction but come back to finish learning tips and tricks for you don’t have to predrill deck boards.
Use the Correct Deck Screw Size to Limit Pre-drilling of Deck Boards
Back spinning and overhanging deck boards will help to limit predrilling along with using the correct screws.
The size, or more importantly, the diameter of the deck screw impacts if you need to predrill or not. For 5/4 and 1 ½” deck boards using #8 deck screws treated for ACQ will limit when you need to predrill. It may not seem like much 5/32″ (4mm) for a #8 screw as opposed to 3/16″ (5mm) for a #10 screw, but that fraction is enough to push the decking apart. Demanding that all deck boards are drilled before screwing them down.
Use 3″, #8 screws treated for ACQ for treated decking will reduce how often you need to predrill.
Using Camo Screws to Avoid Pre-Drilling Decking
Similar to overhanging decking, edge screwing is one of those things I love for how it improves the look and performance of wood decking. The screw tucked in on the side of the decking, away from rain, dirt, and eyeballs. The angled screw providing a better hold on the decking, limiting cupping, and so many other things.
Now specifically with Camo screws. Camo screws are designed with a cutting rake tip that augers material out. Combining the predrilling and the screwing into one step instead of two.
Camo Marksman Pro Fastening Tool and screws can be ordered from Amazon or pick up from your local building supply stores like Home Depot or Lowes.
Using Hillman Power Pro Deck Screws Instead of Pre-drilling Deck Boards
If you love face screwing of deck boards and don’t want to use Camo edge screws, Power Pro deck Screws are a good choice. There are many advantages to Power Pro screws, which is why I prefer them over most other decking screws, but there no split twist shank replaces predrilling in most cases.
There are also screws design with a better point limiting splitting. Hillman Power Pro Premium Exterior Wood Screw are with a Type 17 point reducing splitting by up to 75%. Not perfect but an improvement over other screws.
The screw is designed to cut through the decking while boring, making room for the shaft. It does make a difference. Decking requires less predrilling with Power Pro than standard deck screws.
In Conclusion of Pre-drilling Deck Boards
Wood and decking are fragile near the end of the board and require predrilling unless you take some preventive steps. These include design concepts like overhanging decking, blocking butt joints or replacing with transitions to increase the amount of material around the screw.
Instead of predrilling deck boards, you can also change how you screw down the decking. Either by back spinning the screw before driving. Or by using screws designed not to split the deck board even when driven near the end. Care must still be taken to prevent splitting but will minimize the need to predrill.
Not needing to predrill will save you time. Getting you to enjoying your deck sooner. Till then, happy screwing.
