Did you know that more than 6,500 injuries happen every year because of decks collapsing? And most of these accidents happen because of structural issues.
One way to make sure your deck is structurally sound is by using decking screws the right way. If you want to build a deck that’s sturdy and safe for your family, here are the common mistakes to avoid when using decking screws.
Mistake 1: Using the Wrong Type and Size of Decking Screws
Using the wrong type and size of fasteners to fasten your decking components can result in unsafe decks. This mistake can also lead to unnecessary costs and a less attractive deck.
Using the wrong size of decking fasteners can lead to structural issues. If the screw heads are too small, this can result in inadequate holding force, especially in softwoods. If screws are too short, they can pull loose as the boards move.
As to selecting the correct type of decking fastener, there are two major factors to consider: The decking material, and the prevailing environmental conditions.
Solution:
Size
The most common sizes for decking screws are the #10 x 2½” and #10 x 3″ screws.
Here’s a simple guideline for picking the right screw lengths: The length needs to be about three times the thickness of the wood that’s being attached to the base or framework. Therefore, the right length screw to use for attaching a 1” deck board is 3”.
Screw Material to Match Environmental Conditions
Plain and simply, the best all-round screws are stainless steel decking screws.
Most decking specialists prefer to use stainless steel deck screws. Mainly because they are far more durable than nails or low grade coated fasteners. They will not corrode or rust, leaving ugly stains on your deck.
Stainless steel deck fasteners are also best for pressure-treated wood. These screws resist the chemicals used in the treatment process and the initial increased moisture content of the wood.
304-grade decking screws are ideal for almost all applications. However, if you’re living near the coast, use the 316-grade stainless steel decking screws for a durable, safe deck.
Stainless steel decking screws might cost a little more than traditional ones, but the advantages, in the long run, make it absolutely worth it.
Type of Screw to Match Decking Material Being Used
- Pressure Treated Softwoods such as Pine and Cedar require a screw with a suitably sized head to ensure sufficient down-force with disappearing into the deck board! These are perfect: #10 x 2.5’’ and #10 x 3” 316 stainless steel screws.
- Hardwoods such as iPe, Cumaru and Teak are more dense and more stable, and can therefore use a screw with a slightly smaller head. This also makes them less conspicuous for a sleeker look. For the best results, use Simpson Strong-Tie’s Hardwood Decking Screw.
- Composite decking requires a very specific screw type, and we highly recommend the following: Simpson Strong-Tie’s Deck-Drive™ DCSD Collated Composite-to-Steel Screws.
Mistake 2: Not Pre-Drilling Holes
Some people believe that pre-drilling holes is not necessary since modern screws come with self-drilling tips, and indeed in many cases this is indeed so.
But in certain cases, and especially when working with hardwoods and screws at the ends of boards, it is the better option. Cracked or split deck boards are dangerous, as are screws set proud of the deck surface.
Solution:
We highly recommend the Starborn Smart-Bit. It’s a pre-drilling and countersinking tool, making it quick and easy to achieve a clean and professional finish.
Before you start pre-drilling, mark the spots where you plan on placing the holes. This ensures your spacing is accurate and consistent, making for a very pleasing finished product.
Mistake 3: Over-tightening
Over-tightening screws can cause the head to pull beneath the wood’s surface, which is unattractive and inconsistent to start with, but worse is that it allows water to pool in the decking board which ultimately can lead to rotting.
Solution:
Use a drill with torque control, or a driver that incorporates a depth control setting. I prefer using the former as it gives a better feel, but a depth control is more ‘set and forget’ and does definitely speed things up.
Aside from using the right tools and bits and adjusting the clutch setting, practice with spare materials first. This gives you a feel for the right amount of tightness without risking damage to your decking materials.
Mistake 4: Using the Wrong Bit
Using the wrong bit to drive screws can result in several problems. This mistake can result in head stripping, cam-out, or inefficient torque transfer which leads to loose and lifting deck boards.
Solution:
Look at the shape of the screw head. Common types include Phillips, Pozidriv, Torx, and Robertson (square).
Choose a bit that exactly matches the screw head. This goes beyond just the basic shape—for example, there are several sizes of Phillips and Torx heads.
Harder decking materials might require more torque, so select a drive system that can handle this. We highly recommend the Torx or Star-drive system for all applications.
Mistake 5: Not Allowing for Natural Movement in Decking
Decks are exposed to a range of weather conditions that cause wood to expand and contract. Furthermore, pressure treated decking WILL shrink after installation.
Solution:
One of the most important considerations in building a deck is the joist spacing. This can vary depending on what material is used for the decking, but consult the manufacturer, as well as establish the requirements as specified in your local building code.
Joists spaced too far apart can lead to warping and twisting which is both unsightly and a dangerous tripping hazard. Even worse, planks with insufficient support could fail completely underfoot, causing severe injury.
Correctly spaced joists will hold the decking soundly in place, creating a solid and safe surface for years to come.
Another factor to consider is the spacing between the planks. Plank spacing is also very important, as spacing too close together will cause boards to touch during the wet seasons, placing tremendous strain on the structure and the fasteners.
Pressure treated pine on the other hand is installed with almost no gap, as the planks will dry out after installation and shrink, creating a suitable spacing. However, set it too big initially and high heeled shoes start wedging through, and your favorite Sudoku pen may never be seen again, gone forever through the gap! Again, consult the manufacturer for best practice.
Use Decking Fasteners the Right Way to Build a Safer Deck
Every homeowner wants their family to chill on a deck that’s safe and visually appealing. You can use the most expensive wood or composite materials, but if you’re not using the screws correctly, you won’t achieve the deck you’ve envisioned.
Before starting your decking project, make sure you are familiar with both the proper techniques and types and sizes of screws available to save yourself from headaches and unnecessary costs.