DeckWise WiseGuides 13/64" Gap Deck Board Spacer Guide for Hardwood, Pressure Treated Lumber, Thermal Wood, PVC and Composite Decking Alignment

Why consistent gaps matter

Spacing deck boards evenly is one of those tasks that looks simple until you try it at full scale. On my last build, I put the WiseGuides spacers from DeckWise into service—specifically the fixed 13/64-inch version—and they quickly became part of the flow. They don’t straighten boards or solve lumber quality, but they do one job very well: establish a precise, repeatable gap that stays put while you fasten.

Design and build quality

These are rigid, blade-style spacers with rounded working edges designed to avoid denting and marring, and that’s not just marketing. I drove them between kiln-dried hardwood and soft pressure-treated pine without bruising the fibers. The material feels like a glass-filled nylon—tough, slightly compliant under abuse, and unfazed by taps from a mallet. I yanked a few out with the claw of a hammer when they were stubborn and didn’t see cracking or deformation.

Each spacer has a finger ring that actually helps. With gloves on and sawdust everywhere, being able to hook and pull them out quickly was a small but real time saver. The bright color makes them easy to spot on the deck, which is helpful when you’re leapfrogging spacers down a long run and trying to avoid losing one under a joist bay.

They come in packs of six. For small platforms, that’s enough to work systematically. For anything with 10- to 16-foot boards on 16-inch centers, I wanted at least two packs so I could place spacers at more joists simultaneously and keep the board tracking straight as I moved.

The 13/64-inch gap in practice

At about 0.20 inches, this gap lands in the practical middle for many decking materials. It’s wide enough for composite/PVC manufacturers’ minimum ventilation requirements and for hardwoods that need airflow to shed water and debris, but not so wide that it looks exaggerated.

• Pressure-treated lumber: On new, wet PT, 13/64 will look generous initially and can feel wider as boards dry and shrink. If your PT boards are truly saturated, you might prefer a thinner spacer for aesthetics—but that’s a design choice, not a flaw in the tool. If you accept a slightly wider gap as boards age, this size is very workable.

• Hardwoods (I used cumaru): It’s a sweet spot. Moisture exchange is less dramatic, and the finished look is consistent. The rounded blade edges didn’t crush the grain, even on end grain near cuts.

• Composites/PVC: Most composite guidelines recommend gaps around 3/16 to 1/4 inch depending on temperature. This sits comfortably within that range. On a cool morning install that later saw heat, the spacing remained visually consistent.

• Thermally modified wood: Dimensional movement is reduced compared to conventional softwoods. The fixed 13/64 worked well here, too.

If you need different gaps for different uses (e.g., tighter front porch, wider pool deck), you’ll need a different size spacer. These are single-thickness tools by design.

Workflow and ergonomics

The best way I found to use them:
1. Start the board, then place spacers over each joist or every other joist for shorter runs.
2. Bring the next board into contact with the spacers, clamp as needed, and fasten.
3. Pull the spacers using the rings and leapfrog them forward.

They don’t replace clamping or a board straightener when you’re dealing with a strong crown or twist. They’re equally at home with face-screws or hidden fasteners. With hidden systems, I appreciated that the spacers sit high enough to remain accessible without interfering with the fastener hardware.

Where I wished for a variant was in tight confines—up against a wall ledger, between a post and the last board, or when a joist hanger crowds the edge. A “half-moon” or offset profile would sneak into those spaces more easily. With these, I could usually angle the blade in or tap it gently, but a thinner lead-in or asymmetrical option would improve access.

Accuracy and consistency

Consistency is the whole point, and these deliver. The blade’s thickness is uniform across its length, so once they’re set over multiple joists, boards naturally align to an even reveal. On a 12-foot run, using spacers at six to eight points kept the board from wandering while I fastened. I checked with calipers in a few places out of curiosity; variance was within a few thousandths, which is tighter than any wood movement you’ll see over a day in the sun.

Because they’re rigid, they resist compression that can creep into softer DIY spacers (like wood shims). That rigidity is also what makes them a little stubborn to remove if you drive a board aggressively onto them. The finger ring mitigates that; a light tap backward with a mallet frees them quickly.

Durability

I’m comfortable calling these jobsite-tough. They took hammer taps, prying, and some unintentional stomps without drama. No edges mushroomed, no corners chipped. I’ve used cheaper plastic shims that quickly turned into consumables—these did not. If you build more than one deck a year, the longevity alone makes a case for a dedicated set.

Value and pack size

Six per pack is the main limitation. For decks with longer boards, it’s efficient to have one spacer at each joist bay you’re actively fastening. That usually means two or three packs if you want to avoid leapfrogging constantly. I’d welcome an option with eight or ten spacers per pack. Also, if you’re ordering multiple sizes from the same line, the color-coding is handy; otherwise, it’s simply nice for visibility.

Price-wise, they initially feel steep for “just spacers,” but the combination of accuracy, speed, and durability made the cost easy to justify on my project. If you only need a single deck’s worth and can tolerate a slower pace, you can get by with one pack and leapfrog. If time is money, get two.

What they are—and aren’t

• They are precise, tough, and easy to handle spacers that set a 13/64-inch reveal across hardwood, pressure-treated lumber, thermally modified wood, PVC, and composites.
• They are not a board-bending solution. You’ll still need a bow wrench, cam clamps, or a dedicated straightening tool for warped stock.
• They are not adjustable. If you anticipate switching gap sizes, plan on owning multiple thicknesses.

Practical tips from use

• Use one spacer per joist along the board you’re fastening when you need perfect tracking; otherwise, space them every other joist and leapfrog.
• On hot days with composites, keep spacers shaded or stored off the deck to avoid heat soak. They don’t deform, but cooler tools are easier to handle.
• For tight end-of-run areas, start the spacer at a shallow angle and walk it in with light taps rather than forcing it straight.
• Mark your pack with a permanent marker: 13/64. If you own multiple sizes, this avoids mix-ups mid-project.

Bottom line

The DeckWise WiseGuides spacers do exactly what they promise: deliver a clean, uniform 13/64-inch gap with minimal fuss. The blade profile is kind to decking faces, the finger rings speed removal, and the bright color keeps them from disappearing into the sawdust. Their rigidity and durability set them apart from improvised shims and flimsy knockoffs.

I’d like to see a couple more pieces in the pack and a variant that’s easier to use in tight confines. And if you’re wrestling with crooked boards, know that these aren’t a cure; pair them with a straightening tool. But for ensuring professional-looking, consistent reveals—especially across mixed materials—they’re a reliable, repeatable solution.

Recommendation: I recommend these spacers. They’re accurate, rugged, and genuinely improve speed and consistency on deck builds. Get two packs for longer runs or if you prefer to set multiple joists at once; otherwise, one pack will still serve you well if you don’t mind leapfrogging.