Knugoua Multi-Thickness Deck Spacers (1/16", 1/8", 3/16", 1/4") Durable ABS Deck Board Spacing Tool for Composite, PVC Pressure Treated Lumber

A simple spacer that keeps decks honest

On projects where precision adds up board after board, I reach for simple aids that enforce consistency. For a recent resurfacing of a pressure-treated deck and a small composite landing, I put the Knugoua deck spacers to work. They’re an X‑shaped, bright‑green set with four common thicknesses—1/16", 1/8", 3/16", and 1/4"—and ten total pieces in the box. Nothing flashy, just a straightforward way to keep gaps consistent while you fasten.

Design and build

Each spacer in the set is a uniform thickness, labeled clearly on both sides so you can grab what you need at a glance. The X shape is more than just convenient to hold. It helps you register boards in both the horizontal and vertical directions. You can straddle a joint so two arms sit between adjacent boards near the top surface and two near the bottom, which subtly nudges boards into plane while you tack them down. The faces include printed screw alignment marks—simple reference targets that give you a quick visual if you’re face‑screwing or pre‑drilling at a consistent offset from the board edge.

They’re ABS plastic, which is the right choice for this kind of tool: durable enough to reuse across projects, not brittle like some cheaper plastics, and they don’t mar finished composite or hardwood surfaces. The bright green is more than a style choice; it’s easy to spot on a busy deck or in the grass when one inevitably drops.

Using the spacers on real decks

I tested the set on three common scenarios:

• A pressure‑treated refacing where the homeowner wanted a tighter 1/8" gap to match an existing section
• A composite landing where the manufacturer called for a 3/16" gap to account for thermal expansion
• A small hardwood stair tread where I wanted a clean 1/16" reveal against a skirt board

In all cases, the workflow is the same. I dry‑fit the next board, slide two spacers in at each joist (one near each edge of the board), gently tap the board to seat it against the spacers, then tack the board with a fastener at each joist. Once the row is locked in, I pull the spacers and move on. With ten spacers, I could bridge three joists at a time comfortably—fine for a solo or two‑person crew—but on a full‑size deck, I’d buy a second set to avoid leap‑frogging constantly.

The X shape helps keep the gaps straight from the board’s top face to its lower edge, which matters if your joists or boards aren’t perfectly flat. With standard single‑leg shims, it’s easy to end up with a tapered gap from over‑clamping or an out‑of‑plane board. These made it easier to keep things plumb while I snugged the boards with a bow wrench.

Accuracy and consistency

Out of the box, my calipers read the thicknesses within a few thousandths of the stated sizes—close enough that any deviation in real‑world use is invisible. On the deck refacing, laying 20 rows across a 12‑by‑16 gave me a clean, uniform pattern. Water sheds as it should, debris doesn’t bridge, and the gaps look intentionally set rather than eyeballed.

I appreciated the screw alignment markings more than I expected. They’re not a substitute for a chalk line on joists, but they do help you keep a consistent edge distance while moving quickly. If you’re pre‑drilling hardwoods, the marks make it easy to align the bit across multiple boards without measuring each time.

Durability and handling

ABS will never compete with aluminum for absolute toughness, but it held up well. After two deck days and a tile backsplash experiment (more on that below), I saw minor abrasion on the thin 1/16" pieces and a hint of mushrooming on the edges where I’d over‑seated a board with a tap from a mallet. None of that affected spacing accuracy. If you avoid using them as prybars, they’ll last through multiple projects.

Heat wasn’t an issue. I left a few on a sun‑baked composite landing in midsummer; they stayed stiff and didn’t deform. Cleaning pitch and dust is as simple as a quick scrape with a putty knife and a rag. The high‑visibility color also means you’re less likely to absent‑mindedly leave one in a gap and discover it only after the last screw is in.

Where they shine—and where they don’t

Strengths:
- The four sizes cover the most common gap requirements for pressure‑treated, composite, PVC, and hardwood decking.
- The X shape actually helps with board registration, not just spacing.
- Clear size labels and alignment marks reduce fumbles and measuring.
- Bright color cuts down on lost tools and speeds retrieval.

Limitations:
- Ten pieces are enough for repairs and small builds, but on a large deck you’ll want more to keep pace.
- As with any plastic spacer, if you crank a clamp or lever a crowbar against them, the thin sizes can deform.
- They’re most useful for face‑fastened or pre‑drilled installations. If you’re using hidden clip systems, you’ll rely on the manufacturer’s spacers more than these.
- The largest size is 1/4". If your design or jurisdiction calls for larger seasonal movement gaps, you’ll need a different solution.

One note on technique: place spacers at each joist, not just at the ends of boards. That keeps the gap consistent despite board curvature, and it prevents over‑tightening at one location from “pinching” another. On cupped or bowed boards, seat the board against spacers with gentle, even pressure; don’t hammer the spacer legs. If your boards are wet (pressure‑treated fresh from the yard), plan your gap accordingly—1/8" can close down as the boards dry, whereas composite may expand and wants the 3/16" or 1/4" on hot installs.

Beyond decking

These are intended for decks, but they work as general spacing tools. I used the 1/8" ones to keep reveals even while installing a cedar privacy screen, and the 1/16" size made clean work of a tile backsplash accent where I wanted a very tight grout line between factory‑rectified pieces. The X shape makes them easy to pull out and reuse on vertical applications without dropping spacers behind finished work.

Value and who they’re for

The set is positioned as a reusable aid, and that’s how it performs. If you’re a DIYer building one deck or refreshing an aging surface, a single set will cover most needs—buy two if your deck is wide or if you want to keep a consistent cadence without moving spacers around. For a pro crew cranking out multiple decks a season, I’d still keep a few sets on hand for punch‑list work, stair details, and non‑clip installations. If you routinely abuse tools or need spacers to double as levers, a metal set or dedicated gauging blocks may suit you better.

Final thoughts and recommendation

The Knugoua deck spacers do exactly what I want a spacer to do: they create reliable, repeatable gaps, help keep boards aligned as I fasten, and speed the overall workflow without introducing fussy steps. The four common sizes cover most decking materials and climates, and the labels and alignment marks shave off small but meaningful bits of setup time. While the ten‑piece count and ABS construction set practical limits—this isn’t a one‑set‑does‑all solution for a large crew—they’re durable enough for multiple projects when used sensibly.

I recommend these spacers for homeowners and pros who need an affordable, reusable way to set consistent gaps across a variety of deck materials. They’re especially good for repairs, small to mid‑size decks, stairs, and detail work where the X shape’s alignment benefits show. If you’re outfitting a big team or you demand a spacer that can take serious leverage, look to a larger count or metal alternative; otherwise, this set is a smart, efficient addition to a deck‑building kit.