+ 31 33 469 1037

DeckWise® ExtremeKD® Invisible Terrace Fixing

Invisible Hardwood Terrace Fixing Clip (6,4 mm)

Use with Kiln Dried Timber, Thermal Wood & Composites

deckwise extremekd hardwood clip grey - front view
deckwise extremekd hardwood clip grey - back view
Pick from our line of black painted head trim-head screws or Self-Drilling/Heat-Treated screws to be included with your DeckWise® Invisible Fixing Clip Kits (185 count)
Extreme® Ipe Clip® Series - U.S. Patent Numbers 8,464,488 and 8,806,829. Original, “round”, STANDARD Ipe Clip® - U.S. Patent No. D470,039.

Product Features:

  • Integrated spacer wedge uniformly spaces timber planks at 6,4 mm
  • Polyethylene shell and high hardness black oxide stainless steel insert
  • Suitable for kiln dried hardwoods, thermo wood, composite, or PVC planks
  • Permits kiln dried hardwood expansion on width
  • Black oxide coating adds anti corrosion
  • Permits PVC and composite movement on length
  • Distinctive design enables for more endurance in edge-groove planks while maximizing hold-down area
  • Polyethylene casing resistant to harmful UV rays
  • Hollow spacer wedge legs act as a shock absorber
  • 3 Color Options to match terrace material
  • Screwing into planks onto joist sleepers at 45° angle
  • Limited Warranty
  • Premium American Made & U.S. patented
  Dealer Resource Portal   Timber Specie Chart

fastener free ipe surface constructed with deckwise clip
deckwise hidden deck fasteners create smooth beautiful surfaces
luxurious hardwood terrace built with deckwise fixings

Timber Planks Stay in Place

Perfect Plank Gap Spacing & Position

deckwise hidden hardwood fastener clip spacing diagram

1. Direction of plank expansion

2. Direction of plank contraction

3. Top side of the terrace planks

4. Screwed side of the planks

What makes our U.S. patented side-mount concealed fixing clip unique is that, only one side of the plank is secured to the underlying sleeper. This allows the opposite side of plank to move naturally with contraction and expansion. This simple fixing technique guarantees steady and even gap spacing between planks over time as well as end-to-end planks.

ExtremeKD® Hardness Allows for Expansion of Planks

Polyethylene Material Guarantees Long-Lasting Performance

deckwise hidden hardwood fastener stainless steel insert

1. Hardened stainless steel reinforcing insert

  • Guarantees exact screw positioning and prevents over driving
  • Coated with black oxide for long lasting anti corrosion
  • High quality hardened stainless steel reinforcing insert

2. Polyethylene Plastic Resin Square Shape

  • U.S. Patented fixing biscuit shape allows more contact with wood grooves
  • Spacer wedges return to original size after timber expansion
  • Casing is injection molded polyethylene resin for toughness

Designed for hardwood terraces, the color of the plastic resin also works to further camouflage and conceal our invisible terrace fixings between the plank gaps for a concealed fixing method. Also perfect for thermally treated woods!

Our strong stainless steel insert firmly holds planks to sleepers (up to 3X more hold-down strength than other slot mount fixings), eliminating any chance stainless steel screws will pull through the fixing as the imported timber expands.

Incorporated Spacer Wedge Leg

Automatic 6,4mm Gap Spacing Between Plank Timbers

deckwise extremekd hardwood clip grey - back view

1. Hollow spacer wedge leg on the ExtremeKD® absorbs the movement of timber planks and returns to its original shape.

2. The 6,4mm spacer wedge guarantees proper spacing between planks. (Careful attention must be made towards the degree of acclimation to the job site prior to installation; species of wood used; the plank width; and weather climate conditions.)

3. U.S. patented design guarantees higher strength of the fixing during installation.

4. Use With Exotic Hardwoods, Thermally Modified Woods and Composites.

DeckWise ExtremeKD collapsing legs

Hollow leg acts as a shock absorber

Identical Plank Gap Spacing

High-Quality Polyethylene Plastic

Fixing Dimensions

deckwise extremekd hardwood clip dimensions

Hardwood Clip Construction

Material Stainless Steel Insert Available Color
Polyethylene 22,4 x 22,4 x ,9mm deckwise hardwood clips

Timber Compatibility

Air-Dried Timber Kiln-Dried Timber Composite Timber

Resources for Architects & Builders

CSI Divisions & Specs

Enables Expansion on the Width of Kiln-Dried Hardwoods

Screwing fixing clip screws with our standard black trim-head screws is quick and easy. Screw heads hide perfectly in the clip insert for a clean, out of sight finish. Or use the DeckWise® (Heat-Treated Stainless Steel) screws that offer a specially engineered four-sided nail point tip and a serrated thread design. The serration minimizes plank splintering or splitting, even when screwing near the plank edge. Pre-drilling is always recommended.

deckwise extremekd contraction diagram

Screwing Terrace Planks to Sleeper Joists

Terrace fixings are screwed through the timber plank side groove down into sleepers at a 45° angle.

The ability to install stainless steel screws at a 45 degree angle through the hardwood plank greatly increases hold-down power. Studies have proven that, screws have more holding strength when ran at an angle which allows screw threads more grip. This specific method also retains even plank gap spacing while correctly allowing planks to expand and contract with the weather seasons.

  • Promises a strong solid surface, free of face screws
  • Ensures perfect alignment of timber plank gaps
  • Easily install ExtremeKD® fixings from the topside down, not underneath
  • Allows planks to naturally expand and contract on one side only
  • Stainless steel screws affix planks tightly for a long-lasting terrace
  • Self-drilling screws make installations fast and efficient

Enables Expansion/Contraction on the Length of Composite Materials

Driving terrace screws directly down at 90 degrees (through the terrace clip) with PVC and composite materials permits them to move naturally along their length. There is no need to screw through the plank itself. Plank gaps will remain precise and fixings will be concealed inside the timber gaps.

deckwise extremekd expansion diagram
deckwise extremekd composite diagram

DeckWise® ExtremeKD® Installation Specifications

deckwise extreme kd fastener specifications

Plank Compatibility

Plank Thickness Plank Width
*A = Measurement Of Plank Thickness **B = Measurement Of Plank Width

Groove Dimensions

Thickness of Cut Cutting Height Cutting Depth
C = 4mm ***D = (A-4mm)/2 E = 13mm

Plank Spacing

During Installation
****F = 6,4mm

* If utilizing 38,1mm or thicker material, longer screw options may be required than what is generally included with the invisible terrace fixing kit.

** For terraces 20,32cm or wider, the (A) dimension must be at least 38,1mm. Utilizing a wide plank such as this for outdoor terraces will almost certainly generate cupping issues despite of how the material is secured if thicker material is not used.

*** This formula will produce a symmetrical profile that enables you to reverse and/or rotate the plank enabling the best side to be installed.

**** Fixing clip instantaneously produces proper gap spacing when planks are pushed close together in the course of installation.

edge groove board

Reversible/Symmetrical Terrace Planks

Either Side of the Timber Planks Can Be Installed

  • Symmetrical Side Grooves: Timber planks have symmetrical side mount grooves and are centered in the middle of the plank edge.
  • Two Smooth Surfaces: Timber planks have symmetrical side mount grooves and are centered in the middle of the plank edge.
edge groove board profile

No matter what specie of hardwood you choose, they are not always flawless on both sides. Most terrace fixing systems have a side mount profile that does not allow terrace planks to be flipped for the perfect smooth surface. This is not true with our ExtremeKD® invisible terrace fixing clips because we allow for an edge groove that is symmetrical on both sides.

Perhaps there is a blemish on a portion of a timber plank? Simply reverse the plank and install the best looking side face up. Because our system utilizes either side of the plank, installation time is increased and profits are not lost on planks that cannot be installed.

Ask your timber yard to pre-groove your planks or use a router on the job site to cut the slots for fixings.

Terrace Plank Replacement

Review these steps to replace timber planks

DeckWise® ExtremeKD® invisible terrace clips have the added benefit of easy and simple plank replacements. There is no need to disassemble the terrace just to remove a damaged timber plank. Simply follow this link to view the steps needed in our Plank Replacement Guide.

  Plank Replacement Guide

Available Clip Kit Options

DeckWise® Invisible Clip Fixing kits (185 count) can easily be mixed with alternative combinations of our heat-treated patio screws or trim-head terrace anchoring screws. Invisible Clip Kits may also consist of 3 colours of hardwood clips as well as assorted size spacer wedges for specific terrace installations.

deckwise hardwood clip kit box

Complete Kit

  • (185) DeckWise® ExtremeKD® Invisible Clips
  • (200) 4 x 50mm Stainless Steel T15 - Star Drive Black Screws
  • (12) 9,5mm Tapered Ipe Plugs
  • (1) 3,2mm High Speed Drill Bit
  • (1) T15 Star Driver Tips
  • (3) Spacer Wedges
  • (1) Instruction Sheet

deckwise hardwood clip kit box

7,5L PRO Bucket

  • (555) DeckWise® ExtremeKD® Invisible Clips
  • (600) 4 x 50mm Stainless Steel T15 - Star Drive Black Screws
  • (3) 3,2mm High Speed Drill Bit
  • (3) T15 Star Driver Tips
  • (6) Spacer Wedges
  • (1) Instruction Sheet

deckwise extreme kd hardwood clip
stainless steel decking screw
Stainless Steel Screws
deckwise board gap spacer
Wedge Gap Spacers
t15 driver tip
T15 Star Drive Tip
high speed drill bit
3,2 mm Drill Bit
deckwise hardwood plug
9,5 mm Plugs
deckwise warranty

DeckWise® Invisible Terrace Clip Limited Warranty

To make a DeckWise® product claim, warranty registration form must be completed here:

Limited Warranty
This site uses cookies to help better your experience. By using DeckWise® B.V. you agree to our new privacy policy, cookie policy, & terms, which we encourage you to review.

Request a Quote

submit inquiry  

Please check box, then click verify.

Does your timber supplier carry DeckWise®?

Free €100 Gift Card

  More Info