Decking With Grip Strips: Complete UK Guide

What are decking grip strips?

“Grip strip” is a broad description used for anti-slip products fitted to decking boards. Depending on the system, the strip may be:

• manufactured directly into a new timber board;
• recessed into an existing groove;
• fixed on top of an existing board;
• made from resin and mineral aggregate, aluminium, GRP or another high-friction material.

The purpose is to provide a harder-wearing, higher-friction walking surface than the timber or composite board alone.

How do anti-slip grip strips work?

Most effective systems use a hard mineral aggregate bonded within resin or fixed to a rigid carrier. The exposed aggregate creates many small contact points that interact with footwear, helping to maintain traction when the surrounding board becomes wet.

No strip removes the need for cleaning. Algae, mud, grease, ice and leaves can still cover the anti-slip surface and reduce performance.

Types of decking grip strip

Grip strips for new decking

Where a complete new deck is being installed, factory-applied anti-slip boards normally provide the cleanest result. The timber is machined and the inserts are bonded under controlled production conditions before delivery.

Why factory-applied inserts are often preferable

• The insert depth and position are controlled during manufacture.
• The product arrives ready to install.
• Two- or three-insert layouts can be selected to suit the route.
• The system can be supplied with product-specific test data where available.
• The appearance is more integrated than a surface-mounted strip.

Grip strips for existing decking

Existing decking does not always need to be replaced. If the timber and supporting structure remain sound, retrofit grip strips can create a safer walking route at lower cost and with less disruption than a complete rebuild.

RetroGrip® recessed inserts

RetroGrip® uses a rigid aluminium profile with a resin-and-bauxite aggregate upper surface. The insert is designed for compatible grooved timber decking and sits within the existing board profile.

RetroGrip® Tread

RetroGrip® Tread is surface mounted and may be more suitable where the board does not have a compatible groove, where a clearly visible route is needed or where rapid mechanical installation is preferred.

Benefits and limitations of decking with grip strips

How is the slip resistance of grip strips tested?

In the UK, the pendulum tester is commonly used to assess pedestrian slip resistance. It produces a Pendulum Test Value, or PTV. Higher values generally indicate lower slip potential.

The result should be considered alongside the test condition, slider, direction, contamination and intended use. A dry value alone is not enough for a deck that will regularly become wet.

See GripDeck’s current published data on the anti-slip test results page.

Should decking use two or three grip strips?

For a standard 145 mm-wide decking board, two inserts are suitable in most general applications. Three may be advisable where the main direction of travel runs along the board length, including:

• bridges;
• boardwalks;
• ramps;
• platforms;
• long access routes.

A central third insert increases the chance that footwear engages a high-friction strip during forward travel. Board width, route design and the project risk assessment should still be considered.

Installing decking grip strips

The exact process depends on the chosen product. Always follow the manufacturer’s instructions rather than assuming that every insert or tread uses the same adhesive, screw or groove dimensions.

Before installation

1. Confirm the deck and substructure are sound.
2. Clean the boards and remove algae, dirt and loose coatings.
3. Measure the board and groove dimensions accurately.
4. Check that the product is suitable for the substrate.
5. Plan the strip positions around fixings, board ends and joints.
6. Confirm whether adhesive, mechanical fixing or both are required.

Important installation principles

• Use corrosion-resistant fixings suitable for exterior use.
• Avoid over-tightening screws through rigid profiles.
• Keep board drainage and ventilation gaps open.
• Do not bridge moving joints unless the product is designed for it.
• Trim cut ends neatly and treat exposed material as instructed.
• Check that no edge or fixing creates a trip hazard.

Can grip strips be fitted to composite decking?

Sometimes, but compatibility must be confirmed. Composite boards vary in wall thickness, capping, hollow structure, expansion behaviour and fixing method. A strip designed for timber grooves should not automatically be installed in composite decking.

Before fitting a surface-mounted system, check:

• the composite manufacturer permits drilling or bonding;
• the screw can obtain adequate purchase without crushing the board;
• the adhesive is compatible with the cap material;
• the strip will not restrict normal thermal movement;
• the installation will not invalidate the board warranty.

Read our guide: Is composite decking slippery?

Where are decking grip strips most useful?

Maintaining decking with grip strips

A sensible maintenance programme protects both the deck and the anti-slip system.

Avoid aggressive pressure washing close to resin, timber fibres or profile edges unless the product instructions allow it.

Grip strip buyer’s checklist