NeoTimber® Composite Decking
Installation & Care Guide
A complete step-by-step guide to installing NeoTimber® composite decking — covering pre-installation handling, all three subframe options, deck board fixing, design considerations and ongoing care.
1. Pre-Installation
Handling Your Decking
- Store boards on a flat, clear surface on wooden battens at 400–500mm spacings to avoid water, dirt or grit damage.
- When storing outside for extended periods, cover boards with protective sheeting.
- Take care when lifting, moving or fitting boards — do not drag, slide or drop them over one another.
- Keep your work area tidy to avoid construction debris scratching board surfaces.
Recommended Tools
Tool Tips: Standard woodworking tools work with NeoTimber® decking. Use carbide-tipped blades for the cleanest cuts; a 40–50 teeth blade is recommended for circular saws. Use a 3mm drill bit for countersinking.
Safety & PPE Required
🥽 Safety Glasses
🧤 Safety Gloves
👕 Long Sleeves
😷 Dust Mask
👟 Safety Footwear
Temperature & Expansion Gaps
Our FastClip system manages side-to-side spacing automatically. Maintain the following gaps at all end-to-end board joins:
| Outside Temperature | End-to-End Gap Required |
|---|---|
| Below 4°C | 6mm |
| Between 4°C – 25°C | 3mm |
| 26°C or over | 1mm |
Colour Characteristics
Will undergo some weathering (lightening-up) in the first 3–6 months as boards react to UV rays. Allow a 5–10% wastage allowance (15% for diagonal patterns).
Equipped with a protective polymer shell for high UV and fade resistance. Colour tone will slightly vary board-to-board to mimic authentic woodgrain.
2. Subframe Installation
All deck boards must be installed directly onto a subframe. Allow a minimum of 35mm space beneath the subframe to ensure adequate airflow. NeoTimber® offers three subframe solutions to suit your project:
Option 1: Composite Joists
A moisture-resistant, long-life subframe alternative to timber. Designed to be installed directly onto a solid, flat concrete base. Joists run perpendicular to the direction of the deck boards at 250–350mm centres. Fix to the concrete base at 500–600mm intervals using a 60mm screw. Leave an 8mm gap between joist joins for expansion.
Best for: Flat, solid concrete bases & patios.
Option 2: Adjustable Pedestals
Used in conjunction with Plastic Lumber joists to elevate a subframe without posts. Five pedestal heights available (18–310mm adjustable range). Lay pedestals in a grid: 250–350mm spacing for Gridline B (deck board span). On roof terraces, do NOT screw into the waterproof membrane — the collective weight holds the system in place.
Best for: Roof terraces, balconies, flat solid foundations.
Option 3: Plastic Joists & Posts
A long-life, moisture-resistant alternative to a traditional timber subframe. Three-phase process: (1) Install plastic post network at 1,000mm intervals, cementing posts with at least 500mm (or ⅓ of post length) below ground. (2) Attach Large Plastic Joists as cross-bearers. (3) Lay joist network at 250–350mm spacings. Use noggins for additional support.
Best for: Uneven ground, raised & low-lying decks on soil.
3. Installing the Deck Boards
NeoTimber® uses a hidden Starter Clip and FastClip system for a clean, professional finish. Joists should be laid at 250–350mm spacings before beginning board installation.
- Fix Starter Clips at the outside edge of your subframe. Starting at the outer edge, attach Starter Clips to each joist using the steel screws provided. Countersink to assist insertion. Position a clip at every joist intersection.
- Seat the first board. Align the grooved channel of your first board with the Starter Clip opening and insert at a slight angle before pushing into place.
- Fix subsequent boards with Metal FastClips. Place the single-pronged side of the FastClip into the exposed groove of the first board. Screw through the countersunk hole into the joist at every intersection. Line up the next board and click its groove onto the clip — repeat across the full area.
- Alternative: Plastic FastClips (6mm). These allow access to any individual board without removing adjacent boards — useful for maintenance access. The same installation principles apply.
- Fix the final board. Place its inner groove into the last FastClips. Pre-drill an oversized pilot hole at 45° into the exposed groove and screw into the joist at 300mm intervals. When the groove is inaccessible, screw directly through the top of the board into the joist (pre-drill first). Use NeoTimber® Coloured Decking Screws for a discreet finish.
Finishing Touches — Trims
Finish exposed edges with a Skirting Trim, Corner Trim, or a combination of both. Pre-drill an oversized pilot hole before screwing to avoid splitting. Leave a minimum 2mm gap between trim ends for expansion. Use NeoTimber® Coloured Trim Screws for a discreet, matched finish.
4. Design Considerations
Picture Framing
A picture frame design creates a border around the perimeter of a deck. Double joists are required in all areas where frame boards run perpendicular to the main run. Two options are available:
Parallel boards follow standard installation. Perpendicular boards are fixed using a Starter Clip on the inside joist, then the exposed groove is screwed into the subframe. Where boards meet at corners, mitre at 45° with a 4mm expansion gap.
Install the NeoTimber® Edge Board perimeter before the main decking run. Fix with Starter Clips on the outside and FastClips on the inside groove. Mitre at 45° at corners with a 4mm expansion gap. Then lay the main decking run as normal.
Decking Steps
Steps must be carefully planned: rise must not exceed 190mm; tread must be 250–450mm deep. A flat, solid concrete or gravel landing pad is recommended for structural support. Two main step construction methods:
Notched pressure-treated timber stringers span from the deck subframe to the base. Space stringers at max 250mm. Anchor at the base with base plates, and fix to the deck with a stringer connector and stair header reinforcement.
Stacked box frames constructed from timber, metal, or NeoTimber® Large Plastic Joists. Infill with joists at 250mm spacings. Secure to the deck subframe at every intersection. NeoTimber® Plastic Posts can be added to the inside edge for extra support.
Cover step treads and risers with NeoTimber® Edge Boards, Deck Boards, Skirting Trim, or Corner Trim — fixed with our clip system or Coloured Decking Screws for a discrete finish.
5. Cleaning & Care Guide
NeoTimber® decking is low-maintenance by design. With occasional care, your boards will continue looking their best year after year.
Need Further Help?
📞 01509 323 170 | ✉️ enquiries@neotimber.com | 🌐 neotimber.com