Choose the Correct Fixing Method for Each Part of Your Deck
Screwing composite decking is appropriate where the product’s installation detail permits it. For NeoTimber® grooved boards, the main deck area uses the specified hidden clip system, while particular final-board, edge and step details can require screw fixing.
The important distinction is not “screws are always wrong”. Clips themselves are secured with screws. The question is whether you are fixing a clip to the joist or driving a screw through the board, and whether that method is approved for the location.
This guide explains the decisions to check before fitting composite decking. Use it alongside the current installation instructions for your exact product. Our decking page provides a broader overview.
In this guide: Understand the methods · Allow movement · Choose clips · Approved face fixing · Drilling and tightening · Existing fixings · FAQs
Clips, Decking Screws and Trim Screws Have Different Roles
Use the correct component for the fixing detail rather than treating all screws as interchangeable.
Match the fixing to its intended role:
| Component | Typical role within the specified system |
|---|---|
| Starter clip | Secures an approved starting edge to the frame. |
| Intermediate hidden clip | Engages board-edge grooves and fixes to the supporting joist. |
| Decking screw | Secures boards at approved face-fixed or edge-fixed details. |
| Trim screw | Attaches specified decorative finishing components. |
A screw sold for a trim is not automatically suitable for a tread board, and a generic timber screw is not automatically compatible with a composite system. The supporting joist material also affects the fixing selection.
Why the Fixing Method Matters
Composite boards expand and contract with temperature changes. The installation needs to secure the boards while accommodating the movement specified by the manufacturer.
Replacing the intended clip arrangement with an improvised pattern of face screws can create restraint or stress around fixings. That does not mean every properly designed screw-fixed detail fails; it means the fixing geometry, holes, gaps and support must work together.
Check board-end gaps and clearance around fixed structures separately from side-to-side clip spacing. A clip does not automatically establish the required end gap. Read our expansion and contraction guide before setting out the deck.
Use the Specified Hidden Clips Across the Main Area
NeoTimber’s starter clips and FastClip options form part of the board installation system. Intermediate clips engage the side grooves and are screwed to the supporting frame.
Install them at the required board-to-joist intersections using the specified screws. Check that the board and clip sit correctly rather than forcing the joint closed.
Metal and plastic FastClip options
The 3mm metal FastClip and 6mm plastic FastClip create different side spacings and have different fitting and access details.
Choose according to compatibility and the installation requirements. These gap dimensions are not alternative end-expansion settings. Keep joints clear so water and debris do not become trapped.
When Can You Screw Through a Composite Board?
NeoTimber’s guidance includes screw fixing for certain final-board, edging and step arrangements. Use the exact illustrated method for that detail, including the required support beneath each fixing.
Coloured composite decking screws are intended for approved board and edge-board applications. Decorative trim screws serve a separate purpose.
Do not treat face fixing as a workaround for missing support, incompatible clips or a board that will not sit correctly. Resolve the underlying problem before fastening the surface.
For additional detail, consult the edging guidance and step installation guide.
Pre-Drill and Tighten According to the Product Detail
Where drilling is required, use the specified hole diameter, position and edge distance. A pilot hole for a decking screw and a movement hole for a trim may differ. Do not apply one generic diameter to every component.
- Identify the exact board, screw and supporting material.
- Confirm support beneath the fixing position.
- Mark and drill the required holes before driving the screws.
- Use the correct driver bit and controlled tightening.
- Avoid crushing the surface, stripping the fixing or altering its intended position.
An excessively large hole is not an automatic solution to expansion, and a deeply buried screw head is not evidence of a secure installation. Follow the approved detail rather than improvising.
Use suitable cutting and drilling equipment with appropriate protective measures. Ask the supplier if the instructions do not cover the proposed situation.
What if the Boards Have Already Been Face Fixed?
Compare the installation with the correct product instructions before deciding that every screw needs removing. Some locations may have been fixed correctly, while others need assessment.
Record the board range, fixing locations and any cracks, distortion or movement. If the area is damaged or unstable, restrict access and arrange inspection. Do not add more screws around a defect as a cosmetic repair.
Removing fixings can leave holes or damaged sections, so agree the corrective approach with the installer or supplier. A replacement board may be needed where the existing component cannot be used appropriately.
How does this affect warranty cover?
NeoTimber’s warranty terms require correct installation and include exclusions for improper fitting. Do not assume that approved screw fixing invalidates the warranty, or that every issue has the same coverage outcome. Review the terms for the exact product and circumstances.
Confirm the Detail Before You Fix the Board
Use the hidden clip system where prescribed and the approved screw method where required. This gives a clearer installation approach than either screwing every board down or avoiding all screws.
Review our fixings, clips and fasteners guide or contact NeoTimber® with your board range and proposed detail before proceeding.
Frequently Asked Questions
Can you screw composite decking down?
Yes, where the manufacturer permits that method. NeoTimber® grooved boards use clips across the main area, with screw fixing at specified details.
Do hidden clips still need screws?
Yes. The clip is secured to the frame with the compatible fixing; it is not a screw-free construction system.
Can I use ordinary timber screws?
Do not assume so. Use the specified fixings for the board, component and supporting material.
Does every face-fixed board need the same pilot hole?
No universal size should be assumed. Follow the exact board, screw and detail instructions.
Can I use trim screws for deck boards?
Only if expressly specified. Decorative trim and walking-surface boards have different fixing requirements.
Will screw fixing automatically void my warranty?
Approved screw fixing is part of some installation details. Coverage depends on the product terms and whether the complete installation follows the guidance.
