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Composite decking screws or clips: what to use on composite boards

Updated: October 2026

Before you check out a box of green decking screws for composite boards, settle whose fixing the maker wants. Hollow boards should not take a timber screw through the face. Use the hidden clips or screws in the board maker's guide if the warranty has to stand. The packs in the [decking screws comparison](/hub/screws-and-accessories/decking-screws) are timber and frame fixings. Prices are October 2026 listings, not a lab test. A qualifying purchase through our links can earn a commission at no extra cost to you.

Before you check out a box of green decking screws for composite boards, settle whose fixing the maker wants. Hollow boards should not take a timber screw through the face.

Our top picks

HOME IT HOME IT A4 6 x 100 mm

Best overall

HOME IT HOME IT A4 6 x 100 mm
7.4/10about £13.49
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Forgefix ForgeFix 4.5 x 60 mm

Rank 2

Forgefix ForgeFix 4.5 x 60 mm
9.2/10about £5.84
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TIMCO TIMCO Classic 4.5 x 70 mm

Best value

TIMCO TIMCO Classic 4.5 x 70 mm
8.9/10about £8.50
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On this page
  1. 1.Hollow boards and face screws
  2. 2.Clips, the maker's screws, and the warranty
  3. 3.What this shelf actually sells
  4. 4.If the boards are timber after all

Hollow boards and face screws

Many composite boards are hollow, with chambers inside a thin outer wall. A timber screw then grips only that top wall before it passes into empty space. Ecodek, a UK composite maker, says hollow boards should not be face-screwed: the top can crack, the screw can pull through, and water can sit in the chamber. Two green 60 mm screws at every joist is the TDCA pattern for timber. On hollow composite it is the fixing the maker tells you to avoid.

Clips, the maker's screws, and the warranty

Hidden clips sit in the edge groove and screw to the joist, so neighbouring boards are held with no head on the surface. Start and finish boards often need a different clip. Ecodek notes that warranties often require that brand's own clips or screws. A generic timber screw may hold and still sit outside the warranty. Solid composite is less strict, and some makers sell their own face screws for it. Read the guide that came with the boards before you buy a different fixing.
HOME IT HOME IT A4 6 x 100 mm

Testsieger

HOME IT HOME IT A4 6 x 100 mm
7.4/10about £13.49
View offer

What this shelf actually sells

Every pack in the comparison is a timber or frame fixing: ForgeFix boxes of 200, TIMCO Classic, a Zynthor Torx pack and a METALLIXITY Torx box. None is a composite clip. On the ForgeFix 60 mm listing a shopper asks about composite, and the saved page does not answer. UK reviews there describe timber. The AJ Timber and Zynthor hex screws are for posts and sleepers. HOME IT A4 is sold for decking and cladding, not as a clip, and its size fields disagree. Stainless metal does not fix a hollow board.

If the boards are timber after all

If the boards are solid treated softwood, with no chambers at the cut end, this page no longer applies. Length is at least 2.5 times the board thickness. Green coated carbon steel suits an inland softwood deck, and A4 suits the coast and oak. Those choices are in the decking screws buying guide and on stainless or coated decking screws. Two screws per joist, 25 mm from the ends, pilots and flush heads are in how to screw down decking boards.

Common questions

Can you use normal decking screws on composite decking?
You should not use normal timber decking screws to face-fix hollow composite boards. Ecodek, a UK composite maker, advises against face-screwing hollow boards, because the screw holds only in the thin top wall and can crack it or pull through. Use the hidden clips or screws your board maker specifies, which is also what many composite warranties require.
What is the difference between face screws and hidden clips?
A face screw goes through the top of the board into the joist, leaving a visible head. A hidden clip sits in a groove along the board's edge and is screwed to the joist, holding neighbouring boards without any head on the surface. Composite decking usually uses hidden clips, while timber decking is usually face-screwed.
Can you face-screw solid composite decking boards?
Some makers allow face-fixing of solid composite boards, but usually with their own composite screws, not a generic timber decking screw. Check the installation guide for your boards before you fix them. If the guide names a specific screw or clip, using a different fixing may affect the warranty even if it seems to hold.
Will timber decking screws void a composite decking warranty?
They may. Ecodek notes that composite warranties often require that brand's own clips or screws. Using a generic coated timber screw instead can give the maker grounds to question a claim if boards crack, move or stain. Check your warranty terms and the installation guide before buying fixings from a different brand.
Are stainless decking screws suitable for composite boards?
Stainless steel stops the screw from rusting, but it does not solve the problem of face-screwing a hollow composite board. A stainless timber screw still grips only the thin top wall of a hollow board. Use the fixings your board maker specifies, which may include their own stainless composite screws for solid boards.
Can coach screws be used to fix composite decking?
No. Coach screws, such as 200 mm hex-head screws, are frame fixings for joists, posts and sleepers. Their heads stand proud of the surface, and they are far too large to fix a deck board. Use them for the substructure if the maker allows, and fix the composite boards themselves with the maker's clips or screws.

Related pages

Screws and accessories

Decking screws

Best decking screws for an inland UK softwood deck

Decking screws buying guide for length, metal and drive

How to screw down decking boards and keep them flat

Stainless or coated decking screws for your garden

Sources

Public UK sources on deck fixings, stainless grades, salt spray, permitted development and eye protection. Listing prices and star counts are from the amazon.co.uk extracts kept for this comparison on 15 and 16 October 2026. Prices move.

  1. TDCA, Deck fixings FAQ (retrieved 16 October 2026)
  2. TDCA, Metal fixings (retrieved 16 October 2026)
  3. GOV.UK, Permitted development technical guidance (retrieved 16 October 2026)
  4. BSSA, Stainless steel fasteners (retrieved 16 October 2026)
  5. ISO 9227:2017 (retrieved 16 October 2026)
  6. TIMCO, Salt-spray test reports (retrieved 16 October 2026)
  7. Ecodek, Composite screws and clips (retrieved 16 October 2026)
  8. HSE, Using the right type of PPE (retrieved 16 October 2026)