Pool Decking Options: What to Specify for a Surround, and What the Slip Rating Really Means
Four things attack a pool surround and only one of them is the board. This page works through the pool edge detail, what chlorine and salt water do to everything metal in the build-up, heat underfoot, and the slip question — which is the one most suppliers answer with the wrong test.
On slip we publish the actual document: Intertek report 230625005SHF-001, AS 4586-2013 Appendix D, measured at 15°, classified R10, on profile ZSGJ138H23A. That is the shod wet method. The barefoot wet method is DIN 51097, we have not tested to it yet, and we will test the profile your project intends to use if the specification calls for it — cost up front, credited in full against the order.
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R10, shod wet
Intertek 230625005SHF-001, AS 4586 App. D
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Testing on request
On your profile, credited against the order
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4-sided cap
Back and edges included, co-extruded
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350 mm max
Joist centres for 140 × 23 mm
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MOQ 70 m²
Most single pool surrounds reach it
What Actually Attacks a Pool Deck
Four things, and the board is only one of them. Most pool decking comparisons only discuss the first.
1. The surface, when it is wet and walked barefoot
This is the question everyone asks and almost nobody answers correctly, because three unrelated test systems are involved and a result under one says nothing about the others. There is a chart below, and then a straight statement of which one we have tested to.
2. The water, on everything metal
Chlorinated or salt-chlorinated water splashes out and evaporates, concentrating as it goes. Wood-plastic composite is not metal and does not corrode — but the joists, the clips, the screws and the coping anchors are, and they sit where the splash lands. On a pool surround the fixings usually fail before the surface does.
3. The sun, on bare feet
A dark board in direct sun gets hot enough to be unpleasant underfoot. This is not a defect, it is physics, and it applies to stone and concrete too — but it is a real source of complaint at pools specifically, and it is decided at colour selection, not at installation.
4. Movement, at the one place it cannot be absorbed
Composite expands and contracts with temperature. Around a pool the deck meets a coping stone that does not move with it. If the board is packed tight against the coping, something has to give. That junction is detailed below.
Pool Edge Detail: Coping, Expansion and Where the Fall Goes
The three things this section has to get right are the expansion gap at the coping, the direction of the fall, and the fact that the fall is formed in the substrate rather than in the deck.
Boards drain through their own gaps, so the deck itself is laid level along its length — what needs the fall is the surface underneath, running away from the water. The gap at the coping is a working allowance, not a tolerance: leave the side, end and perimeter allowances for the profile and for your local temperature range. Pedestal heights shown indicatively; spacing and joist section are an engineer's decision.
Chlorine and Salt Water: Component by Component
The middle column is general material behaviour, not our test data. Read the third column as what to settle before ordering.
| Component | What pool water does to it | What to settle |
|---|---|---|
| Composite board | Nothing structural. Deposits left by evaporating splash are a cleaning task | Colour, because of heat underfoot — and slip, see below |
| Clips and screws | The smallest sections in the build-up, sitting exactly where splash lands and dries | Fixing grade, and that it suits a chlorinated or salt-chlorinated environment |
| Steel joist or keel | Zinc is a sacrificial coating and is consumed faster where chloride concentrates | Coating class, or substitute a different material |
| Aluminium joist or keel | Does not rust, but is vulnerable to galvanic attack against dissimilar metals and to water standing in crevices | Alloy, isolation from other metals, and whether crevices drain |
| Coping anchors and edge trim | Hidden, and the most disruptive to replace because the coping has to come up | Specified with the pool, not with the deck |
| Warranty position | Chemical corrosion is an <strong>explicit exclusion</strong> in our board warranty | Read the clause before you buy — it is set out further down |
Non Slip Pool Deck: Which Test Actually Applies
A pool surround is walked barefoot and wet. That is one specific test method, and it is not the one most suppliers quote at you. Find your case, then read what we have tested to.
There is no conversion between the three systems. An R value cannot be turned into a Class, and neither can be turned into a PTV — so a supplier quoting “R11, suitable for pool surrounds” is answering a shod question with a barefoot one. We publish the report for the method we have tested, and we will test to either of the other two on the profile your project intends to use where the specification calls for it.
🔬What we have tested, and how we get you the rest
We hold a third-party slip report and we publish its number: Intertek 230625005SHF-001, AS 4586-2013 Appendix D, oil-wet ramp walked in shoes, measured at 15° — classified R10, mid-band in the 10–19° range rather than scraping in at the bottom. Profile ZSGJ138H23A. Laboratory, standard, angle, profile and date, all checkable. Ask every supplier on your shortlist for the same five things.
That method covers the shod wet parts of a pool complex — plant routes, service access, changing-room approaches. The barefoot wet surround is classified under DIN 51097, and the UK pendulum route is BS 7976. We have not tested to those two yet, and we are not going to present an R value as though it answered them.
If your specification names DIN 51097 or a PTV, that is a testing job, not a dead end. We arrange it on the exact profile your project intends to use, you pay the cost up front, and we credit it in full against the order. Raise it at design stage and it fits inside a normal programme — raise it at inspection and it does not. Tell us the clause and we will come back with the cost and the lead time before you commit to anything.
Pool Decking Options Compared
Composite against the three materials it is usually specified against. Judged on what matters at a pool rather than on a showroom sample.
| Composite (ours) | Porcelain or stone | Poured concrete | Timber | |
|---|---|---|---|---|
| Barefoot slip evidence | △ R10 shod-wet held and published; barefoot class tested on request | ✓ Usually published, A/B/C and R value both | △ Depends entirely on the finish applied | ✗ Rarely classified |
| Splinters underfoot | ✓ None | ✓ None | ✓ None | ✗ Develops with age — the main reason pools move away from timber |
| Heat underfoot in sun | △ Dark colours get hot; light colours much less so | ✗ Stone and porcelain get very hot | ✗ Hot | △ Coolest of the four |
| Chlorine splash on the surface | ✓ Rinse off | ✓ Rinse off | △ Can etch or stain | ✗ Degrades the finish |
| Annual closure for maintenance | ✓ None — wash down only | ✓ None | △ Sealing on a cycle | ✗ Sanding and re-oiling, and the season is when you cannot close |
| Movement at the coping | △ Needs a designed expansion allowance | ✓ Small | ✓ Small, but cracks instead | △ Moves with moisture as well as heat |
| Repairing one damaged area | ✓ Lift the clips, swap the board | △ Colour match on a discontinued batch | ✗ Patch is always visible | ✓ Swap the board |
| Fixings in the splash zone | △ Metal, and the real vulnerability | △ Metal | ✓ None | △ Metal |
Parts List for a Poolside Deck
Quantities from the estimator below; full specifications on each product page.
| Component | ||
|---|---|---|
| Co-extrusion Decking Board23 × 138 mm · 15-year stepped cover Capped on four sides including back and edges — no uncapped face left where splash sits. Profile ZSGJ138H23A, the one our R10 shod-wet result was measured on. For a pool we would specify a capped board and a light colour. | Spec → | |
| Co-extrusion Wide Board23 × 148 mm · 15-year stepped cover Wider face, fewer joint lines across an open surround. Same build-up height as the 138 mm board. | Spec → | |
| Co-extrusion Deck TileDirect-lay · no bearers beneath Lays straight onto an existing concrete surround where there is not enough height for a framed build-up. The usual route for refurbishing a pool deck without lifting the coping. The R10 belongs to the board profile, so a classification on the tile itself is a test we arrange on request. | Spec → | |
| Adjustable Decking Support8,000 N · five ranges 24–175 mm Levels the deck over an existing fall without cutting into the substrate. Component working load, not a platform capacity. | Spec → | |
| Aluminium Keel350 mm max centres No rust mechanism, which matters in a splash zone. Galvanic compatibility with your fixings has to be checked rather than assumed. | Spec → |
Estimate Quantity for a Pool Surround
A surround is usually a band around a rectangle rather than a solid area, so enter the deck area you have actually measured. Quantity is calculated from the 145 mm effective coverage width, not the nominal board width — that difference is the usual reason a container arrives short.
Evidence for a Pool Surround Specification
Everything on the left has a reference number you can check. Everything on the right can be tested on the specific profile your project intends to use — cost paid up front and credited in full against the order. Raise it at design stage and it fits inside a normal programme.
Tested and documented
- R10 shod-wet slip, profile ZSGJ138H23A — Intertek 230625005SHF-001, AS 4586-2013 Appendix D, measured at 15°
- ISO 9001 and ISO 14001, valid to April 2027
- CE marking under CPR — M.2024.206.C97619, UDEM International Certification, a notified body, valid to 11 Mar 2029
- Stepped warranty schedule in writing — 15 years capped, 10 years classic, from signature at the destination port
Tested on request, credited against the order
- DIN 51097 barefoot wet classification — the method that applies to the surround itself
- BS 7976 pendulum PTV, the route most UK specifications take
- EN 13501-1 reaction to fire
- Immersion, leaching, salt-spray or accelerated weathering data
- A classification on the tile or the classic range — the R10 belongs to the co-extruded board profile
Above-Ground Pools: What Changes
A deck built around a free-standing pool is a different structure from a surround around an in-ground pool, and one rule dominates it.
The deck is a free-standing structure that happens to sit next to a pool. It carries none of its load onto the pool wall, and it is set back far enough that the wall can flex as the pool fills and empties. Everything else on this page still applies — expansion, fixings in the splash zone, slip evidence — plus stair geometry, because access stairs to a raised deck are regulated stairs. Our stair treads are a separate moulded profile with a tighter 300 mm support spacing.
Pool Decking: Common Questions
Slip and safety
Is composite decking non slip for a pool deck?
We publish the report rather than the adjective. Intertek 230625005SHF-001, AS 4586-2013 Appendix D, oil-wet ramp walked in shoes, measured at 15°, classified R10 on profile ZSGJ138H23A — mid-band in the 10–19° range. That is the shod wet method and it covers the shod wet parts of a pool complex. The barefoot wet surround is classified under DIN 51097; we have not tested to that method yet and we will arrange it on your profile if the specification calls for it, with the cost credited against your order. If a supplier says non slip without naming a method, a profile and a report number, ask for those three things.
A supplier quoted R11 and said it suits pool surrounds. Is that valid?
R values come from the shod ramp test; pool surrounds are normally specified against the barefoot test, which produces Class A, B or C. There is no conversion between them, so an R11 result is real evidence of something — just not of barefoot performance. Ask which profile, which laboratory, which standard and what date, then ask specifically whether a DIN 51097 class exists. Our own answer to those five questions is Intertek 230625005SHF-001, AS 4586-2013 Appendix D, 15°, R10, ZSGJ138H23A — and for DIN 51097, tested on request rather than already in hand.
Does the R10 cover the tiles and the other boards?
No, and that is worth being exact about. The result belongs to the profile that went on the ramp — ZSGJ138H23A. It does not automatically extend to the tiles, the wide board, the stair tread or the classic range. Where a project needs a classification on one of those specifically, that profile gets tested. A supplier who quotes one report across a whole catalogue is telling you something about their paperwork, not about the product you are buying.
What about a non slip coating applied afterwards?
That is the coating manufacturer's classification rather than ours, and it is theirs that your specification would be judged against. We do not supply coatings and we have no data on how one behaves on our surface. If the aim is a documented barefoot classification, testing the board itself is the more direct route and we will arrange it.
Water, heat and detailing
Will chlorine or salt water damage the boards?
Wood-plastic composite is not metal and does not corrode. The vulnerability in a pool build-up is everything metal — clips, screws, joists, coping anchors — sitting where splash lands and evaporates. Specify those for the environment. Note also that chemical corrosion is an explicit exclusion in our board warranty; we would rather you read that now than discover it at claim stage.
Do the boards get too hot to walk on?
A dark board in direct sun gets hot, as stone and concrete do. Colour is the lever — light colours are markedly cooler than charcoal. We have no surface-temperature test data, so we are describing physics rather than quoting a figure, and for a barefoot area we would specify a light colour.
How do you detail the junction with the coping?
Leave a designed expansion allowance between the boards and the coping stone. The deck moves with temperature and the coping does not, so packing them tight is what causes lifting later. The section diagram above shows the gap, the fall and where the fall is actually formed.
Which way should the deck fall?
Away from the water, and the fall is formed in the substrate rather than in the deck. Boards laid with open gaps drain through the gaps, so the deck surface itself does not need a slope along its length — what carries the water away is the surface underneath it.
Specification and supply
What joist spacing should a pool deck use?
350 mm maximum centres for the 140 × 23 mm board. Tighten where the surround carries concentrated loads — a diving board surround, a plant access route, or anywhere a lifeguard chair or heavy furniture stands.
What do the boards weigh?
22.4 kg/m² for the 140 × 23 mm board, about 0.22 kN/m², derived from 3.25 kg per linear metre at a 145 mm effective coverage width. That is boards only — joists, pedestals and anything the deck carries are additional.
Can we lay over an existing concrete surround?
Often yes, using direct-lay tiles where there is not enough height for a framed build-up, or a pedestal build-up where there is. The constraint is usually the level at the coping and at any door threshold, so measure the height you have before choosing between them.
What is the minimum order?
70 m² for decking. A typical private pool surround is in that range or above it, so a single project usually reaches it. It is well below a full container.
What is the lead time, and can we see the boards?
20 days production for standard catalogue sections. Samples are free — you cover the courier, and we credit it against your first order. For a pool project, wetting a sample and standing on it barefoot tells you more than any brochure, and we would rather you did that than take a rating on trust.
Send the pool details
Surround area, whether the pool is in-ground or above-ground, what is underneath, the height you have at the coping and at any threshold, whether your specification names a slip classification, and the destination port. We come back with a board and substructure list, a quantity take-off, and what testing if any the specification would require.
Send the clause, and we will tell you what it takes
If your specification names a slip classification, quote it to us. We will tell you what we already hold, what has to be tested, what the test costs and how long it takes — and the cost comes back to you against the order.