Installation

Composite decking installation, done clean.

Tarimatec decking sits on a concealed aluminium sub-frame with hidden clips — no face screws, no splinters, and a predictable, warranty-grade install.

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The system

Concealed sub-frame, hidden clips.

Boards fix to a Rastrel A aluminium sub-frame (30 × 50 mm, AW-6005 T6) with concealed clips, so fasteners never show on the surface. The result is a flush, splinter-free deck with consistent board gaps and a clean perimeter — and boards that can be lifted and re-laid if access is ever needed.

Key requirements

Build it to warranty standard.

Joist spacing

Correct sub-frame centres for the profile and span.

Expansion gaps

End and side gaps sized for thermal movement.

Ventilation & drainage

Airflow and fall beneath the deck to shed water.

Edge & perimeter

Fascia, start and finish profiles for a clean edge.

Before you start

The technical manual is the source of truth.

Tarimatec's 25-year warranty is conditional on installing to the technical manual — joist spacing, fixing patterns, expansion gaps, drainage, ventilation and substrate requirements for both Hollow and Solid profiles. Zinodeck supplies the manual and supports builders through their first installs.

Always follow the current Tarimatec technical manual and local building codes (NBC and provincial).

The method

How composite decking is installed, step by step

Every Tarimatec deck follows the same concealed-fixing sequence. Exact centres, gap sizes and fixing patterns come from the current Tarimatec technical manual for your profile — the steps below are the shape of the job, not a substitute for it.

Set out the aluminium sub-frame

Lay the Rastrel A aluminium joists (AW-6005 T6) over a firm, free-draining base, at the joist centres specified for your board profile and span. The sub-frame carries the deck instead of timber, so it will not rot, twist or feed the frost cycle.

Level and set falls on pedestals or packers

Bring the frame to level and build in a slight fall so surface and sub-deck water drains away rather than pooling. On roofs, balconies and paving, adjustable pedestals let you tune height and fall without cutting into the structure below.

Fix the starter clips and first board

Set the perimeter start clips, then position the first board true to your reference line. A straight, square first board sets the gap and alignment for the whole deck.

Lay boards on hidden clips

Work across the deck fixing each board with concealed clips into the aluminium joists. No screws pierce the board face, so the finished surface stays flush and splinter-free — and individual boards can be lifted and re-laid later if access is needed.

Hold the expansion gaps

Keep the specified end and side gaps as you go. Composite boards move with temperature, so consistent gaps let them expand and contract without lifting or buckling — the single most important detail in a cold climate.

Keep the cavity ventilated and draining

Maintain airflow and a clear drainage path beneath the deck. A ventilated, free-draining cavity keeps moisture from being trapped against the underside and helps the deck shed meltwater through the freeze-thaw season.

Finish the edges and perimeter

Close the deck with fascia, start and finish profiles for a clean, continuous edge. Check gaps, alignment and fixings against the technical manual before sign-off.

Canadian conditions

Installing for freeze-thaw and Canadian winters

A deck in Canada is built and detailed for hundreds of freeze-thaw cycles, snow load and meltwater — not just a summer afternoon. The installation choices that matter most in this climate are expansion, drainage and ventilation.

Expansion gaps for thermal movement

Wide temperature swings between summer and a Canadian winter mean boards expand and contract more here than in mild climates. Setting the manual's end and side gaps — and never pinching boards at the perimeter — is what prevents lifting and buckling.

Drainage and falls that shed meltwater

Build in a fall so snowmelt and rain drain off the surface and out of the cavity instead of sitting and re-freezing. Standing water and ice are what stress fixings and framing through the freeze-thaw season.

Ventilation under the deck

An open, ventilated cavity lets the underside dry and lets trapped moisture escape. The aluminium sub-frame helps here — it will not absorb water or rot the way a timber frame can in a wet, freezing climate.

A frame that survives the frost cycle

Boards fix to a concealed aluminium sub-frame rather than wood, so the structure itself does not swell, split or twist as it freezes and thaws — a key reason the system holds its line over Canadian seasons.

Frost depth, footings and ground preparation follow the National Building Code of Canada and your provincial and municipal requirements. Confirm details with your builder.

What you need

Materials and tools for the install

Tarimatec is a system: the boards, the aluminium sub-frame and the concealed fixings are designed to work together. A typical install draws on the following — your exact schedule of components comes from the technical manual and your project take-off.

Tarimatec boards — Hollow or Solid profile, in your chosen colour from the range.

Rastrel A aluminium sub-frame — 30 × 50 mm AW-6005 T6 joists as the structural base.

Concealed clips and fixings — start clips, intermediate hidden clips and the matching screws.

Pedestals or packers — for levelling and setting falls, especially on roofs, balconies and hard surfaces.

Edge and finishing profiles — fascia, start and finish trims for a clean perimeter.

Standard site tools — saw with a suitable blade, drill/driver, spacers, level, square, tape and PPE.

Best practice

Common installation mistakes to avoid

Pinching the expansion gaps

Closing up end or side gaps to “tidy” the deck is the most common cause of lifting and buckling. Hold the specified gaps everywhere, including at the perimeter and around fixed obstacles.

Wrong joist spacing

Sub-frame centres set too wide for the profile leave boards feeling soft underfoot. Use the centres in the technical manual for your board and span.

No fall or trapped water

A dead-flat deck with no drainage path holds water in the cavity, which re-freezes and stresses the build. Always set a fall and keep the cavity clear.

Face-screwing the boards

Tarimatec is a concealed-clip system. Screwing through the board face defeats the hidden-fixing detail and can void the warranty — use the specified clips.

FAQ

Composite decking installation questions

How is Tarimatec composite decking fixed down?

It fixes to a concealed aluminium sub-frame using hidden clips, so no screws show on the board surface. The result is a flush, splinter-free deck, and boards can be lifted and re-laid if access beneath is ever needed.

Do you need expansion gaps when installing composite decking?

Yes. Composite boards expand and contract with temperature, so end and side expansion gaps are essential — especially in Canada's freeze-thaw climate. Follow the gap sizes in the current Tarimatec technical manual for your profile.

Can Tarimatec decking be installed over concrete or a roof?

Yes. The aluminium sub-frame can sit on adjustable pedestals or packers over concrete, paving, balconies and roofs, letting you set level and falls without cutting into the structure below. Confirm loadings and waterproofing with your builder.

Does the installation affect the 25-year warranty?

Yes. Tarimatec's 25-year warranty is conditional on installing to the technical manual — joist spacing, fixing pattern, expansion gaps, drainage and ventilation. Using a builder who follows the manual protects the warranty.

Can I install a Tarimatec deck myself?

The concealed-clip system is designed to be straightforward for an experienced installer, but a warranty-grade result depends on correct sub-frame, gaps and drainage. Zinodeck can connect you with a builder and supplies the technical manual and support for first installs.

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