Deck planning reference

Deck edge, fascia and stair details

The field of a deck is the easy part. What separates a deck that looks built from one that looks assembled is the perimeter: how the edge is closed, how a hollow board end is finished, how a step is nosed, and how a rooftop deck meets its membrane. Four drawn sections, with the classifications that apply to each.

1. Deck edge with fascia

The fascia hangs from the deck surface and closes the cavity visually without sealing it.

• The fascia profile is 180 × 10 mm, cut from 2,500 mm lengths, so a perimeter take-off is simply the perimeter divided by 2.5 plus a cutting allowance.
• Fascia is a screen, not a seal. Leave the cavity ventilated at both ends of every run. A boxed-in, airtight cavity runs hotter, holds moisture and pushes the boards toward the top of their movement range.
• Gap the fascia at its ends and at corners like any other board. It expands and contracts on the same coefficient as the decking.
• Fix the fascia to the perimeter frame, never to the underside of the deck boards.

2. Hollow board ends and end caps

A hollow board cut to length leaves its cells open. Any end a person can see, touch or sweep into needs closing.

• Cap every exposed end of a hollow board. Open cells collect leaves, grit, insects and standing water, and they read as unfinished from two metres away.
• Where a run of ends faces the same direction, a fascia return across the whole edge is usually tidier than a row of individual caps.
• The solid profile, 149.2 × 20 mm, has no voids and needs no caps. That is one of the reasons it is worth considering for stair treads and exposed edges.
• Cut ends still need the end gap for their board length. Capping does not remove the need for clearance.

3. Stair treads and nosings

Two steps in section. The tread overhangs the riser by a constant amount; the riser is clad in the fascia profile so the stair reads as one material.

• Tarimatec decking is classified Class 3 (R11) for slip resistance to UNE-ENV 12633, which is what makes it usable around pools and on steps. Class 3 is a surface classification, not a substitute for good detailing: a stair still needs an even nosing, adequate lighting and a handrail.
• Support every tread within the same 350 mm rule as the field. A tread that spans further than the deck does will feel different underfoot, and a stair is exactly where people notice.
• The solid profile is worth specifying for treads. It has no open cells to cap at each end, and its higher impact resistance, above 20 J to UNE-EN ISO 477 against above 7 J for the hollow board, is meaningful on a step.
• Rise, going, nosing projection, handrail height and guard requirements come from the National Building Code and your provincial and municipal amendments. Nothing on this page overrides them.

4. Rooftop and terrace edges

Rooftop build-up on adjustable pedestals. The deck floats above the membrane; water runs under it, not across it.

• The hollow Tarimatec profile carries a Broof(t1) roof covering classification to UNE-ENV 1187, and the material's reaction to fire is Bfl-s1 to UNE-EN 13501-1. Quote both to the authority having jurisdiction with the test reports rather than paraphrasing them.
• Nothing penetrates the membrane. Adjustable pedestals sit on it and take the falls out of the finished surface, so the deck reads level while the roof still drains.
• Keep the perimeter open. A gap at every upstand and parapet lets the cavity drain and ventilate, and gives the boards their expansion clearance at the same time.
• Rooftop assemblies carry wind uplift, drainage and maintenance-access requirements that a decking detail cannot answer. Get the build-up designed, and keep access panels where the drains are.

Details this page does not cover

Handrails, guards, gates, lighting, drainage outlets and anything structural. Cladding and the AXEL louvre system are not available in Canada, so no detail here should be read as a wall or screen assembly. If a detail is not drawn above, take it from Tarimatec's installation manual or from a designer who has seen the site.

Related: the board, joist and clip calculator to quantify the fascia and perimeter, the expansion gap guide for every gap shown above, all planning tools, the installation guide, and the technical specifications.