The sample board looks excellent at forty-five degrees. The framing beneath it now has a different job.
This is worth resolving before the boards arrive. Changing direction on delivery day can turn a finish choice into a framing revision.
Read the product row, then the pattern note
The 2026 Trex guide, page 22, lists support spacing by product and load rating. For its 1x6 products at the listed 100 psf rating, the table shows 16 inches on centre. Its angle note reduces the listed spacing by 4 inches for boards installed at 45 degrees.
That is a specific manufacturer example, not a universal composite rule or an Ontario design load. Other profiles and brands need their own instructions. Confirm the guide applies to the product being supplied and the loads in the deck design.
A small sketch prevents a large misunderstanding
Draw three parallel joists. A board crossing them squarely takes the shortest route between supports. Turn the board diagonally and that unsupported length grows, even though nobody moved a joist.
Now draw the border. Boards running along the edge may need additional framing beneath them. The pretty line around the perimeter should have a support detail, not a promise that someone will improvise one.
Spacing is only half the conversation
Oakville's deck drawings ask for joist size, span, and spacing. These are separate inputs. Closely spaced joists still need adequate capacity between beams; a strong joist can still leave the surface boards too widely supported.
Ask for both checks in the framing plan. Include butt joints, breaker boards, stair openings, and the chosen fasteners rather than treating them as finishing details.
Compare quotes on the same drawing
- Exact board collection and profile, not simply "composite."
- Board direction and the relevant manufacturer spacing requirement.
- Additional supports at borders and board ends.
- Any framing repairs or levelling needed before resurfacing.
If two quotes assume different board directions, their totals are not yet comparable. Settle the drawing first. The colour debate can keep going over coffee.