How do I hide the pressure treated framing on a multi-level composite step?

TimberTech fascia is definitely a beast when you're trying to hide every bit of the PT frame, especially on those tight radius curves around a tub. For the vertical wrap, you should skip the standard 12-inch fascia boards and look into using their riser boards or even ripping down deck boards if the budget allows. Ripping deck boards gives you a much thicker profile that you can actually miter and glue with a high-quality PVC cement. If you use the thin fascia, it expands and contracts so much that your miters will open up within one season regardless of how much blocking you use.

To get that seamless look on the curved steps without exposed cuts, you’ve got to lean into heat forming. You can build a simple jig on-site using plywood scraps to match the tub's radius. By heating the boards—either with a specialized heating blanket or a homemade heat box—you can wrap the rim joist perfectly. Once it cools, it holds that shape, and you can fasten it from the backside or use color-matched plugs to keep the fasteners invisible. It’s tedious, but it’s the only way to avoid those ugly faceted angles that scream 'amateur hour' on a high-end build.

For the corners where the multi-level platforms meet, try a **picture-frame border** with a 45-degree miter that’s reinforced with biscuits and PVC glue. I usally double-up the perimeter joists to give myself a massive landing zone for those miters. Since your clients don't care about the cost, spend the extra time on the substructure. If the framing isn't dead-nuts level and square, the composite will telegraph every single imperfection. One trick for hiding the pressure treated wood entirely is to paint the rim joists and any visible blocking black before you install the decking. Even if a gap opens up slightly over time, the black background makes it look like a shadow line rather than a piece of green-tinted lumber peeking through. It’s a small detail that saves you from a callback when the boards inevitably move with the temperature changes.

If you're running Weathered Teak from the PRO Legacy line, you absolutely need the Cortex hidden fastening system. Those color-matched plugs are the only way to satisfy clients who hate exposed screws. For the framing, drop your joist spacing to 10 inch or even 8 inch o.c. around that radius. It gives you more meat for fastening and prevents any 'oil-canning' on the boards.

Instead of paint, wrap your rim joists in G-Tape 304 black flashing tape. It completley blacks out the PT wood and won't flake off like paint when the composite moves. Also, use TimberTech End Coating for any hidden cuts—it keeps the core sealed and invisible.

This sounds like an absolute dream project! I'm just getting started with my first DIY platform and seeing these high-end tips is making me so hyped to try heat forming. Since you guys are talking about hiding the framing on a hot tub build, does anyone know if the heat from the tub itself affects the expansion of the composite boards over time? I'm worried about my gaps widening if the water is always steaming right next to the Weathered Teak!

While the suggestion of painting the rim joists black is a common industry stop-gap, I whould argue that true concealment on a high-spec Weathered Teak build necessitates the application of a high-quality, UV-stable architectural vinyl wrap or a matching PVC trim coil to the structural members before the fascia is even considered. This ensures that even if the inevitable thermal expansion of the TimberTech creates a microscopic gap during the winter months, the substrate remains optically indistinguishable from the finish material, thereby maintaining the illusion of a solid timber monolith that your exacting clients are clearly demanding.