While that method works fine for basic setups, there is a much better way to do it: laying aluminum joists across those pedestals first, then resting the pavers on top of the joist frame.
If you’re planning a patio project, here is a practical look at why the joist method is almost always worth the extra step.
How the Two Methods Compare
To understand why joists make such a difference, it helps to look at how each system supports your patio.
- Direct-on-Pedestal: You place adjustable plastic pedestals on the ground or roof deck, arranged in a grid pattern. The four corners of each porcelain paver rest directly on top of a single pedestal head.
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- Aluminum Joist System: You still use pedestals, but fewer of them. Instead of holding up tiles directly, the pedestals support a framework of lightweight aluminum joists. The porcelain pavers then rest on top of this sturdy continuous rail system.
Why the Joist Method Built-To-Last
Setting pavers directly on corner pedestals leaves a lot of room for minor shifts over time. Adding aluminum joists fixes the main pain points of raised tile installations.
1. Real Structural Stability
Porcelain pavers are incredibly tough, but they are relatively thin compared to traditional concrete pavers. When supported only at four corners, large-format tiles can flex slightly under heavy weight or impact. If a corner pedestal settles even a fraction of an inch into the ground, the tiles above it become uneven, creating "lippage"—those annoying edges you trip over.
An aluminum grid distributes weight evenly across the entire surface. The joists act as a single rigid deck frame, eliminating sag and keeping every tile flush with its neighbor.
2. Complete Design Flexibility
When using corner pedestals, your paver layout is restricted. You have to install tiles in a simple grid (stack bond pattern) so every corner meets nicely over a pedestal head.
With joists, you have a continuous support surface underneath. You can install pavers in staggered running bond patterns, herringbone designs, or mix different tile sizes without needing to calculate complex pedestal placements underneath every seam.
3. Faster, Easier Leveling
Leveling direct-on-pedestal systems can be a tedious chore. Every single pedestal must be adjusted independently to make sure the four corners of four adjacent tiles sit at the exact same height.
With a joist system, you only level the main frame. Once your aluminum tracks are flat and square, setting the tiles on top goes remarkably fast, and you don't have to worry about individual corners dipping or riding high.
4. Superior Moisture and Drainage Management
Proper airflow and drainage are critical under any raised deck to prevent mold, rot, or standing water. Aluminum doesn't absorb water, rust, or warp like
wood framing. Placing pavers on joists elevates the entire surface cleanly, creating an open air channel underneath that allows rainwater to run off efficiently while letting the subfloor breathe.
See also: Clever Level 80-200 mm pedestal, 3 mm for tiles & decking
A Connected Framework That Helps Limit Movement
Another important difference is how the supporting elements work together. When pavers rest directly on individual pedestals, adjacent pavers may share a pedestal head, but there is no continuous framework connecting the supports. Without suitable perimeter restraint and positioning components, pavers can shift sideways, joints can open, and edges can move out of alignment.
Aluminum joists provide a common, continuous support for multiple pavers. When the joists and their connections are assembled into a properly secured framework, they tie the supporting structure together and help maintain the relative positions of the pavers and supports. This creates a more coherent terrace assembly and reduces the potential for independent movement.
The principle is similar to a ring beam tying the walls of a building together: connecting separate supporting elements helps the overall assembly remain stable. In a terrace system, however, the joists connect the substructure; simply resting pavers on them does not mechanically fasten the pavers together. The full benefit depends on the specified joist connections, paver positioning components, and perimeter restraints, while allowing for drainage and thermal movement.
What This Means in the Real World
Whether you are building the space yourself or hiring a contractor, the installation method directly impacts how the patio feels and holds up over time.
- For Homeowners: Walking across a joist-supported patio feels solid and permanent—much like a traditional stone slab ground patio—rather than hollow or springy underfoot. You won't have to deal with shifting corners or stubbed toes over the years.
- For Contractors: Labor time shifts from meticulous micro-adjustments at every tile corner to straightforward frame assembly. You spend less time troubleshooting uneven pavers and leave behind a job site that won't result in callbacks for sagging tiles.
While setting porcelain pavers directly on pedestals can save a bit on material costs up front, building on an aluminum joist frame provides a flatter, stronger, and far more durable outdoor space.
