The Problem#
Expanding the 2025 Christmas lights display meant mounting a lot of stuff to brick walls — a 2D pixel matrix on the front of the house, arches running along the front and side fences, and cable runs threading everything together.
The constraint: no drilling. It's our house, but I didn't want to put holes in the brickwork if I could avoid it. Removable, repeatable, and damage-free was the goal.
Commercial brick clips exist — they're used for hanging lights and decorations from brick walls. They work by gripping the edge of a brick and sitting in the recessed mortar joint. Simple enough concept. But off-the-shelf options are designed for hanging lightweight decorations, not for supporting aluminium rods and LED string routing under a Sydney summer sun.
The Design#
The basic principle: print a clip slightly undersized so it grips firmly when flexed over a brick. The clip body presses against the face of the brick, and the toe hooks into the recessed mortar joint behind it.
Getting the dimensions right took a few iterations — bricks aren't perfectly consistent in size, so the clip needs just enough flex to go on without snapping, but enough grip to stay put. I landed on a design that pushes on with a satisfying click and doesn't budge without intentional removal.
I ended up designing three variants for different use cases:
Vertical wall clip — for mounting to vertical brick wall faces. Has a loop or hook on the front for routing LED strings or hanging lightweight rods. Used all the way around the front of the house.
Vertical wall clip with upper extension — a taller variant designed to sit just under window sills where the brick-to-mortar geometry is slightly different. Same grip, more reach.
Horizontal fence clip — for the low brick fences along the front and side. These have holes through the body to accept 6mm fibreglass rods, which become the base of the arch structures. This one needs to be beefier — a fibreglass rod under tension pulls hard — so I cranked the infill up significantly.
Material Choice: ASA#
I printed everything in ASA rather than PLA or PETG. The clips are outdoors through a Sydney summer, in direct sun, for weeks at a time. PLA would've softened and let go. ASA handles the heat and UV without complaint — it's specifically designed for outdoor use, and it's become my go-to for anything that's going outside.
The trade-off is that ASA is a bit trickier to print than PLA. It warps if your bed adhesion isn't good, and it needs an enclosure to stay happy. But once dialled in, the results are solid.
Print settings I landed on:
- Vertical wall clips: 30% infill. You actually want some flex — the clip works because it bends slightly over the brick and springs back. Too much infill and it becomes brittle.
- Horizontal fence clips: 50%+ infill. These need to resist the outward pull of a fibreglass rod and shouldn't flex much at all.
In Practice#
Installing them is satisfying. Press over the brick, feel it click into the mortar joint, done. They held up through the entire season without any falling off — which, given some of the summer storms we had, I was genuinely impressed by.
The only gotcha: some bricks are slightly larger than others, even on the same wall. A batch that fits perfectly on one section might be a tighter push on another. Not a dealbreaker, but worth doing a test clip before committing to a full print run.
Downloads#
The STL files for all three variants are up on Printables. Grab them, tweak the dimensions if your bricks are a different size, and let me know if they work for you.
