SunMesa installs residential and small-commercial rooftop solar across the high desert. Their crews were spending too much time on the roof aligning and fastening rail splices — the small plates that join mounting-rail sections into a continuous run — and in the labor math of solar, roof time is the whole game.
The joint that slowed the crew
A typical SunMesa array uses long rows of extruded rail, spliced together every couple of meters. The generic splice plate they were buying worked, but it needed a free hand to hold alignment while a second hand started the fasteners — awkward on a pitched roof, and slower than it should be across dozens of splices per job.
On a fixed-price install, every extra minute per splice comes straight out of margin. SunMesa wanted the joint to fall together.
Designing for the person on the roof
We reworked the splice plate around the installer's hands, not the drawing. Formed alignment tabs index the plate into the rail channel so it self-locates and holds position, letting one person seat both fasteners. Slotted holes absorb the thermal expansion an aluminum array sees between a desert night and a summer afternoon.
Because SunMesa's roofs bake in UV and see blowing grit, corrosion resistance and a durable surface mattered as much as the geometry.
The part we built
The plate is stamped from 2.0mm 5052-H32 aluminum — marine-grade corrosion resistance, the right strength for a structural splice — and clear-anodized for a hard, weather-stable surface. Hole and tab positions are held to ±0.15mm so every plate drops onto the rail the same way, and there's no galvanic mismatch with the aluminum rail.
We run it in the tens to hundreds of thousands per year range, so SunMesa gets consistent parts and pricing that scales with their install volume.
Minutes per splice, multiplied
The self-aligning tabs turned a two-hand job into a one-hand job. SunMesa's crews reported the splice went together noticeably faster, and across a full array of splices that added up to real time back on every roof.
Multiply a couple of minutes saved per splice across dozens of splices per job and hundreds of jobs a year, and a smarter little plate pays for its tooling many times over.
“Solar is a roof-time business. Proco redesigned the splice around how the crew actually works, and we got minutes back on every single job.”
Renée Colton, Install Manager, SunMesa Solar