Eagle Rock, CA · June – July 2022 · LADWP / LADBS

Eagle Rock: the tile hooks went back because this roof was shingle.

Rails travel between houses. The parts that fix into the roof are chosen for the roof they fix into.

Written by the Cali Energy project team · California contractor license 1032379 · Updated September 2026

Mounting hardware is selected for the roof covering, not for whatever is left in the van. A tile roof takes a hook that reaches under the tile and fixes to the structure beneath it. A composition shingle roof takes a mount that lands on the deck, sits inside the shingle course and is flashed over. They solve the same problem in incompatible ways, and neither substitutes for the other. On this Eagle Rock roof the covering was shingle, so the tile hooks left over from a previous house went back to the supplier for credit and Cali Energy ordered the footings and attachments this roof actually called for.

At a glance

Roof

Composition shingle

Ordered for this roof

Footings and attachments

Returned

Tile hooks left from a previous house

Carried over

The rails

Final inspection

Requested in July

Utility / AHJ

LADWP / LADBS

The story

A week before the crew was due, the hardware list arrived: footings and attachments for this roof, ordered against this job. With it came a second instruction that is more interesting than it looks — the tile hooks bought for the previous house were to go back to the supplier, with the invoice, so the credit would actually land.

To somebody outside the trade that reads like inventory housekeeping. It is a roofing decision, and it is the one that decides whether a roof leaks in five years.

The two coverings are attached in fundamentally different ways.

On tile, the fixing has to get past the tile without relying on it. A tile hook reaches under the course, fixes into the rafter or the deck, and comes back out between the tiles with enough lift that the tile above still seats flat. The tile carries nothing; it is lifted, worked under, and put back.

On composition shingle, there is nothing to reach under. The mount lands directly on the deck, inside the shingle course, and the weatherproofing is a flashing slipped up under the course above so that water running down the roof passes over the top of it. The shingle is not lifted out of the way — it is built around.

So a tile hook on a shingle roof is not a compromise, it is the wrong object. There is nothing for it to hook under, its geometry lifts the rail away from a surface that does not need clearing, and the detail it was designed to weatherproof does not exist here. Anybody who has tried to make one work has produced a penetration sealed with mastic and hope, which is the classic source of a leak found three winters later, under an array, and blamed on the array.

The rails are a different matter entirely. Rail is extruded aluminum in standard lengths and it does not care what is underneath it. Carrying rail from one job to the next is ordinary and sensible. It is the parts that touch the roof that have to be bought for the roof.

Which is why the return came with an instruction about the invoice. Hardware bought against one job and left on a shelf is not a spare — it is money, and without the paperwork it is a write-off. Returning it properly is the difference between specifying the right parts for a roof and being quietly punished for doing so.

The attachments arrived ahead of the modules, the array went up at the end of June, and the final was requested in the first week of July — then moved by a few days, which is ordinary: an inspection request is a date, and dates move for both sides.

Cali Energy designed, permitted and installed this array in Eagle Rock, Los Angeles.

How it ran

Two weeks from a hardware list to an array, and one box of parts sent back rather than forced onto the wrong roof.

What we did

• Specified footings and attachments against this roof rather than against the warehouse.
• Returned the tile hooks from the previous house with the invoice so the credit landed.
• Had the attachments on site before the modules rather than with them.
• Booked the final in the first week after the array was complete.

System specifications

Is your project like this one?

• Your quote does not say which attachment it uses on your roof.
• You have been told the mounting hardware is the same on every roof.
• You have tile on one part of the house and shingle on another.
• You are comparing two quotes and only one lists the mounting parts.

Cali Energy in Eagle Rock

Frequently asked questions

Is solar mounting hardware the same on tile and shingle roofs?

No, and they are not interchangeable. A tile roof takes a hook that reaches under the course and fixes to the structure, lifting the rail clear so the tile seats back flat. A shingle roof takes a mount fixed to the deck inside the course, weatherproofed by a flashing rather than by clearance.

What keeps a shingle roof mount from leaking?

The flashing, not the sealant. A metal flashing is slipped up under the course above the penetration so that water running down the roof passes over the top of it. Sealant alone at a penetration is the classic cause of a leak found several winters later.

What happens if a tile hook is used on a shingle roof?

It has nothing to hook under and its geometry lifts the rail away from a surface that did not need clearing, so the detail it was designed to weatherproof is absent. What is left is a penetration relying on mastic, under an array, where nobody will look at it again.

Can unused mounting hardware be returned?

Yes, with the invoice — which is the part people forget. Parts bought against one job and left on a shelf are not spares, they are money, and without the paperwork the credit does not happen and buying the right hardware for the next roof starts to look expensive.

Does Cali Energy install solar in Eagle Rock, Los Angeles?

Yes. Eagle Rock has mixed roofs — tile on one street and composition shingle on the next — permitted through LADBS and interconnected through LADWP. The attachment is specified per house, and the rails are the only part that travels between them.

What this would look like on your roof

Related

• Forty modules on a tile roof in three levels Hollywood Hills, Los Angeles · 16 kW · wired for a battery not yet bought Solar
• The module changed before anything went up Eagle Rock, Los Angeles · what has to be rechecked when the panel changes Solar
• Seven of thirteen panels went on tilt frames El Sereno, Los Angeles · 5.3 kW · one roof, two mounting decisions Solar
• The roofer came twice, and the second time mattered Granada Hills, CA · 19 modules · roofing and solar interleaved, not queued Solar
• A module broke on the day of the install Atwater Village, Los Angeles · 7.02 kW · why the gap cannot be left Solar

This timeline reflects this property and this permitting path. Updated September 2026.