Solar Flashing - Tile vs Asphalt vs Metal Roof Decision Matrix

Why this matters

Roof attachment is the single most common source of solar warranty claims, and it is the only part of the install that interacts with the existing roof system. Get it wrong and the customer chases a leak for years that nobody owns - solar contractor blames roofer, roofer blames solar contractor. Each roof type demands a specific flashing strategy that respects how that roof's watertight system works. The matrix below sorts the call by roof type, codifies the right product family for each, and notes where mistakes happen.

Symptom presentation

Three decisions show up in the field:

• New install on a known roof type - pick the product family and document.
• Service call on an existing leak under or near solar - diagnose the flashing failure.
• Retrofit on a roof type the contractor has not done before - confirm the procedure.

Quick checks - 10 minute pass

1. Roof type confirmed by inspection, not contract paperwork. Concrete tile vs clay tile, asphalt 3-tab vs architectural vs class 4 impact-rated, exposed-fastener vs standing seam metal.
2. Roof age and warranty status. Some manufacturers void warranty if non-approved flashing is used.
3. Existing penetrations. How are the existing vents, pipes, and skylights flashed?
4. Slope. Below 3:12 changes the strategy on every roof type.
5. AHJ requirements. Some jurisdictions require manufacturer flashing kits; others accept any UL 441 tested product.

The matrix - by roof type

Asphalt shingle

Standard residential approach: lag bolt through deck into rafter, mounting bracket with deck-flashing slipped under the upper course of shingles.

Approved product families:

• IronRidge FlashFoot 2, QuickMount QBase, EcoFasten Rock-It, S-5 PVKIT (for raised mounts), Unirac SolarMount with proprietary flashings.

Best practices:

• Lag must hit a rafter. Use a stud finder, then confirm by drill bite.
• Pre-drill the deck and rafter to prevent rafter splitting.
• Apply sealant rated for asphalt (NP1 or Geocel 2300) to the lag screw threads and under the bracket base before seating.
• Slip the deck flashing UNDER the upper shingle course at least 6 inches. Never seal flashing to the shingle below it - water needs to drain over the flashing.

Common mistakes:

• Lag missing the rafter, ending in just OSB. Pulls out under wind load.
• Flashing not slid under upper course - relies on caulk that fails in UV.
• Class A fire rating compromised by exposed sealant on flashing edges.

Architectural shingle

Same as 3-tab but the thicker dimensional shingle requires longer flashing legs to clear the shingle butt. Most flashings sold are sized for architectural already.

Class 4 impact-rated shingle (hail country)

Use the same bracket family but verify with manufacturer that flashing is approved for use on impact-rated products. Some manufacturers (Owens Corning, GAF) require specific approved fastening to maintain hail warranty.

Concrete tile

Two approaches:

Tile hook (S hook or J hook) hangs over the batten beneath the tile, allowing the tile to remain in place. Cheaper and faster but disturbs tile alignment, and a misaligned tile leaks.

Tile replacement flashing. Remove the tile under each mount point, install a metal plate flashing that sheds water, place a replacement metal pan that mimics the tile shape, set bracket on top of pan. Better long-term watertight performance, more labor.

Approved products: Quick Mount Tile Hook, Quick Mount Conklin Replacement, IronRidge TilFlash, EcoFasten TileFlash.

Best practices:

• Underlayment is the real watertight membrane. Confirm underlayment is sound (no tears) before placing flashing.
• Tile underlayment installed pre-2000 is often 30-pound felt and is at end of life today. Reroof underlayment before solar if 25-plus years old.
• For S hook installs, brace the hook against the batten so it does not load-transfer through the tile - the tile cracks.

Common mistakes:

• S hook pinches the tile and cracks it in heat cycling. Customer has loose tiles around the array within 3 years.
• Underlayment ignored. Hook installs leak 5-7 years later when underlayment fails.
• Wrong hook profile for the tile's overlap; water bridges sideways.

Clay tile

Same family of products as concrete tile but flashing pans must match clay tile profile (S tile, mission tile, Roman, others). Quick Mount Conklin Universal Adapter is the field favorite.

Clay is more brittle than concrete - extra care during tile removal and reset to avoid cracks. Match replacement tiles by exact manufacturer when individual tiles break.

Standing seam metal

Best case for solar attachment: no roof penetrations needed. Use clamping brackets (S-5! S-5-V, S-5-T, S-5-N depending on seam profile, or Unirac and IronRidge equivalents) that clamp to the standing seam without penetrating the panel.

Best practices:

• Confirm seam profile (S-5! has a profile chart for major panel manufacturers).
• Torque per manufacturer spec. Over-torque crushes the seam; under-torque allows clamp slip.
• For panels with hidden fasteners that hold the seam, verify panel fastening rating against array uplift.

Common mistakes:

• Penetrating standing seam unnecessarily, voiding the panel warranty.
• Wrong clamp model for the seam profile.

Exposed-fastener metal (R-panel, ag-panel, 5V crimp)

Most exposed-fastener panels are penetration-fastened with sealing washers. Solar attachment uses penetration brackets that go through the panel at a high rib, with a butyl pad or EPDM gasket sealing the penetration.

Approved products: S-5 PVKIT 2.0, S-5 ProteaBracket, S-5 CorruBracket, EcoFasten Tile, IronRidge AC-Penetrator.

Best practices:

• Penetrate at the rib (high point) only. Mid-pan penetrations leak.
• Use the manufacturer's gasket - butyl, EPDM, or compressible rubber - matched to the bracket.
• Confirm screw length reaches the purlin or sheathing. Self-tapping screws into thin air do not hold.

Common mistakes:

• Penetration at the pan (low point) where water pools.
• Mismatched gasket compresses unevenly.
• Skipping the bracket's compression test (back-out to check seating).

Flat roof (TPO, EPDM, modified bitumen)

Two approaches:

Ballasted (no penetration): for TPO with sufficient roof load capacity. Concrete or composite ballast trays hold the array down. No penetration, no leak path. Confirm roof structural capacity (10-15 psf ballast load).

Penetrated with adhered flashing patch: solar standoff posts welded to the membrane via field-welded TPO patches by a roofing contractor. Solar contractor sets the posts; roofing contractor flashes them. Document the roofing contractor's role in the warranty chain.

Best practices:

• Membrane manufacturer's specific patch kits.
• Coordinate with roof warranty holder.

Common mistakes:

• Penetration patched by solar contractor without roofing membrane qualification - voids roof warranty.

Confirming the install

Pull-test a sample mount per ASCE 7 uplift requirement (some AHJs require). Water-test the array after install with a hose run at the eave, monitor underside or attic for leaks. Document.

References

• ASCE 7 Minimum Design Loads, Chapter 26-31 wind on solar arrays.
• UL 441 Test Method for Roof-Mounted Solar Modules.
• SEIA Solar Roof Best Practices Guide.
• NRCA Roofing Manual, Steep-Slope Roof Systems, solar attachment chapter.
• Manufacturer instructions for IronRidge, QuickMount, EcoFasten, S-5! product lines.