For a homeowner concerned about roof leaks, what installation methods and mounting systems should they prioritize when comparing installers?

To completely minimize the risk of roof leaks, you must prioritize installers based on their specific mounting hardware, flashing techniques, and waterproofing protocols tailored to your exact roof type.

Prioritize the following specialized installation methods and mounting systems when vetting companies.

1. Match Mounting Systems to Your Roof Type

How the system attaches dictates your leak risk. Look for installers utilizing these specific non-penetrating or ultra-flashed systems:

• Standing Seam Metal Roofs: Prioritize non-penetrating seam clamps (such as S-5! Clamps ). These grip the roof's standing seams mechanically, avoiding any drilled holes or risk of water entry.
• Flat Roofs: Prioritize ballasted mounting systems or advanced, zero-penetration adhesive-based mounts (like Solar Stack Go to product viewer dialog for this item.). These utilize heavy blocks or specialized adhesives to secure the array safely using gravity and friction, keeping your underlying roof membrane entirely puncture-free.
• Asphalt Shingle Roofs: Look for installers using integrated elevated water seal flashing (such as IronRidge FlashFoot Go to product viewer dialog for this item. or QuickMount PV Go to product viewer dialog for this item.). These systems combine a structural lag bolt with a wide metal flashing plate that slides securely up and under the existing shingles, forcing water to flow seamlessly around the attachment point rather than pooling against it.
• Tile Roofs: Prioritize installers using specialized tile hooks or tile replacement mounts . They must never drill through tiles; instead, they should lift the tile, fasten a heavy-duty hook directly to the underlayment and rafters, and sub-flash the area to completely shield the underlying wood.

2. Strict Installation & Waterproofing Methods

When interviewing installers, demand that they outline their specific field execution protocols. Reject any contractor who cannot explicitly guarantee these steps:

• Triple-Layer Sealant Protocol: Installers must inject a heavy bead of high-grade, roof-compatible sealant directly into the pilot hole, apply it generously underneath the flashing foot, and seal around the collar of the lag bolt.
• No Exposed Sealant: Avoid any installer who uses structural sealant or caulking as their primary defense against water. Sealants contract, degrade under harsh UV rays, and eventually fail; mechanical metal flashing must always be the main water barrier.
• Rafter-Only Anchoring: Ensure the crew utilizes digital rafter locators or snakes a camera in the attic to verify lag bolts hit structural rafters dead-center. Missing a rafter creates a "shiner" (an empty hole through your roof deck), which acts as a direct conduit for water leaks into your attic.

3. Critical Warranty and Credentials to Demand

An installer's hardware is only as reliable as the warranty backing it up.

• 10-to-25-Year Workmanship Warranty: Insist on a comprehensive roof-penetration warranty that covers leaks directly caused by the solar hardware or labor.
• Roofing + Solar Dual-Certification: Prioritize companies that carry active licenses for both roofing and solar electrical work . Standard solar companies often void your existing roof manufacturer's structural warranty when they drill; a dual-licensed contractor can seamlessly preserve or wrap that original roof coverage.

To help tailor this advice further, what ** roofing material** does your home currently have, and how old is the roof?

If you’re comparing solar installers and your biggest concern is roof leaks, I’d prioritize the roof attachment and waterproofing details over small differences in panel brands or system price.

What to prioritize

• Flashed roof attachments, not sealant-only penetrations. On shingle roofs, look for mounting feet/standoffs that are properly flashed and integrated with the roofing layers. NREL specifically recommends flashing or flashed standoffs at roof penetrations, along with appropriate sealing.
• Attachments into structural members. Lag screws/bolts should penetrate into rafters or other appropriate structural framing—not merely the roof decking. The installer should be able to explain the attachment pattern and structural/wind-load calculations.
• A real flashing system rather than relying on caulk. Butyl tape or high-quality roofing sealants can be part of the system, but you don't want "we put sealant around every bolt" to be the primary waterproofing strategy.
• Minimal penetrations where practical. If your roof type permits a non-penetrating mounting method, it can reduce the number of potential leak points. For example, standing-seam metal roofs can use clamp systems that attach to the seams without penetrating the roof.
• Roof-specific mounting hardware. The mounting system should be designed for your particular roofing material—composition shingles, standing-seam metal, tile, low-slope membrane, etc.—rather than the installer using essentially the same attachment approach on every roof.
• Installer/roofer coordination. If the roof is being replaced or is relatively old, consider having the roof work and solar mounting coordinated. DOE recommends assessing roof condition before installation, and NREL notes that installing penetrating mounts during roof construction can make proper flashing and warranty coordination easier.
• Explicit roof-leak responsibility. Get in writing who pays for diagnosis, roof repair, panel removal/reinstallation, and consequential damage if a leak develops. DOE specifically recommends asking the installer who is responsible if installation damages the roof or a leak develops.
• Roof warranty compatibility. Ask whether the roofing manufacturer and installer approve the proposed mounting method and whether the solar installation affects your existing roof warranty. NREL notes that PV installations can increase leak/damage risk through additional attachments and rooftop traffic, making warranty coordination important.

Mounting systems I'd favor

1. Roof-specific flashed rail/rack systems — generally my first choice for shingle roofs. A properly engineered rail system with flashed attachments gives you a robust mechanical connection while allowing the waterproofing to be integrated into the roof assembly.

2. Seam clamps — excellent for standing-seam metal roofs. These can avoid roof penetrations altogether, which is a major advantage for a leak-conscious homeowner.

3. Ballasted systems — worth considering on appropriate low-slope/flat roofs. They avoid roof penetrations, but they aren't automatically "better": added weight, wind loading, roof-membrane protection, and eventual roof maintenance/removal all need to be addressed.

4. Ground-mounted solar — potentially best if minimizing roof risk is the overriding concern. If you have suitable property, moving the array off the house eliminates solar attachment penetrations from the roof altogether.

Red flags when interviewing installers

I'd be wary if an installer says:

• "We just seal the bolts with caulk."
• They can't show you where the attachment penetrates the rafter/truss.
• They won't specify the mounting hardware and flashing method in the contract.
• They don't inspect the roof before quoting.
• They won't explain what happens if the roof leaks.
• They have no clear process for coordinating with your roofing contractor/manufacturer.
• They propose putting solar on a roof that's near the end of its useful life without discussing replacement first.

A good installer should be able to give you a roof-attachment diagram, identify the exact mounting hardware, explain the flashing/waterproofing sequence, and state the structural and warranty assumptions in writing. DOE also recommends comparing multiple qualified installers rather than choosing solely on price.

Bottom line: For a leak-sensitive homeowner, I'd rank proper flashing + structural attachment + roof-specific hardware + warranty responsibility above almost everything else. The cheapest quote can become the most expensive if a dozen poorly waterproofed penetrations turn into a roof problem.

When you're vetting roofing installers and want to bulletproof your home against leaks, the installation methods and mounting systems matter just as much as the shingle or panel quality. Here is a breakdown of what to prioritize and discuss with contractors:

• Flashing and Metal Integration: Prioritize installers who use step flashing (individual overlapping pieces of metal) for roof-to-wall intersections rather than cheap continuous L-flashing that can warp. For chimneys and skylights, look for custom-fabricated copper or aluminum crickets and step flashing sealed with high-grade secondary membranes, not just a bead of caulk.
• Underlayment Strategy: Move past standard black felt paper. Prioritize contractors who install a full-coverage self-adhered ice and water barrier ( peel-and-stick membrane) across vulnerable areas—valleys, eaves, rakes, and penetrations—or ideally across the entire roof deck for ultimate waterproofing.
• Valley Construction: Avoid "open woven" valleys where shingles cross each other tightly and trap debris. Prioritize a closed-cut valley or, better yet, a metal valley system (W-valley) made of corrosion-resistant flashing that cleanly channels water off the roof.
• Penetration Mounting Systems: If you have or plan to install solar panels, prioritize installers (or solar partners) who use non-penetrating or flashed mounting attachments (like QuickBOLT or EcoFasten) that integrate directly into the flashing system. They should never rely on raw sealant or silicone squeezed through a drilled hole as the primary waterproof barrier.
• Fastening Technique: Ensure the contractor enforces strict hand-nailing or precisely calibrated pneumatic nailing . Over-driven nails cut into the shingle mat (causing blow-offs and leaks), while under-driven nails prevent proper sealing.

If you'd like, tell me:

• What type of roof material you have (asphalt shingle, tile, metal, etc.)
• If you are planning a solar installation soon

I can tailor these questions specifically for your contractor interviews.

If you’re comparing solar installers, and roof leaks are a major concern, I’d put waterproofing and attachment details ahead of panel brand or price.

What to prioritize

• Flashed roof penetrations, not sealant-only attachments. For a conventional shingle roof, look for mounting feet/standoffs with purpose-designed flashing that is integrated into the roofing layers. DOE guidance specifically warns that sealant alone can deteriorate from UV, weather, and movement; flashing provides the more durable water-management layer.

• Attachments that hit the actual roof structure. Ask whether lag screws/bolts will be located into rafters or other designed structural members—not merely the roof decking. The installer should be able to show how the attachment pattern was designed for wind and other loads.

• A mounting system with a documented flashing solution. Don't just ask, “Do you use flashing?” Ask for the specific racking/mount and flashing product, its installation instructions, and how it is compatible with your particular roof covering. UL now has a dedicated standard/outline for PV flashing devices and systems designed to resist water penetration.

• Roof-specific installation methods. The best method depends on the roof:

• Asphalt shingles: flashed attachment points integrated beneath the appropriate shingle courses are preferable to simply caulking a bracket on top.

• Standing-seam metal: prioritize seam clamps that avoid penetrating the roof where the roof/mounting system permits it.

• Low-slope/membrane roofs: ask specifically about membrane-compatible attachments, flashing, drainage, and protection layers. Ballasted systems can avoid penetrations but must be engineered for wind and use appropriate protection so the racking doesn't damage the membrane.

• Tile roofs: ask exactly how tiles are handled and replaced around attachments rather than accepting a generic “we seal everything” answer.

• Coordination with the roofer/manufacturer. If the roof is relatively new, ask the installer to confirm in writing that its mounting and flashing method won't compromise the roof manufacturer's warranty. DOE guidance recommends coordination between the roofer and solar installer around flashing and installation procedures.

Questions I'd ask every installer

1. “Show me the exact mounting foot and flashing system you'll use on my roof.”
2. “How does each attachment connect to the rafters/trusses?”
3. “Is the waterproofing dependent on sealant, or is there mechanical flashing?”
4. “Who installs and warranties the flashing—the solar company or a roofer?”
5. “What happens if my roof leaks at one of your attachment points five years from now?”
6. “Will you document the attachment/flashing locations before the panels cover them?”
7. “Does this installation affect my existing roof warranty, and can you provide that in writing?”
8. “If my roof needs replacement later, what do you charge to remove and reinstall the array?”

A particularly good sign is an installer who is comfortable showing you the waterproofing detail before installation, rather than merely promising that its work “won't leak.”

One more important consideration: if the roof is already near the end of its useful life, replace/repair the roof before installing a long-lived solar array. Otherwise you may eventually pay to remove and reinstall the panels just to reroof.

Bottom line: I'd favor properly flashed structural attachments, roof-specific mounting hardware, and a clearly assigned roof-leak warranty over an installer offering a cheaper installation with generic brackets and lots of caulk.

If you're comparing solar installers and your biggest concern is roof leaks, I’d prioritize the installer’s roof-attachment and waterproofing method over the brand of panels or even the racking brand.

What to prioritize

1. Proper flashing—not sealant alone

   • For a typical asphalt-shingle roof, favor mounts with a purpose-designed flashing system that integrates with the shingles and underlayment.
   • Be wary of an installer whose explanation boils down to “we put sealant around the bolts.” DOE guidance specifically notes that sealants can deteriorate from UV, weather, and movement; flashing provides a more durable water-management layer.
   • Ask to see a cross-section/photo of the actual mount and flashing detail they intend to use.

2. Attachments into the roof structure

   • On sloped roofs, mounts should be engineered and fastened into rafters/trusses or other approved structural members, rather than merely relying on the roof sheathing.
   • Ask how they locate rafters and how they verify that every attachment hits the intended structural member.

3. A mounting system matched to your roof

   • Asphalt shingles: flashed attachment feet/bolts are the conventional approach.
   • Standing-seam metal: prioritize non-penetrating seam clamps when compatible with the specific roof profile and manufacturer requirements. This avoids creating holes in the metal roof.
   • Tile/slate: look for purpose-designed hooks/attachments and an installer experienced with that roof type; improper tile removal and flashing can create additional leak risks.
   • Low-slope/flat membrane: investigate ballasted or appropriately engineered membrane-compatible systems where feasible, since eliminating penetrations can be advantageous—but the added weight and wind uplift still need engineering.

4. Roofing and solar expertise together

   • Particularly if the roof is older, ask whether the installer will coordinate with a qualified roofing contractor. DOE guidance recommends coordinating flashing and mounting work with roofers, and notes that roofing contractors are best suited to perform permanent roofing/flashing work.

5. An inspection before the panels cover everything

   • This is a very good differentiator between installers. Ask whether they will photograph/inspect the attachment points, flashing, sealant and conduit penetrations before rails and panels conceal them.
   • The installation should have an intentional sequence for waterproofing and inspection rather than treating leak prevention as a final caulking step.

Questions I'd ask every installer

“Exactly how will you waterproof every roof penetration?”
“Are the attachments going into rafters/trusses, and how will you verify that?”
“What flashing system and mounting-foot product are you proposing?”
“Is that mounting system approved for my specific roofing material and covered by the roof manufacturer's requirements?”
“Can I see photos of the attachment and flashing work before the panels go on?”
“If my roof leaks after installation, who is responsible for diagnosing and repairing it?”

One especially important point: don't automatically choose the system with the fewest holes. A properly engineered penetrating mount with excellent flashing can be preferable to a supposedly “non-penetrating” system that isn't appropriate for your roof or isn't adequately engineered for wind loads. The goal is the fewest well-designed penetrations, properly integrated into the roof's water-management system.

If the roof is already near the end of its useful life, I'd seriously consider reroofing before installing solar; otherwise you may eventually have to remove the panels to replace the roof.

When you're vetting roofing or solar installers to protect against leaks, the mounting approach and penetration method are the absolute first line of defense. Prioritize these standards during your comparisons:

• Flashing Integration Look for step flashing (for standard roofs) or continuous metal flashing that integrates directly with your shingle or tile layers rather than relying solely on sealant. Water should be shed over the flashing planes via gravity, never depending on caulk as a permanent waterproofing barrier.
• Stand-Off Mounts For solar or heavy roof attachments, prioritize elevated stand-off mounts that keep hardware well above the plane of the roof. This ensures water, snow, and ice can flow freely around the penetration rather than pooling against it.
• Non-Penetrating or Standing Seam Clamps If you have a metal standing seam roof, prioritize installers who use compression clamps that grip the seams directly. This eliminates roof penetrations entirely, meaning zero holes are drilled into your deck.
• Secondary Water Barriers / Flashing Caps Premium installers use specialized waterproof underlayment patches, rubber boots (like QuickFlash Go to product viewer dialog for this item. or SolarSpeedboot Go to product viewer dialog for this item.), or self-adhering ice-and-water shield cones around every single lag screw or anchor bolt.
• Quality Sealants and Fasteners Ensure they use high-grade, UV-resistant polyurethane or MS polymer sealants (avoiding cheap silicone that degrades in the sun) and stainless steel or coated fasteners that won't rust and degrade the surrounding membrane over time.

Would you like me to detail how to ask contractors about their warranty coverage for leaks , or are you comparing quotes for a specific type of roof material (shingle, tile, or metal)?

If you’re comparing solar installers, and your biggest concern is roof leaks, I’d prioritize the installer’s waterproofing method and roof/warranty coordination over the brand of panels.

What to prioritize

1. Flashed roof attachments—not just sealant

   • On asphalt-shingle roofs, look for mounting hardware with an integrated flashing flange that is installed beneath/into the roofing layers so water sheds around the penetration.
   • Be wary of an installer whose explanation boils down to “we put sealant around the bolts.” NRCA guidance specifically says caulks and sealants should not be relied upon as the primary defense against water infiltration.
   • The DOE's Building America guidance likewise treats solar mounting penetrations as potential weak points and says proper flashing should be part of the installation.

2. Attachments tied into the roof structure

   • Ask whether lag screws/bolts are going into rafters or other structural framing, rather than merely the roof sheathing.
   • The installer should be able to show you the attachment detail and explain how wind and snow loads are transferred into the structure.

3. A mounting system specifically approved for your roof type

   • Standing-seam metal: Prefer clamps that attach to the standing seam without drilling holes, when the roof and manufacturer allow it. This eliminates a major category of penetration-related leak risk.
   • Asphalt shingles: Use purpose-designed flashed mounts with the flashing integrated into the shingle courses.
   • Tile: Look for properly flashed tile hooks/replacements rather than improvised drilling through tiles.
   • Flat membrane roofs: Don't automatically assume “non-penetrating” is best. Ballasted systems avoid penetrations but can obstruct drainage and make roof inspection/maintenance harder; some membrane manufacturers instead favor mechanically attached systems with approved, warranted flashing.

4. Roofing manufacturer compatibility and warranty This is a big one. Ask the installer in writing:

   • Does the mounting system comply with my roofing manufacturer's requirements?
   • Will installing solar affect my existing roof warranty?
   • Who is responsible if a mount leaks—the solar company, roofer, or mounting-system manufacturer?
   • Is the flashing covered by a watertight warranty?

   Some roof manufacturers require their approved attachment systems and/or an authorized roofing contractor for the flashing.

5. An installer who is comfortable involving a roofer For a relatively new roof, I'd favor a solar company willing to coordinate with the original roofing contractor or a qualified roofer. A roofing contractor can verify the roof's condition and perform the flashing work, while the solar installer handles the PV system. NRCA specifically recommends qualified roofing contractors and licensed electricians be involved with PV-ready roof installations.

6. A roof inspection before installation Don't let an installer put a 25-year solar array on a roof that may need replacement in a few years. The installer should document the roof's age, condition, existing flashing, and expected remaining service life.

What I'd ask every installer

“Show me exactly how each roof penetration will be waterproofed. What flashing product and mounting system will you use, where does it attach structurally, and whose warranty covers a leak caused by the attachment?”

Then ask for the manufacturer's installation detail, not just a verbal explanation.

Red flags 🚩

• “We just seal the bolts with roofing sealant.”
• They can't identify the exact mounting hardware before you sign.
• They don't inspect the roof first.
• They won't coordinate with your roofing contractor.
• They say solar automatically preserves your roof warranty without checking the warranty requirements.
• They can't tell you who pays for roof repairs if a mounting point leaks.
• They propose covering a flat roof extensively with ballast without discussing drainage and future roof access.

Bottom line: For a typical pitched shingle roof, I'd favor a properly flashed, structurally attached mounting system installed according to the roofing manufacturer's requirements, with the flashing covered by a clear warranty. Avoid choosing an installer simply because they promise “no leaks”; make them explain—and document—the actual waterproofing detail.

When interviewing and comparing solar or roofing installers, a homeowner concerned about leaks should prioritize specific installation methods and waterproof mounting systems that maintain the roof's structural integrity.

Flashing and Waterproofing Systems

• Flashing integration: Prioritize installers who use stamped aluminum or stainless steel flashing (like Oatey or QuickBOLT systems) that integrate directly under the shingle courses, rather than relying solely on surface sealants.
• Flashing placement: Ensure they use a three-tier flashing method (flashing goes under the top shingle, over the middle shingle, and rests above the lower shingle) to shed water away from the penetration point naturally.
• Waterproof underlayment: Look for systems that incorporate a self-adhering polymer modified bitumen waterproof membrane (ice and water shield) patched or layered around the penetration area.

Mounting and Attachment Methods

• Compression/Standoff mounts: Prioritize raised standoff mounts over direct-fastener setups; these lift attachments above the plane of the roof to keep water from pooling around the bolt.
• Lag bolt sealing: Ensure installers use pre-drilled lag bolts injected with structural-grade polyurethane or silicone sealant (such as Bostik Go to product viewer dialog for this item. or *Sikaflex Go to product viewer dialog for this item. * ) before driving the bolt into the rafter, combined with a rubber or EPDM sealing washer compressed at the base.
• Non-penetrating alternatives (when applicable): For flat or low-slope roofs, prioritize ballasted or fully adhered mounting systems that eliminate roof penetrations entirely.

Installer Verification Checklist

• Rafter targeting: Contractors must locate and anchor directly into the roof rafters/trusses , not just the OSB/plywood roof decking, to prevent shifting and subsequent seal failure.
• Code compliance & engineering: Verify that the contractor pulls local permits and adheres to ASCE 7 structural standards for wind-uplift resistance, which prevents the mounting hardware from rocking loose during storms.
• Workmanship warranty: Prioritize companies offering a minimum 10-year workmanship warranty specifically covering roof penetration leaks (separate from the manufacturer hardware warranty).

If you'd like, let me know:

• What type of roof material you have (asphalt shingle, tile, metal, or flat)
• Whether you are planning a solar installation or a standard roof attachment

I can give you more targeted questions to ask your installer.

When evaluating roofing contractors to prevent and minimize the risk of roof leaks, you should prioritize installation methods and mounting systems that emphasize multi-layered flashing, penetration sealing, and structural integrity.

Here are the key installation methods and mounting systems to prioritize:

• Flashing and Counter-Flashing Integration : Prioritize installers who use continuous, step, and valley flashing made of durable, corrosion-resistant metals (like aluminum or copper) rather than relying solely on sealants. Flashing should be properly integrated under the primary roofing material and up vertical walls or chimneys with secure counter-flashing.
• High-Performance Underlayment Systems : Look for installers who use high-temperature self-adhering polymer modified bitumen (ice and water shield) across the entire roof deck or at vulnerable areas (valleys, eaves, and penetrations) rather than standard, cheap felt paper. This provides a waterproof secondary barrier if shingles fail.
• No-Curb and Flashed Solar Mounts (If Applicable) : If you have or plan to install solar panels, prioritize mounting systems that use specialized waterproof flashing attachments (like Quick-Mount PV or similar lagged flashing systems) rather than standard L-feet bolted directly through shingles with just sealant. The mount itself must be flashed into the shingle layers like a shingle or tile.
• Properly Flashed Roof Penetrations : Ensure contractors use specialized rubber boot flashings (such as Oatey or retro-fit lead/silicone boots) for plumbing vents, exhaust fans, and chimneys, secured with storm collars and high-grade exterior caulking or sealants rated for thermal expansion and contraction.
• Drip Edge and Starter Strip Integration : Prioritize installers who install a metal drip edge over the underlayment at the rakes and eaves (or underlayment over the drip edge at the eaves depending on local code and ice dam risk) coupled with a dedicated starter strip shingle. This prevents wind-driven rain from wicking up under the first row of shingles or rotting the roof decking edge.
• Nail Placement and Fastening Precision : A leak-resistant roof depends heavily on correct fastening. Prioritize installers who adhere strictly to manufacturer specifications regarding the exact placement, angle, and depth of roofing nails (avoiding high-nailing or under-driven/over-driven nails that compromise the shingle seal or tear through the mat).

If you'd like, let me know:

• What type of roof material you currently have (asphalt shingle, tile, metal, flat)?
• Are you planning to add solar panels or other roof attachments?

I can give you more targeted questions to ask your prospective installers.

If you’re comparing solar installers for a roof where leaks are a major concern, I’d prioritize the roof-attachment and waterproofing details over the brand of panels or inverter.

1. Prioritize flashed roof attachments

For a conventional asphalt-shingle roof, look for mounting feet/attachments with integrated metal flashing that goes underneath the shingles, rather than a system that relies primarily on caulk or sealant.

The best practice is for the attachment to:

• Fasten into a rafter/truss or other structural member, not merely the roof decking.
• Use a purpose-designed flashing assembly.
• Shed water over the attachment rather than asking sealant to keep water out.
• Follow both the mounting manufacturer's instructions and the roofing manufacturer's requirements. NABCEP specifically calls for roof penetrations to be flashed and weather-sealed.

This matters because sealant alone can deteriorate from UV, temperature cycling and movement; Building America specifically recommends flashing as an additional layer of weatherproofing.

2. For standing-seam metal roofs, strongly favor non-penetrating clamps

If you have a standing-seam metal roof, ask installers about seam-clamp mounting that attaches to the raised seams without drilling through the roof panels.

That's an especially attractive option from a leak-prevention standpoint because you avoid creating roof penetrations altogether. NABCEP notes that standing-seam clamps are a standard example of non-penetrating attachments, subject to approval by the roofing manufacturer.

3. Be cautious about “we just seal the lag screws”

I'd be wary of an installer whose explanation is essentially:

“We drill through the roof and put sealant around the screws.”

A proper installation can certainly involve roof penetrations, but sealant should not be the only line of defense. Ask specifically what flashing system is used and ask to see a diagram or photograph of the actual attachment detail. Building America notes that older practices relying solely on sealants have proven problematic over time.

4. Ask about the exact mounting product—not just the rack manufacturer

“ We use IronRidge” or “We use Unirac” isn't enough. Ask:

• What exact roof attachment are you using?
• Is it flashed or non-penetrating?
• Where does the flashing sit relative to the shingles?
• What seals the fastener penetration?
• What structural member does each attachment connect to?
• How are penetrations for conduit handled?
• Who installs and warranties the flashing—the solar company or a roofing contractor?

The attachment itself is only half the equation; installation quality and correct flashing are critical.

5. If your roof is old, address that before solar

A new solar array can remain on the house for decades, so putting it on a roof that's nearing the end of its life can create an expensive problem: eventually you may have to remove the panels to reroof.

I'd favor an installer who actually evaluates the roof first and is willing to recommend reroofing rather than simply selling you solar. ENERGY STAR likewise recommends reviewing the roof warranty and ensuring the contract addresses damage or leaks caused by installation.

6. Compare warranties very carefully

For a leak-conscious homeowner, I'd want the proposal to spell out:

“If your installation causes a roof leak, who pays for the diagnosis, roof repair, and removal/reinstallation of the panels?”

That's much more useful than a generic 25-year equipment warranty. Also check whether the solar installation affects the existing roof warranty.

My preference by roof type

One particularly useful question to ask every installer is: “Show me exactly how you waterproof one of your roof attachments, and tell me what happens if it leaks five years after installation.” The quality of that answer can tell you considerably more than the sales pitch.

If you're in the Bay Area, I'd also pay particular attention to installers who routinely work with your specific roof type and can coordinate solar with a licensed roofer when necessary.