Boral Flashing Replacement Nationwide

Boral Flashing Replacement: The San Diego Owner’s Guide

Boral flashing replacement in San Diego typically costs $285 – $640 installed, depending on how much flashing is failing and whether the underlying decking needs repair. We stock Boral-compatible flashing parts on our trucks and can usually complete the swap in a single visit once we’ve matched the correct profile to your roof. Most homeowners discover the problem the hard way: a brown stain on the ceiling after the first real rain in November, or a call from a neighbor pointing at a lifted corner of flashing near the chimney. Boral tile roofs are known for their longevity, but the flashing around penetrations, valleys, and sidewalls wears out long before the tile itself does. In San Diego’s coastal air, that wear happens faster than most people expect.

Call (619) 810-5520

We’re Mercer Roofing Co San Diego, and we’ve been replacing failed flashing on Boral roofs across this city for the better part of two decades. Grant Whitlock, our owner, walks every flashing job himself before a single nail goes in. That’s not a sales pitch; it’s just how we work.

Which Boral Models This Applies To

Boral manufactures several tile profiles, and each one has slightly different flashing requirements at the edges and penetrations. The most common profiles we see in San Diego are the flat shake, the barrel mission, and the slate-look profiles. The flashing itself is generally standard galvanized steel, copper, or lead in 26-gauge through 30-gauge, but the way it’s cut, bent, and stepped depends on the tile profile and the roof pitch. The compatibility gotcha many homeowners run into: sidewall flashing for a Boral flat profile won’t seat correctly on a barrel profile, because the step height and the way the tile overlaps the flashing leg are different. If someone installs the wrong profile flashing, the tile sits proud of the wall, water finds the gap, and you’re back to square one in a season.

If you can still see the original Boral installation paperwork, look for the profile name. If not, we can identify it from a photo or a quick visit. We install OEM Boral flashing when it’s available and the roofing system is still under warranty, and we also use high-grade aftermarket flashing that matches or exceeds the original gauge and coating. For most San Diego homes, a 26-gauge galvanized or a pre-painted steel flashing will last 15 – 25 years, and copper flashing, which we use less often these days, can go 40 or more if installed correctly. We stock standard step flashing, pipe boot flashing, and valley flashing on our trucks, which means the common repairs don’t wait on a parts order.

One note for full transparency: Mercer Roofing Co San Diego is an independent roofing contractor. We are not affiliated with Boral, and we don’t claim to be. We just install and repair Boral roofs often enough to know the flashing profiles inside and out.

Signs Your Boral Flashing Replacement Is Failing

• Water stains on ceilings or walls after rain. This is the most common first signal. Flashing that’s pulled away from a chimney or sidewall lets water travel behind the tile and follow the underlayment until it finds a seam, a nail hole, or a decking joint, and from there it drips into the living space. By the time the stain shows, the flashing has usually been compromised for a season or more.
• Lifted, curled, or missing flashing at a roof-to-wall junction. In San Diego, the marine layer and the occasional Santa Ana wind work on flashing like sandpaper. Step flashing especially can lift when the nails holding each step corrode or the caulk seal fails. If you can see daylight between the flashing and the wall, water is already getting through.
• Granular rust or white corrosion on the metal. Galvanized flashing has a zinc coating that eventually sacrifices itself. Once that coating goes, the base steel starts rusting. In coastal neighborhoods like Point Loma or La Jolla, we see flashing rust through five to ten years faster than inland, simply because of the salt in the air.
• Debris dams or moss packing behind the flashing leg. Boral tile roofs shed most debris, but in the valleys and behind chimney flashing, leaves and grit build up at the transition points. That trapped debris holds moisture against the flashing and accelerates corrosion. The flashing itself may still be intact, but the seal is compromised by the constant damp.
• Crumbling or cracked sealant around pipe boots and vents. The rubber boot around plumbing vents and the caulk at flashing edges degrade in San Diego’s UV-heavy sunlight. When the caulk fails, the metal can still look fine from the ground, but the water is getting between the flashing and the tile. This is the one we most often find during a roof tune-up, before the leak has even made it to the ceiling.

Replacement Cost & What’s Included

For a standard Boral flashing replacement in San Diego, you’re looking at these installed price ranges:

• Single pipe boot flashing replacement: $285 – $395
• Step flashing along one sidewall (up to 20 linear feet): $420 – $640
• Chimney flashing repair (one side, including new counter-flashing): $350 – $550
• Valley flashing replacement per valley: $500 – $800

That’s the installed price, including the part, the labor, the trip, and the cleanup. What drives the range is the tile profile, the condition of the underlayment where we’re working, and whether we can reuse the existing tile or need to set replacement tile around the flashing. A barrel mission roof takes longer to flash correctly than a flat profile, so labor runs higher on those. Before any work starts, we give you a written price. If we open things up and find rotted decking beneath the flashing, we’ll show you what we found, explain what it means, and give you a written change order before proceeding. No surprises on the invoice, ever.

Every Boral flashing replacement we install includes our 365-Day Done Right Promise. If the flashing fails within a year, we come back and make it right at no charge. That’s a written guarantee on every repair, and it’s included automatically.

DIY or Call Us?

Flashing replacement is not a ladder-and-caulk job, and we say that plainly because we’ve seen what happens when it’s done wrong. The work often requires lifting tile, cutting metal to profile, and working at height, near roof edges, and around penetrations. The risk of a fall is real, and we don’t want anyone learning that lesson the hard way. What a homeowner can safely do is identify the problem from the ground: note where the stains are, take photos of visible flashing, and check for lifted metal after a wind event. That’s useful information for the estimate call. The actual replacement, especially on a two-story San Diego home, belongs with someone who is trained, insured, and carrying proper fall protection.

When we send a technician to your home, you’ll know who’s coming before they arrive. The technician’s name and photo are sent to you ahead of the visit, and they’ll badge in with a photo ID at the door, in a clean, marked uniform. That’s the Threshold Verified standard we hold every visit to. If you’d rather talk it through first, call (619) 810-5520 and we’ll walk through what you’re seeing over the phone.

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