Boral Home Additions & ADU Nationwide

Boral Home Additions & ADU: The Los Angeles Owner’s Guide

If you’re planning a home addition or ADU in Los Angeles with Boral materials already on site (or specified in your plans), we can keep the project moving. Depending on square footage, site conditions, and finish level, a Boral-compatible home addition in Los Angeles typically runs $53,100 – $153,400, while a full ADU with Boral stone or brick veneer lands between $106,200 and $259,600. Most owners discover a problem when the Boral cladding, trim, or moisture barrier shows signs of failure mid-project or years after the original build: cracks, water staining, or separation at the corners where the addition ties into the existing house.

Call (936) 259-2607

Here’s the situation we see most often in Los Angeles: the original addition was built with Boral stone or brick veneer over an improperly flashed transition, and years of seasonal rain and sun have worked water behind the veneer. The homeowner spots a hairline crack running through the Boral, or paint blistering on an interior wall nearby. That’s the moment to call. Not because the house is falling down today, but because a water path into the framing gets more expensive every month it’s open.

We’re an independent remodeling contractor serving Los Angeles, not a Boral dealer or factory representative. That matters because we recommend what actually fits the existing structure, not what one manufacturer happens to sell. We work with Boral products regularly on additions and ADUs across the city, and we stock the fasteners, flashing, and compatible trim profiles those materials require.

Which Boral Models This Applies To

Boral manufactures stone and brick veneer systems, trim boards, and siding profiles that show up in a lot of Los Angeles additions and ADUs, especially Craftsman-style and Spanish-style projects. The compatibility question usually comes down to which Boral product line was used: StoneCraft, Cultured Stone (now part of Westlake Royal), or the Versetta Stone panel system. Each uses different clips, rainscreen details, and joint treatments.

Here’s the gotcha we see repeatedly in Los Angeles: Boral’s Versetta Stone is a panelized, mortarless system that installs from the top down, not the bottom up. If you’re adding onto an existing Versetta Stone wall, you can’t just start laying new panels at the bottom of the addition. The panels lock into a starter strip, which means the tie-in point has to be planned from the top course of the addition downward. We’ve had to correct this on more than one project where a previous contractor started the addition wall without accounting for panel direction.

OEM versus aftermarket matters here more than with most building materials. Boral’s manufactured stone veneer is color-blended in ways that are difficult to match with generic stone from a supply yard. If you need to extend an existing Boral stone wall, we recommend sourcing from the same product line and ideally the same batch where possible. For trim and flashing, quality aftermarket equivalents from brands like Tamlyn or Boral-compatible PVC trim work fine, and we keep those on the truck.

Signs Your Boral Home Additions & ADU Is Failing

• Hairline cracks running through the veneer corners. This usually means the addition’s foundation settled differently than the original slab, or the substrate behind the Boral wasn’t given proper movement joints. In Los Angeles, clay soil expands and contracts dramatically between wet winters and dry summers, which puts real stress on veneer corners.
• Water staining or efflorescence (that white mineral crust) on the Boral surface. This tells us moisture is moving through the stone or brick, not shedding off it. The culprit is almost always missing or improperly lapped flashing at the roofline, window heads, or the seam where the addition meets the original wall.
• Boral trim boards pulling away at the seams or corners. Boral’s composite trim expands less than wood, but it still expands. If the installer butted the boards tight instead of leaving the manufacturer’s required gap, you’ll see buckling or gapping at mitered corners within a year or two.
• Interior drywall cracking or paint blistering on the wall shared with the addition. Water that gets behind Boral veneer eventually finds the framing. By the time you see it inside, the flashing has been failing for a while.
• Loose or rattling veneer pieces when you tap them. This can mean the mortar bond failed or the mechanical fasteners weren’t installed to spec. Either way, that section needs to come off and be reinstalled before pieces start falling.

Replacement Cost & What’s Included

For a Boral-related repair on an existing Los Angeles addition or ADU, you’re usually looking at $2,360 to $7,670 for a localized veneer or trim repair with flashing correction. A larger re-cladding job or a tie-in repair where the addition meets the original house can run $8,260 to $21,240 depending on access, scaffolding, and how much demolition is required to get to the failed flashing. Full home additions with Boral veneer specified from the start run $53,100 – $153,400, and full ADU construction runs $106,200 – $259,600.

What drives the number: how much of the existing Boral has to come off to find the real problem, whether we’re working at height (a two-story addition tie-in needs scaffolding, which is a real cost), and whether the original substrate (the moisture-resistant layer behind your veneer) was installed correctly or has to be rebuilt. We give you a written price before any work starts. That number includes labor, materials, debris hauling, and the flashing and weather barrier materials. If we find something worse behind the wall, you’ll know before we touch it, and the change is in writing too.

Every Boral repair or addition gets our 365-Day Done Right Promise: if the work fails inside the guarantee period, we come back and fix it at no charge. Covered in writing, on every project.

DIY or Call Us?

You can safely check a few things yourself. Look for visible gaps at the roofline where flashing should be visible. Tap suspicious veneer pieces with a wooden dowel and listen for a hollow rattle. Inspect caulk joints at windows and corners. Those are all visual checks that don’t require tools or a ladder past one story.

What you shouldn’t do is remove Boral veneer yourself to “take a look.” Behind that veneer is the weather barrier, and behind that is your wall framing. If you cut into the WRB (weather-resistant barrier) and don’t re-lap it correctly, you’ve created a new water path that was never there before. We’ve also seen homeowners try to patch Boral with a mismatched stone from a big-box store, which leaves a visible patch that never blends and usually leaks at the seam. High work on a two-story addition needs scaffolding, harnesses, and someone who knows how to tie it off. That’s not a weekend project.

If you’re seeing cracks, staining, or loose veneer, call us at (936) 259-2607. Trevor will ask you for a few photos first. As Trevor says, “Give me the whole picture first, then we pick up the tools.”

FAQs

Call for a Written Quote

If your Boral addition or ADU is showing cracks, staining, or loose veneer, don’t wait until the water reaches your framing. Call us at (936) 259-2607 and we’ll schedule a free estimate. You’ll get a written price before any work starts, a real arrival window, and a written guarantee on the repair. A live person answers the phone, any hour.

Written by Trevor Nash, Owner, Penhallow Remodeling at Penhallow Remodeling, serving Los Angeles and nearby areas.