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Boral Home Additions & ADU: The Los Angeles Owner’s Guide
If you’re reading this, you likely have a Boral product that’s failing, and you need to know what it costs to fix or rebuild. Home additions and ADU construction in Los Angeles typically run $53,100 to $153,400 depending on square footage, foundation work, and whether we’re working with your existing Boral materials or starting fresh. Most homeowners discover a problem when they notice water staining on a Boral siding panel, buckling around a window, or shifting in a Boral paver walkway next to the addition.
We stock Boral-compatible materials for home additions and ADU projects, and we’ll match your existing Boral profile so the new work doesn’t look like an afterthought. Call (949) 850-9896 and we’ll walk through what you’re seeing, whether it’s a repair or a rebuild, and what a written price looks like before any work starts.
Which Boral Models This Applies To
Boral’s home addition and ADU applications fall into three product families. The first is Boral TruExterior siding and trim, which comes in 5/4 and 4/4 thicknesses and multiple profiles: nickel gap, shiplap, board and batten, and the popular 7/16 lap siding. The second is Boral stone veneer, sold through the Cultured Stone line, which includes Southern Ledgestone, Pro-Fit Alpine, and Country Ledgestone profiles. The third is Boral’s paver and hardscape line, often used for patios, walkways, and ADU entry paths.
The compatibility gotcha most homeowners hit: Boral TruExterior siding is no longer in active distribution in many California supply houses, which means matching an existing profile often requires sourcing from regional overstock or transitioning to a James Hardie profile with a deliberate break line. That’s a conversation we have regularly with Los Angeles homeowners. We’ll pull a sample from your existing wall, measure the reveal, check the profile on the back edge, and tell you honestly whether we can match it or whether we need to design a transition that looks intentional.
On the paver side, Boral pavers are concrete, not clay, and the color is through-body, which means a chipped edge shows the same color underneath. If your pavers are flaking at the surface, that’s a sign of a poor original install or a sealer failure, not a Boral material defect. That distinction matters because it changes the repair approach entirely.
For the record: Elmstead Remodeling is an independent contracting company. We are not affiliated with Boral, and we don’t represent ourselves as a Boral distributor. We work with Boral materials because Los Angeles homeowners ask for them by name, and our crews know how they behave in our climate.
Styles & brands we work with
Signs Your Boral Home Additions & ADU Is Failing
- Water staining at siding joints or around window trim. Boral TruExterior is engineered to resist moisture, but if the original installer didn’t flash the butt joints or used the wrong fastener pattern, water gets behind the panel and shows up as staining at the seams. We see this most often on south-facing walls in Los Angeles, where the sun bakes the caulk lines brittle.
- Buckling or wave in the siding plane. This is almost always an install issue. TruExterior needs specific fastener spacing and panel gaps. If the original crew nailed too tight or didn’t leave room for thermal movement, the panels bind and bow. It can happen years after the install, which surprises homeowners.
- Crumbling or flaking stone veneer. Cultured Stone veneer failing at the mortar joints usually points to moisture penetration behind the veneer. In Los Angeles, that’s often a missing weep screed or improper flashing at the roof-to-wall transition. The stone itself rarely fails, which is why we always investigate the water path before quoting a repair.
- Paver settlement or lippage at ADU entry paths. Boral pavers shifting or creating trip hazards typically means a failing base layer, not failing pavers. Los Angeles soil has a lot of clay, and if the original crew skimped on base compaction or drainage, the pavers move with the soil. We’ve lifted pavers on jobs in Silver Lake and Van Nuys and found two inches of sand over uncompacted fill underneath.
- Cracking at the connection point between house and addition. This is the one to take seriously. Differential settling between the original foundation and the addition foundation shows up as cracks at the seam. It’s common in Los Angeles with our freeze-thaw-free but seismically active ground. If you see this, we want to look at it before it gets worse.
See the difference
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AfterReplacement Cost & What’s Included
For a full home addition or ADU in Los Angeles, plan on $53,100 to $153,400. That’s the honest range we quote, and it includes the line-item breakdown before you sign anything. A garage conversion runs lower, $35,400 to $94,400, because the structure already exists. A full ADU with foundation, framing, plumbing, electrical, and finishes runs higher, $106,200 to $259,600, and that range reflects Los Angeles permitting, utility hookups, and the cost of doing the work right.
What drives the variance: square footage, site access (a backyard ADU with no crane access in the hills costs more than a flat lot in the Valley), the condition of your existing electrical panel, and whether we’re matching existing Boral materials or starting with clean lines. Every quote includes a written price before work starts, drop cloths and shoe covers on every visit, and our 365-Day Done Right Promise: if it’s not done right after the job is complete, we make it right.
Named materials are part of the quote, not an upsell. James Hardie exteriors, KraftMaid cabinets, Cambria countertops, Kohler fixtures. You can research every brand by name and verify the warranty yourself before you spend a dollar.
DIY or Call Us?
Here’s the honest split. If you’re dealing with a single cracked paver or a small section of caulk that’s pulling away, you can inspect it safely. Pull the paver, look at the base, snap a photo, and call us to talk through what you found. For siding, trim, stone veneer, or anything where water might be getting behind the surface, call a professional. Boral TruExterior panels are heavy and awkward to handle safely on a ladder, and an improper repair can trap moisture inside the wall cavity where you won’t see it until the framing starts to rot.
Graham Stein grew up in Silver Lake and learned framing and finish work at Los Angeles Trade-Technical College on South Grand Avenue. He’s seen what happens when someone patches Boral siding with the wrong product and calls it done. The written scope is the promise – if it is not on the paper, we have not agreed to it yet. Call (949) 850-9896 and you’ll talk to a live person, not a voicemail box, and we’ll get you a written price before any work starts.
FAQs
Boral TruExterior is engineered for a 25-year-plus lifespan in Los Angeles, provided the original install was done correctly. The panels themselves resist moisture, rot, and UV damage better than most wood products. What fails first is usually the caulk joints and flashing, not the panel, which is why a repair is often more practical than a full replacement. Call (949) 850-9896 and we’ll tell you which one you’re actually looking at.
Yes, in many cases a single damaged panel can be removed and replaced without touching the surrounding siding, assuming we can source a matching profile or create a clean transition. The repair gets more involved when water damage has spread behind multiple panels, because then the sheathing and insulation underneath also need attention. We’ll show you photos of what we find before we recommend a scope.
A single-panel repair is typically one day for removal and one day for installation and finish work, though Los Angeles weather rarely delays us. Full additions and ADU projects run weeks to months depending on permitting, foundation work, and inspections. Your quote includes a project schedule so you know which days the crew will be there and what they’ll be doing, including quiet hours for children’s sleep.
For most Boral profiles we special order from regional suppliers, and we’ll verify availability and lead time before we commit to a schedule. For pavers and Cultured Stone veneer, we can often source within days. We’ll also offer quality equivalents where they genuinely compare: James Hardie for siding, Cambria and Silestone for countertops, KraftMaid for cabinets. You’ll know exactly what’s going on your home, by name, before any work starts.
Written by Graham Stein, Owner, Elmstead Remodeling at Elmstead Remodeling, serving Los Angeles and nearby areas.
