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Boral Home Additions & ADU: The Los Angeles Owner’s Guide
A full Boral home addition or ADU in Los Angeles typically runs $53,100 to $153,400 installed, and we stock the framing, siding, and trim materials to match most current Boral product lines. Most owners call us after a failed inspection or when an existing addition has settled and the Boral siding or trim has cracked at the corners, letting water behind the envelope. Penhallow Remodeling Los Angeles is an independent remodeling contractor, not affiliated with Boral, but we work with their materials every month across this city.
Which Boral Models This Applies To

Boral manufactures several product lines relevant to Los Angeles additions and ADU construction, and the compatibility details matter more than most suppliers admit. The two we see most often are Boral TruExterior siding and trim and BoralVersetta stone veneer. TruExterior comes in lap, panel, and board-and-batten profiles, and it is engineered from a fly-ash polymer that behaves differently than wood or fiber cement. The manufacturer’s published data rates it for a 50-year warranty, which holds up better in LA’s dry heat than in humid markets, but the polymer does expand more than fiber cement, so spacing at butt joints has to be tighter. If you are matching existing Boral siding on a 1990s-era addition, we need the profile name and a measurement of the exposure, because TruExterior lap comes in 4, 5, 6, 7, and 8-inch exposures and those are not interchangeable once the siding is up.
On BoralVersetta stone, the panels come in two thicknesses and a range of color blends. The big compatibility gotcha in Los Angeles is color matching: Boral changed several Versetta blend formulas around 2018, so a panel purchased today in a given color name may not match the same-named panel from a 2015 wall. We handle this by ordering extra panels from the newest production run and doing a controlled blend across the wall. For genuine Boral brand materials we always recommend OEM panels over the aftermarket lookalikes, because the fire rating and the warranty depend on the real thing, and Los Angeles hillside fire zones do not leave room for shortcuts.
Styles & brands we work with







Signs Your Boral Home Additions & ADU Is Failing
- Cracked TruExterior corner boards at the foundation line. Polymer trim that was installed tight to grade wicks moisture through capillary action, then expands and contracts through LA’s 40-degree day-to-night temperature swings until the corners crack. That crack is the first place water gets behind the wall.
- Siding panels pulling loose near windows or doors. Fastener schedule matters with Boral. Nails driven too close to panel edges, less than three-quarter inch from the cut edge, will blow out within a few seasons, especially on the south-facing walls that bake in the afternoon sun.
- Visible gaps at TruExterior butt joints in late summer. Every Los Angeles house with Boral siding moves a little through the dry season. Gaps that open beyond an eighth of an inch by August mean the installer did not follow the gapping chart, and now every one of those joints is a water entry point.
- Versetta stone panels bowing off the wall. BoralVersetta panels get clipped and screwed per panel, but if the substrate behind them is OSB that has swelled from a past roof leak, the screws lose bite and the panel bows. You can push on the panel and feel it flex. That is not a cosmetic issue.
- Drywall cracks or musty smell inside the ADU after rain. The Boral product did not fail first in most of these cases. The flashing at the roofline or window heads did. But the symptom shows up behind the siding, and by the time you smell it, the sheathing is already wet. This is the first thing we check on older Los Angeles additions.
See the difference
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AfterReplacement Cost & What’s Included

For a full home addition build or ADU build using Boral materials in Los Angeles, the installed range is $53,100 to $153,400. A remodel that involves removing and replacing failed Boral siding on an existing addition typically comes in lower, and the main cost drivers are the square footage of wall area, the profile type, whether the sheathing behind the siding has to come off, and whether the job is one story or two. Two-story work adds scaffold or lift time, and on tight Los Angeles lots that access often raises the number.
Every number we give includes the materials, labor, disposal, and our written 365-Day Done Right Promise. If the siding cracks again or the stone veneer bows inside a year, we come back and fix it at no charge. No service call fee, no re-inspection charge. Trevor Nash has been standing by that promise for years, and he gives you the number before anyone picks up a tool. We also write the price down, not just say it aloud, so the number on day one is the number on the invoice.
DIY or Call Us?
There are safe things to check on your own. Look at the butt joints, check for cracked corners, and push gently on any Versetta panels. Snap a photo of the profile and measure the exposure. Beyond that, removing Boral siding or stone veneer is not a weekend job. TruExterior panels are heavier than wood, the fastener pattern has to be exact, and getting water management right around windows and at the base of the wall is what separates a 20-year install from a 2-year one. If this is on a second story, call us. Scaffolding and a polymer siding panel do not mix well with a homeowner ladder.
Call (213) 277-6578 and we will send a background-checked, uniformed technician to look at what you have, identify the profile, and write you a firm number for the repair or the build.
FAQs

Boral warranties TruExterior for 50 years, and in Los Angeles’ dry climate the polymer material itself will generally outlast the paint. The weak points are installation details like butt joint spacing, fastener placement, and flashing, which is why the labor side matters as much as the product. Call us at (213) 277-6578 and we will look at the install quality, not just the material.
Yes, in most cases we can cut out and replace individual damaged Boral TruExterior panels or Versetta stone sections. The catch is color matching on older BoralVersetta blends, which is why we order from the newest run and blend across the wall. For an exact quote on a partial repair, call (213) 277-6578.
A partial siding repair on a one-story wall usually takes one to two days on site. A full ADU build using Boral materials takes months, and we give you a written schedule with defined arrival windows before work starts. We do not quote same-day starts on planned construction, but a live person will answer when you call to get the timeline started.
We stock common TruExterior lap profiles, trims, and a small range of Versetta stone blends at our Los Angeles yard. Some colors and less common profiles are ordered from Boral’s western distribution network, which usually adds a few days. We also regularly install KraftMaid and Cambria materials on the interior side of our ADU and addition projects, and stock Silestone for countertop phases. Call (213) 277-6578 and we will check stock on your exact profile while you are on the phone.
Written by Trevor Nash, Owner, Penhallow Remodeling Los Angeles at Penhallow Remodeling Los Angeles, serving Los Angeles and nearby areas.


