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Boral Home Additions & ADU: The Pasadena Owner’s Guide
Home additions and ADUs built with Boral materials in Pasadena typically run between $45,000 and $130,000 installed, depending on square footage, foundation work, and how much of the existing structure needs to tie into the new build. When a Boral component fails, it is almost always a moisture-intrusion issue at a seam or flashing point, not the material itself. Homeowners usually notice it as a soft spot near a window, water staining on an interior wall, or a door that suddenly sticks after two winters of perfect operation.
We carry and install Boral-compatible trim, siding, and exterior components for additions and ADUs across Pasadena, from Bungalow Heaven to Hastings Ranch. Our crews have worked on enough Craftsman-era homes in this city to know that Boral’s poly-ash boards behave differently than the original redwood they often replace, and the transition points are where the trouble starts. If you are standing in front of a failed Boral board right now, the short version is this: call (626) 714-2992, describe what you are seeing, and we will put a written price in your hands before any work begins.
Key Takeaways:
- Installed Boral home addition and ADU work in Pasadena: $45,000 – $130,000.
- Most failures are moisture-related at seams, flashing, or ground-contact points.
- Elmstead Remodeling Pasadena is an independent contractor, not affiliated with Boral.
- Written price before work starts, every time, on every project.
Which Boral Models This Applies To
Boral’s exterior product lines show up on Pasadena additions and ADUs in a few specific ways. The two most common are Boral TruExterior trim boards (which carry a 20-year warranty against rot and termites) and Boral Versetta Stone siding panels, which install as a screwed-on, mortarless stone veneer. If you are trying to identify what you have, look at the cut edge: TruExterior is a dense, gray, poly-ash composite that cuts clean without the fibrous tearing you see in wood; Versetta Stone panels have a visible mounting flange at the top edge and interlock on the sides.
The compatibility gotcha we see regularly in Pasadena is this: Boral TruExterior comes in specific thicknesses, most commonly 4/4 (actually 3/4-inch dressed) and 5/4 (1-inch dressed), and you cannot swap one for the other without adjusting every reveal, drip edge, and window casing on that elevation. A homeowner with a 4/4 board will sometimes get sold a 5/4 replacement because it was in stock, and then the siding plane no longer meets the window trim the way it did. We match the dressed thickness, not just the nominal dimension.
On the OEM-versus-aftermarket question for Boral specifically: because TruExterior is a proprietary poly-ash blend, there is no true third-party equivalent board that carries the same weather-resistance profile. Aftermarket PVC trim (Azek, Veranda) can be milled to similar dimensions, but it expands and contracts at a different rate in Pasadena’s hot summers, and the joints will telegraph through paint faster. For Boral Versetta Stone, we treat the panels as the OEM category and only use aftermarket corner pieces and trim accessories where the profile gauge matches exactly.
Styles & brands we work with
Signs Your Boral Home Additions & ADU Is Failing
- Paint blistering or peeling at a Boral trim joint. Poly-ash boards do not rot, but trapped moisture behind them will push through the paint film. The board is usually fine; the flashing behind it failed first.
- A Versetta Stone panel that has loosened or shifted. This is almost always a screw that missed the mounting flange during installation, often on the second course from the top where ladder angle makes alignment harder.
- Dark staining running down from a window or door head. The head flashing was either omitted or cut too short to direct water past the Boral trim face. Pasadena’s winter rain pattern makes this show up fast.
- Soft or buckling stucco adjacent to Boral trim. The bond between stucco and poly-ash trim will fail if the gap was not properly backer-rodded and caulked. You will feel a hollow thump when you knock on it.
- Ants or termites in Boral trim. Boral does not rot or feed termites, but if the board is in ground contact, moisture wicks up and creates a path for insects to reach the wood framing behind it. The Boral looks fine; the framing behind it is not.
See the difference
Before
After
Before
After
Before
AfterReplacement Cost & What’s Included
For Boral-specific repair work on an existing Pasadena addition or ADU, smaller-scope fixes like replacing a section of failed trim run on the lower end, while full Boral exterior reclads with new Versetta Stone or TruExterior siding and trim can reach the mid five figures depending on elevation complexity and scaffold requirements. The full addition or ADU build with Boral materials falls in the $45,000 – $130,000 range, with ADUs built from the foundation up landing higher.
| Scope of Work | Typical Pasadena Installed Range |
|---|---|
| Boral trim repair or targeted replacement | $800 – $3,500 |
| Boral Versetta Stone section repair | $1,200 – $4,500 |
| Full Boral exterior re-clad (trim and siding) | $15,000 – $40,000 |
| Home addition with Boral exterior materials | $45,000 – $130,000 |
| ADU with Boral exterior materials | $90,000 – $220,000 |
Every Boral repair or install includes drop cloths on the floors, shoe covers on every crew member, and a photo of the cleanup before we leave. The written price we hand you before work starts includes the Boral material cost, the labor, the fasteners rated for Boral’s specific expansion coefficient, and the flashing details. The price you see on paper is the price you pay at the end, no footnotes. Workmanship is covered under the 365-Day Done Right Promise: if it is not done right, we make it right.
DIY or Call Us?
What an owner can safely do: identify whether the Boral board is actually failed or just cosmetically weathered. If the board feels solid when pressed, the paint is peeling but the material underneath is clean and dry, and there is no staining on the interior side of the wall, you have a paint-prep issue, not a Boral failure. You can also check ground clearance: Boral trim should sit at least 6 inches above grade in Pasadena’s clay-heavy soils, and if it does not, that is a moisture-path problem worth flagging to us before it becomes a framing problem.
Where DIY goes wrong: cutting out a Boral board without understanding the flashing sequence behind it. Boral does not fail on its own; it fails because water got behind it. Remove the board without correcting the flashing detail, and you will repeat the repair in two years, except now the framing has taken on more moisture. If any part of the diagnosis involves electrical, gas, or structural connections on your addition or ADU, stop and call a trained professional. For Boral exterior work, call (626) 714-2992 and we will schedule a walkthrough. The estimate is free, and the written price comes before a single drop cloth goes down.
FAQs
Boral TruExterior carries a 20-year rot and termite warranty, but in Pasadena’s high-UV summers and wet winters, we tell homeowners to expect the paint cycle to run 7 to 10 years before repainting, while the board itself should outlast the house. Call (626) 714-2992 for an exact assessment of what your addition or ADU needs.
Yes, in many cases we can remediate the flashing detail and reset the existing board if the material is still sound, which saves the cost of new Boral stock and repainting the entire elevation. Call (626) 714-2992 and we will tell you honestly whether repair or replacement makes more sense for your specific Pasadena house.
A targeted trim repair typically takes one day, while a full Boral exterior re-clad on an addition or ADU runs one to two weeks depending on scaffold access and weather windows in Pasadena. Call (626) 714-2992 for a timeline based on your specific scope.
We keep common Boral TruExterior profiles (1×4, 1×6, 5/4 corner boards) and a selection of Versetta Stone panels in our Pasadena inventory, and we order specialty profiles and colors per job, typically arriving within a week. Call (626) 714-2992 and we will check stock while you are on the phone.
Since 2005, Elmstead Remodeling Pasadena has handled additions, ADUs, and exterior repairs across Pasadena, and we also work with KraftMaid, Cambria, and Silestone on interior projects. Graham Stein and the crew have worked steadily through Bungalow Heaven, where the older Craftsman bones require careful demo and a slower hand than most crews are willing to give. If your Boral addition or ADU has a problem, call (626) 714-2992. A live person answers, we will put the written price in front of you, and the drop cloths go down before the first board comes off.
Written by Graham Stein, Owner, Elmstead Remodeling Pasadena at Elmstead Remodeling Pasadena, serving Pasadena and nearby areas.
