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Boral Home Additions & ADU: The West Covina Owner’s Guide
Boral home additions and ADU projects in West Covina typically run $45,000 to $130,000 for a permitted addition, and $90,000 to $220,000 for a full accessory dwelling unit. These are complete-project figures, not just the Boral material components, because in Southern California you’re paying for foundation work, seismic anchoring, and Title 24 energy compliance alongside the build itself. Most owners discover their “Boral part” problem isn’t a single failed component at all: it’s a mismatch between an older addition’s roofline and the new Boral profile, a deteriorated connection point where the addition meets the original house, or an underbuilt foundation that West Covina’s expansive clay soil has shifted over two decades. We sort all of it.

Key Takeaways:
- Boral additions in West Covina range $45,000 – $130,000; detached ADUs run $90,000 – $220,000
- The most common failure point is the addition-to-house connection, not the Boral materials themselves
- West Covina’s clay soil and 100°F summer swings create expansion stress that older additions weren’t engineered for
- Mason Remodeling Co West Covina delivers a written price before any work starts, every time
Which Boral Models This Applies To
Boral manufactures concrete and stone veneer, roofing tiles, and trim profiles used across West Covina additions built from the late 1990s through today. The part you’re trying to match depends on which system was used: Boral’s Cultured Stone veneer comes in specific panel dimensions (typically 8″ and 16″ heights with varying lengths), while Boral concrete roof tiles are profile-specific, meaning a “flat” tile won’t interlock with a “barrel” tile from the same house. Here’s the gotcha most people hit: Boral color lots vary by production run, so a replacement panel purchased today won’t perfectly match stone or tile installed eight years ago. That’s why we order Boral materials in the largest available matching lot and blend new pieces across the existing wall or roof plane rather than patching in one corner. For West Covina homeowners adding a room or converting a garage to an ADU, we recommend OEM Boral materials where the existing structure stays visible, and quality aftermarket equivalents only where full re-covering is planned and uniform color matters more than matching. Mason Remodeling Co West Covina is an independent contractor, not affiliated with Boral, but we work with their full product line and know which distributors in the San Gabriel Valley keep what in stock.
Styles & brands we work with







Signs Your Boral Home Additions & ADU Is Failing
- Cracking at the addition seam: Where your original house meets the add-on, a vertical or stair-step crack means the two foundations are moving independently. West Covina’s clay soil expands when wet and shrinks when dry, pulling structures apart at their weakest joint.
- Boral stone veneer spalling or popping off: Water got behind the veneer, froze or heated, and broke the mortar bond. You’ll see pieces on the ground after a hot Santa Ana wind cycle. This is a moisture-management failure, not a product defect.
- Roof tile slippage at the transition: The pitch change where a Boral tile roof meets a shingle addition is the classic leak point. If you see cracked or shifted tiles within three feet of that transition, the flashing underneath is failing.
- Doors sticking or drywall cracks inside the addition: Foundation settlement is expressing itself through your walls. West Covina homes built before 2000 rarely had post-tension slabs, and an older addition on a conventional footing will move.
- Dry rot at the bottom plate of the addition’s framing: Termite and water damage at the sill plate means the original addition wasn’t flashed or drained correctly. You’ll smell mustiness before you see the damage, especially in west-facing walls that catch afternoon sun and dry slowly.
See the difference
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After
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AfterReplacement Cost & What’s Included
For a full home addition in West Covina, you’re looking at $45,000 – $130,000 depending on square footage, foundation scope, and whether you’re tying into the existing roof or building new. Garage conversions run $30,000 – $80,000 because the shell exists. A ground-up detached ADU is $90,000 – $220,000 once you factor in site work, utility trenching, and West Covina’s permit and school-district fees. Every Mason Remodeling Co West Covina project includes a written line-item price before we start, so you see exactly what the Boral materials cost, what labor costs, and what the city requires. We pull permits, coordinate inspections, and stand behind the work with our 365-Day Done Right Promise: if anything isn’t right within a year of completion, we fix it at no charge.
DIY or Call Us?
For a Boral addition or ADU, this isn’t a DIY conversation, it’s a structural one. Foundation work, roof framing, and seismic anchoring are not weekend projects, and West Covina’s building department will not sign off on unpermitted structural work. What you can do safely: photograph the crack patterns, mark them with a pencil and date, and watch whether they grow over a two-week period. That tells us whether you’ve got active movement or settled movement before we ever set foot on the property. If your issue is a small veneer patch or a few displaced roof tiles, call us anyway; we’ll tell you honestly whether it’s a handyman job or a contractor job. You should know what you’re getting before we ever pick up a tool. Call (707) 760-7579 and we’ll walk you through what we’re seeing from your photos, free.
FAQs

A properly permitted and built Boral-clad addition should last the life of the original house, which in West Covina means 60 to 80 years, assuming the foundation was engineered for the local clay soil and the roofline transition was flashed correctly. The Boral products themselves carry manufacturer warranties, but the real lifespan limiter is always the connection detail and drainage. Call (707) 760-7579 if you’re seeing movement; early intervention is always cheaper.
Yes, in most cases we can repair a failing addition, especially when the issue is isolated to one connection point, a section of veneer, or a roof transition. If the foundation itself has shifted beyond tolerance, repair becomes foundation work first, which is still usually far less than a rebuild. An exact answer requires an inspection; estimates are free.
An ADU conversion typically takes 4 to 7 months from permit submittal to final inspection; a ground-up addition runs 6 to 10 months, with West Covina’s plan-check and inspection scheduling being the biggest variable. Isaac Pruett keeps schedules honest and scopes tight, so if something will cost more or take longer, you’ll hear it before the work starts.
We don’t warehouse Boral products, but we order from San Gabriel Valley distributors who stock the full line, and we coordinate delivery to match our build schedule exactly. For matching existing Boral stone or tile, we bring physical samples to your West Covina home and color-match on-site. Call (707) 760-7579 to schedule your free estimate; a written price comes before any work begins.
Written by Isaac Pruett, Owner, Mason Remodeling Co West Covina at Mason Remodeling Co West Covina, serving West Covina and nearby areas.


