Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Boral Home Additions & ADU: The Houston Owner’s Guide
A Boral-backed home addition in Houston typically runs $45,000 to $130,000 as a complete project, depending on square footage, foundation work, and how much of the existing structure ties into the new build. Most homeowners discover problems the same way: a cracked corner on the exterior cladding, a door that suddenly won’t latch after two seasons of clay-soil movement, or water staining where the addition meets the original roofline. We’re an independent contractor, not a Boral dealer, which means when we spec Boral materials for your addition or ADU we’re doing it because the product holds up in Houston’s humidity and expansive soils, not because a brand contract tells us to.
Straight scope, straight number – that’s the whole conversation.
Which Boral Models This Applies To
Boral isn’t one product line. In home additions and ADUs, the Boral materials we install most are their exterior trim boards, siding profiles, and the Boral Building Products line that includes TruExterior trim. That’s poly-ash material, which matters in Houston because it doesn’t rot, swell, or wick moisture the way wood and some fiber-cement products do after repeated humid summers and the occasional flooded street corner.
If you’re matching an existing Boral application, look for the product stamp on the back or cut edge of a trim board before you buy replacements. TruExterior trim comes in standard profile dimensions, and the gotcha is this: Boral’s 5/4 trim measures a true 1 inch thick, not the 1-1/8 inch you get from some lumberyard pine. If your addition was built with Boral and you replace a board with standard pine, the reveal line won’t sit right against the siding. We keep this on file from every job we run in Houston. The OEM-versus-aftermarket question is easy for Boral exterior products: there isn’t much aftermarket, because the poly-ash formulation is proprietary. You buy Boral, or you switch materials entirely, and switching materials mid-structure creates a mismatch no amount of caulk fixes permanently.
Styles & brands we work with
Signs Your Boral Home Addition or ADU Is Failing
- Corner trim pulling away from the siding at the outside corners. This is usually not the Boral failing. It’s the framing behind it shifting as Houston’s clay soil expands and contracts through the wet-dry cycle. The trim is just showing you what the studs are doing.
- A door or window in the addition that won’t latch between May and September. Humidity swells the door frame, or the foundation has moved enough to rack the opening. Boral trim boards don’t swell, so if the opening is out of square, the gap shows up at the trim-to-frame line first.
- Staining or paint failure on one wall of the addition but not the others. That’s usually kickback from the roof flashing where the new roofline ties into the original. Water gets behind the cladding and works down to the Boral trim. The trim survives; the fasteners and framing behind it don’t.
- Gaps at the seam where the original house meets the addition. Houston clay moves every structure independently. The addition has its own piers or slab, and if it wasn’t isolated from the original foundation properly, the two buildings move differently. The gap at the seam is the symptom.
- Soft spots in the subfloor near the ADU’s bathroom or kitchen rough-in. This usually traces back to a supply-line fitting that was compressed during the original build and has been weeping inside the wall or under the floor ever since. By the time you feel it, the damage is wider than the leak.
See the difference
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After
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AfterReplacement Cost & What’s Included
In Houston, a full Boral-clad home addition runs $45,000 to $130,000 depending on square footage, foundation type, and the condition of the existing tie-in. An ADU built on a new slab with Boral exterior materials starts around $90,000 and ranges up to $220,000 for larger units with full kitchens and separate utility services. A partial repair – say, replacing failed Boral trim on one wall and remediating the water damage behind it – typically falls between $4,000 and $13,000.
Every number we give you is written before work starts. That’s The Garrison Standard at work: the price is in your hand, in writing, and it doesn’t change unless you change the scope and we put that change in writing too. You’ll see the labor, materials, and permit line items separately on the estimate. No lump sum with a hand-wave. When the job closes, you get the signed 365-Day Done Right Promise, which says that if any of our work fails within a year, we come back and correct it at no charge.
DIY or Call Us?
You can safely walk the perimeter of your addition after a Houston storm and look for obvious gaps, displaced trim, or nail pops. Mark what you see, take photos, and keep them dated. That’s useful information for us when we inspect.
But here’s where DIY goes sideways: if the failure involves a structural tie-in where the addition frame meets the original roofline, or a foundation movement that’s racked a wall out of plane, this is not a caulk-and-paint job. It’s a structural repair that requires lifting or shoring, and doing it wrong weakens both the addition and the original house. Same goes for subfloor rot near plumbing lines – you can’t see the true extent of the water damage until you open the floor. We have the tools, the code knowledge, and the written warranty behind the fix. If you’re seeing signs of failure, call us at (940) 289-7658 and we’ll tell you honestly whether it’s a watch-it or a fix-it-now situation.
FAQs
Boral’s poly-ash exterior products carry a 20-year manufacturer warranty and, installed correctly with proper flashing and fastener schedules, we see them hold paint and hold dimension for 25 to 30 years in Houston’s climate. The weak points are the fasteners and the framing behind them, not the Boral material itself.
Yes, when the failure is localized to trim, flashing, or a single wall section, repair is usually the right call. When the framing behind the Boral is compromised or the foundation has moved enough to rack the structure, a partial repair becomes a full-section replacement. We’ll give you a written scope that tells you which one you have before any work starts.
A single-wall Boral trim replacement with flashing correction typically takes two to three working days. A full addition shell re-clad runs one to two weeks. Structural repairs that involve shoring or foundation isolation depend on the engineer’s report and the permit review time in Houston, which we’ll lay out in the written schedule before work begins.
We maintain working stock of standard Boral TruExterior trim profiles in our Houston shop, so common replacements start without a supplier wait. Custom profiles or full-addition quantities we order directly from our documented Boral supply partners. You’ll see the material lead time on the written estimate before you sign anything.
If your Boral addition or ADU is showing signs of failure, call (940) 289-7658 for a free estimate. Curtis Lane will walk the scope with you, give you a straight number in writing, and tell you exactly what’s wrong and what it takes to fix it – no pressure, no surprises.
Written by Curtis Lane, Owner, Bradford Remodeling Co Houston at Bradford Remodeling Co Houston, serving Houston and nearby areas.
