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CertainTeed Home Additions & ADU: The Long Beach Owner’s Guide
Home additions and ADUs framed, sheathed, and insulated with CertainTeed products in Long Beach typically run $45,000 to $130,000 installed, depending on square footage, foundation work, and whether you’re adding a room or a full detached unit. We stock CertainTeed-compatible framing, insulation, and exterior materials on our trucks, and we can usually start a site assessment within a few days of your call. Most Long Beach homeowners discover they need this level of work when a room no longer fits the family, or when a rental unit becomes the difference between affording the mortgage and not.
CertainTeed is one of the most respected names in building materials, and their Gypsum Board, drywall, and Sustainable Insulation lines show up in additions and ADUs across Long Beach from Belmont Shore to Bixby Knolls. If you’re looking at this page, you probably already have CertainTeed materials in your home, or you want them in the new space. Either way, we’ll help you match the right product to the right job, with a written price before any work starts.
Which CertainTeed Models This Applies To
CertainTeed makes a wide range of building products that go into home additions and ADUs. The most common lines we work with in Long Beach include CertainTeed Gypsum Board (standard, moisture-resistant, and fire-rated Type X), CertainTeed Sustainable Insulation (fiberglass batts and blown-in), and CertainTeed exterior products like WeatherBoards siding and Landmark shingles. Each product line has specific compatibility requirements depending on your wall assembly, ceiling height, and Long Beach’s coastal climate zone.
Here’s what matters: not all drywall is created equal for a Long Beach ADU. If you’re building a detached unit within a few miles of the coast, the marine air means you want moisture-resistant board in bathrooms, laundry spaces, and any wall that faces the ocean breeze. CertainTeed’s Moisture and Mold Resistant Gypsum Board is what we spec in those spots. For insulation, the R-value you need depends on whether the space is conditioned. A detached ADU in Long Beach needs R-13 to R-21 in the walls and R-30 to R-38 in the ceiling to pass California’s Title 24 energy requirements. CertainTeed’s Sustainable Insulation batts come in those exact ratings, and they’re made with a formaldehyde-free binder, which matters if you have kids or pets sleeping in the new space.
OEM CertainTeed product versus an aftermarket equivalent: for structural and fire-rated applications, we use CertainTeed products specifically. The Type X fire-rated board is code-required in ADU walls shared with a garage or property line in Long Beach, and we don’t substitute there. For non-structural applications like interior wall finish, there are quality equivalents, but the price difference is small enough that we default to CertainTeed across the board. It keeps the warranty trail clean and the product consistency predictable.
Styles & brands we work with
Signs Your CertainTeed Home Additions & ADU Is Failing
- Sagging or cracking drywall seams in the existing structure. This usually points to foundation movement or moisture intrusion behind the CertainTeed board. In Long Beach, where many homes sit on expansive soil, this can happen slowly over years, and the fix often involves re-taping and re-texturing after addressing the underlying cause.
- Insulation that’s settled or become damp in the walls or ceiling. Blown-in CertainTeed insulation loses R-value over time, especially in older additions where the original install wasn’t dense-packed. If your energy bills climb in August and you feel drafts near the baseboards in winter, the insulation has likely stopped doing its job.
- Musty odor inside the addition or ADU. This indicates moisture trapped behind drywall or within the insulation cavity. In Long Beach’s coastal humidity, a small roof leak or a poorly sealed window can feed mold growth inside the wall cavity before you ever see a stain on the painted surface.
- Visible water staining on the ceiling or around windows. CertainTeed Gypsum Board is not waterproof. Once the paper facing gets wet, it wicks moisture and loses structural integrity. The sooner you catch it, the less demolition is required, which is why we always tell Long Beach homeowners to look up at the ceiling corners after a heavy rain.
- Nail pops or fastener heads pushing through the drywall surface. This is rarely the drywall’s fault. It means the framing behind it has moved or the original fasteners were overdriven. It’s a clean fix when addressed early, and we replace the affected CertainTeed board with new stock that matches the existing thickness.
Replacement Cost & What’s Included
For a full home addition in Long Beach, the installed range is $45,000 to $130,000. A detached ADU runs $90,000 to $220,000. A garage conversion, which often reuses the existing shell and adds CertainTeed drywall and insulation inside, lands between $30,000 and $80,000. If you’re repairing or replacing a specific failed CertainTeed component within an existing space, like re-insulating walls or replacing water-damaged drywall, that work is priced by the square foot or the wall section, and we give you a written line-item number before the crew arrives.
What’s included: materials from named brands with verifiable warranties, the labor to demo and haul away the failed material, installation of the new CertainTeed product to match your existing wall or ceiling thickness, mudding and taping where applicable, texture matching, and a full clean-up. The clean-up is part of the Cedarwell Care Promise: shoe covers at the door, drop cloths on the floors, a photo of the clean-up before the crew leaves. You also get the 365-Day Done Right Promise. If it’s not done right after the job is complete, we make it right. That’s stamped on every project we do in Long Beach.
On any larger addition or ADU project, the price is written before any work starts. Graham Stein, our owner, gives homeowners a written scope of work before a single tool comes out of the truck. The price he writes down on day one is the price on the invoice when we’re done. No estimates that grow after the crew arrives.
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Here’s the honest split. If you’re looking at a small drywall repair in an interior wall, like a doorknob hole or a cracked corner, you can handle that with some patching compound and patience. If you’re dealing with insulation in an exterior wall or ceiling, or any drywall that’s been wet, or anything involving a shared wall with a garage or property line, call us. Wet drywall hides mold. Fire-rated assemblies require specific fastener patterns and board thickness. And getting the wrong R-value in a Long Beach ADU means failing the Title 24 inspection, which means paying for the work twice.
If you’re planning a full addition or ADU, this isn’t a weekend project. It’s permits, foundation, framing, electrical, plumbing, and inspection scheduling. That’s what we do every week in Long Beach. We know the staff at the Long Beach Development Services building, we know which inspectors check what, and we know how to keep the project moving without cutting corners. Call us at (562) 512-7086 and we’ll talk through what you’re planning.
FAQs
CertainTeed drywall and insulation routinely lasts 30 to 50 years when installed correctly and kept dry. In Long Beach’s coastal environment, the variables are moisture exposure and ventilation. A properly flashed wall system with moisture-resistant board in wet areas will perform at the top of that range. If you’re seeing failures in under 15 years, it’s almost always an installation or moisture issue, not a product defect. Call (562) 512-7086 for an assessment and we’ll tell you what’s actually going on.
Usually yes, especially when caught early. A single section of water-stained drywall can be cut out and replaced with new CertainTeed board that matches the existing thickness. Insulation can be topped off or dense-packed into wall cavities without opening the whole wall. What we don’t do is patch over mold or leave compromised structural board in place, because that just creates a bigger problem later. Call us for a free estimate and we’ll give you a repair scope that’s honest about what can stay and what needs to come out.
A single wall section or ceiling patch typically takes one to two days, including texture matching and primer. Re-insulating an existing ADU is usually a one-day job. A full addition or new ADU build runs anywhere from three to six months depending on scope and permitting. We’ll put the timeline in writing at the estimate, along with the price.
For common sizes and ratings, we stock CertainTeed Gypsum Board, moisture-resistant board, and Sustainable Insulation batts on our trucks. Specialty items like Type X fire-rated board in non-standard thicknesses or blown-in insulation bags are ordered per project, usually with a two to three day lead time in Long Beach. If you need something specific, call (562) 512-7086 and we’ll tell you exactly what we have and what we’d need to order.
We also work with other named-brand materials in our remodeling projects, including cabinets from KraftMaid, countertops from Cambria and Silestone, and fixtures from Kohler, Moen, and Grohe. If your addition or ADU is moving into the finish phase, those are brands you can research by name, with warranties that travel with the finished project.
Call Elmstead Remodeling Long Beach
If you have a CertainTeed product that’s failing, or you’re planning an addition or ADU that needs to be done right, call us at (562) 512-7086. You’ll get a live person on the phone, a written price before any work starts, and a crew that treats your home the way they’d treat their own: shoe covers at the door, drop cloths on the floors, quiet tools during rest hours, and pet-safe products wherever there’s a choice. Elmstead Remodeling Long Beach is an independent service provider, not affiliated with CertainTeed, but we know their products inside out and we stand behind our work.
Written by Graham Stein, Owner, Elmstead Remodeling Long Beach at Elmstead Remodeling Long Beach, serving Long Beach and nearby areas.
