Owens Corning Home Additions & ADU Nationwide

Owens Corning Home Additions & ADU: The Sherman Oaks Owner’s Guide

We stock and install Owens Corning-compatible insulation systems, roofing components, and weather barriers for home additions and ADU projects in Sherman Oaks, with typical installed pricing from $45,000 to $130,000 for full additions and $90,000 to $220,000 for detached ADUs. Most Owens Corning material orders arrive within 48 hours through our distributor network, and we keep common R-13 through R-38 batts and Duration shingles in regional stock for same-week starts. Homeowners usually discover a problem when an existing addition’s temperature lags the main house by 8-10 degrees, or when an inspector flags the original fiberglass install as compressed below its labeled R-value, a condition we see regularly in 1980s-era Sherman Oaks room additions near the Galleria corridor.

Call (213) 221-0788

Which Owens Corning Models This Applies To

Owens Corning produces three product families relevant to additions and ADUs: the EcoTouch PINK Fiberglas insulation line (R-13 through R-38, unfaced and kraft-faced), the Duration and Oakridge shingle systems for roof tie-ins, and the Foamular rigid foam boards used for foundation perimeter insulation. The critical compatibility check is the facing: kraft-faced batts are vapor-retarder rated and belong on the heated side of exterior walls in Sherman Oaks’ climate zone 9, while unfaced batts require a separate poly vapor barrier. We verify the existing wall cavity depth before ordering, because a 2×4 wall takes R-13 or R-15, and a 2×6 wall takes R-19 or R-21; forcing R-19 into a 2×4 cavity compresses the fiberglass and drops the effective R-value by 15-20 percent. For roofing tie-ins, we match the existing Owens Corning shingle color code, not just the series name, because Duration in Desert Tan from 2019 carries a different granule blend than the 2024 run. We are an independent contractor and not affiliated with Owens Corning.

Signs Your Owens Corning Home Additions & ADU Is Failing

• Uneven temperatures between rooms. The original insulation has settled or was installed with gaps around electrical boxes and framing members, creating thermal bypasses. In Sherman Oaks, we see this most often in second-story additions where the ceiling batt was pushed aside during ductwork installation and never restored.
• Visible moisture or mold on interior walls. This indicates the vapor retarder was installed on the wrong side of the wall, or kraft facing was used in a bathroom addition without an additional vapor barrier. Owens Corning kraft facing is not rated for high-humidity environments.
• Shingle granules collecting in gutters after a roof tie-in. The Owens Corning Duration shingles on the new section may be a different nailing zone specification than the original, or the installer missed the reinforced fabric strip. We check the SureNail band alignment on every repair.
• Drafty outlets and baseboards. Fiberglass batts were cut too narrow for the stud bay, leaving a 1/2-inch gap that convection fills with outside air. The gap doesn’t close itself; it widens as the batt settles over years.
• Energy bills rising without rate increases. The addition’s thermal envelope has degraded, often from compressed insulation in sloped ceilings where the installer used R-30 in a 2×8 rafter bay that only accommodates R-25 when properly vented. Compressed fiberglass loses R-value proportionally to its thickness reduction.

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Replacement Cost & What’s Included

The range depends on three factors: whether we’re matching existing materials or upgrading the entire thermal envelope, the accessibility of the cavity (finished drywall adds removal and replacement labor), and whether the original install included fire-blocking that must be preserved per LA City code. Under Clause 1 of the Haven Standard, you receive a written price before any work starts, and no change proceeds without a signed change order. Every project carries our 365-Day Done Right Promise.

DIY or Call Us?

An owner can safely check three things: verify the Owens Corning product code printed on any exposed facing, measure cavity depth with a tape measure and flashlight, and photograph any visible moisture staining for documentation. What goes wrong with DIY insulation work is the sequencing: vapor barriers installed after the fact trap existing moisture, batts cut with a utility knife leave compressed edges that lose R-value, and attic kneewalls in Sherman Oaks additions often lack the required 1-inch vented airspace that prevents summer heat buildup. The fiberglass itself is not hazardous to handle with gloves and long sleeves, but the thermal imaging and blower-door testing we perform after installation is what verifies the fix actually worked. Measure twice, write it down, then build it. Call (213) 221-0788 when you’re ready for a written estimate.

FAQs

Why Sherman Oaks Owners Choose Rowan for Owens Corning Work

We’ve built additions and ADUs across the San Fernando Valley since 2007, and Sherman Oaks specifically for several years running, including projects near the Galleria corridor and the residential streets off Ventura Boulevard. Grant Rowan studied construction technology at Los Angeles Valley College in Valley Glen before founding the company, and that training in reading structural drawings shows up in how we plan every tie-in and envelope detail. Our crews are background-checked and uniformed; a live person answers calls 24/7; and every visit includes a documented photo record as standard, not an upgrade. We also stock parts and materials for KraftMaid, Cambria, and Silestone installations, giving us sourcing depth that keeps written quotes honest rather than padded for uncertainty.

Call (213) 221-0788 to schedule your free estimate. We’ll review your existing Owens Corning installation, identify the exact product codes needed, and deliver a written price before any work starts - always, under Clause 1 of the Haven Standard.

Written by Grant Rowan, Owner, Rowan Construction Group Sherman Oaks at Rowan Construction Group Sherman Oaks, serving Sherman Oaks and nearby areas.