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Owens Corning Home Additions & ADU: The Jacksonville Owner's Guide
If you're planning a home addition or ADU in Jacksonville and want Owens Corning insulation, roofing, or building-envelope products named in the scope, we install them and write the exact product names into your contract. A full home addition in Jacksonville typically runs $45,000–$130,000, and an ADU construction project runs $90,000–$220,000 depending on size, foundation work, and finish level. Most Jacksonville homeowners reach out after realizing their existing space no longer works, and they want to know whether Owens Corning materials make sense for the new square footage before they commit.
Here's the reality we walk Jacksonville families through every month: Owens Corning is not a single part you swap out. It's a material system – insulation batts, air-sealing products, roof shingles, and underlayment – and the failure homeowners experience is usually in the building envelope itself. A room that won't hold temperature, a roof that leaks after a storm, or an attic that's sweating in Florida humidity. The fix is rarely "replace one part." It's usually "design the addition correctly from the start, or fix what the last contractor skipped." That's where we come in.
We are an independent Jacksonville remodeling contractor, not affiliated with Owens Corning. We do, however, specify and install their products by name – and we also work with KraftMaid, Cambria, and Silestone for the interior finishes that complete the job.
Which Owens Corning Models This Applies To
Owens Corning product lines break into a few families, and the compatibility details matter when you're adding square footage in Jacksonville's climate. For insulation, the two you'll see most in local additions are the EcoTouch PINK fiberglass batts and the FOAMULAR XPS rigid foam board. EcoTouch comes in R-13, R-19, R-30, and R-38, and the R-value you need depends on where it's going – R-30 to R-38 in attics, R-13 to R-19 in walls. FOAMULAR is the product we lean on for exterior sheathing and under-slab work in ADUs because it resists moisture, which matters when your addition sits on a Jacksonville lot where the water table runs high in summer.
For roofing on the addition, Owens Corning Duration and Duration FLEX shingles are the two series most Jacksonville homeowners choose. The FLEX line is built with an SBS-modified asphalt layer that gives it better impact and wind performance – relevant here because Duval County sits in a high-wind zone, and your insurance company may ask what's on the roof. If the original part of your house has Duration shingles and you want the addition to match, you need the exact color lot, not just the color name – Owens Corning runs multiple lots of the same named color, and a mismatch shows up in full sun. We can pull a sample from the existing roof and match it before ordering.
The compatibility gotcha we see most often: homeowners reuse old attic insulation in the new space to save money. That's a false economy in Jacksonville. Insulation loses R-value when it's compressed, damp, or dust-filled, and moving it into new framing rarely meets current Florida Building Code energy requirements. We write it out of our scopes.
Styles & brands we work with
Signs Your Owens Corning Home Addition or ADU Is Failing
- Rooms at the new end of the house run 6–10 degrees warmer than the original side. This usually means the insulation was under-specified, gapped, or compressed during install. In Jacksonville's August heat, you'll feel it by 3 p.m. and the AC will run longer every day.
- Attic sheathing shows dark streaks or mold bloom around the eaves. That's a ventilation problem, not always an insulation problem – but the two work together. Owens Corning attic baffles and proper soffit-to-ridge airflow matter as much as the R-value.
- The ADU roof leaks within a year or two of completion. Florida wind-driven rain finds every nail-pop and badly flashed valley. This is a workmanship failure, and it's the kind of thing our 365-Day Done Right Promise exists to catch.
- You can see daylight through gaps where the addition wall meets the original house. The building envelope wasn't sealed. Air leaks here mean moisture, pollen, and Jacksonville's summer humidity enter the wall cavity year-round.
- Insulation batts are sagging or falling away from the floor joists in a raised ADU. Fiberglass batts must be friction-fit or mechanically fastened. In a humid crawlspace, they also need a vapor barrier. If they're drooping, they're not insulating.
See the difference
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After
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AfterReplacement Cost & What's Included
In Jacksonville, a full home addition runs $45,000–$130,000. An ADU construction project runs $90,000–$220,000. The spread is driven by square footage, foundation type (slab-on-grade vs. raised), whether the roof ties into the existing house or gets its own line, and the interior finish level – a kitchenette with Cambria countertop and KraftMaid cabinets costs more than a simple bedroom suite.
| Project | Jacksonville Price Range |
|---|---|
| Home Addition | $45,000–$130,000 |
| ADU Construction | $90,000–$220,000 |
| Garage Conversion | $30,000–$80,000 |
| Countertop Installation (Cambria/Silestone) | $2,000–$6,500 |
| Cabinet Installation (KraftMaid) | $4,000–$13,000 |
Our scopes list materials by name – Owens Corning EcoTouch, FOAMULAR, Duration shingles – and labor in staged line items. No allowance line items that quietly grow. The price Graham Stein writes is the price you approve before any work starts, and the 365-Day Done Right Promise covers the finished project. If something fails because we missed it, we make it right.
DIY or Call Us?
You can assess a few things yourself. Walk the room on a hot afternoon and note where the heat concentrates. Check the attic access for daylight gaps. Look at the roof from the ground after a storm for lifted shingles. That's useful information to bring to us.
What you should not do is tear into the building envelope. Cutting into exterior walls, pulling insulation, or re-flashing a roof valley on a two-story Jacksonville addition is dangerous work – heights, nail guns, and Florida summer heat do not mix with a weekend warrior setup. If you suspect a failed Owens Corning install, call (904) 643-6243. We'll send a background-checked crew, drop cloths and shoe covers included, and you'll get a written price before anything is touched.
FAQs
Owens Corning fiberglass insulation should last the life of the home when it stays dry and undisturbed – typically 50+ years. In Jacksonville's humidity, failures come from moisture intrusion or poor installation more often than material breakdown.
Yes, in many cases. A section of sagging batt insulation can be re-fit or replaced, and a leaked roof valley can be re-flashed without replacing the whole roof. The question is whether the rest of the envelope is sound. Call (904) 643-6243 and we'll tell you honestly after looking at it.
A typical home addition takes 3–6 months from permitting to final walk-through, depending on size and finish level. An ADU usually runs 4–8 months. The written quote includes the schedule, so you'll know what to expect before we start.
We order per job so the product is fresh, the lot numbers match, and the warranty paperwork is clean. That means no warehouse stock sitting in Jacksonville heat and humidity before it goes into your walls. If you have a specific Owens Corning product in mind, call (904) 643-6243 and we'll confirm availability and lead time.
Name the material, name the day, name the price – then there is nothing left to wonder about. We're Elmstead Remodeling Jacksonville, and we've been writing scopes in plain language across Jacksonville, including additions and ADUs in Avondale and nearby neighborhoods, for years. Call (904) 643-6243 to schedule your free estimate. A live person answers, day or night.
Written by Graham Stein, Owner, Elmstead Remodeling Jacksonville at Elmstead Remodeling Jacksonville, serving Jacksonville and nearby areas.
