Wood Fiber Insulation in a Steel Stud Acoustic Assembly: Inside UMaine’s GEM Factory of the Future

Wood Fiber Insulation in a Steel Stud Acoustic Assembly: Inside UMaine’s GEM Factory of the Future

TimberBatt Acoustic wood fiber insulation was installed in steel stud acoustical partitions at the University of Maine’s GEM Factory of the Future — an $82 million, 50,000-square-foot advanced manufacturing research facility in Orono, Maine. In tested steel stud assemblies, TimberBatt achieves STC 53, matching mineral wool and outperforming fiberglass by three points. It also satisfies Build America, Buy America (BABA) domestic-content requirements, which was a threshold condition for consideration on this federally funded project.

Project at a glance

What is the GEM Factory of the Future?

The Green Engineering and Materials (GEM) building — also referred to as Green Energy & Materials — is a 50,000-square-foot research and education facility on the University of Maine’s Orono campus. It houses the university’s Factory of the Future: a large-format additive manufacturing test bed built around AI-enabled 3D printing and computational materials science, operated as a partnership between UMaine’s Advanced Structures and Composites Center, the Maine College of Engineering and Computing, and the College of Liberal Arts and Sciences.

The $82 million project drew federal, state, and philanthropic funding, and the building itself is framed in mass timber — a deliberate choice to demonstrate the renewable materials the facility exists to advance.

That framing decision matters for the insulation story. A building constructed to showcase bio-based materials creates an obvious question about what goes inside the walls. Specifying a petrochemical or mineral batt behind a mass timber structure would have undercut the premise.

Why did the project team specify wood fiber insulation?

Three constraints converged, and TimberBatt Acoustic satisfied all three.

1. Acoustic performance was the design requirement. These were acoustical partitions in a facility that mixes high-bay manufacturing with classrooms, offices, and immersive learning environments. The assembly had a sound isolation target, and the cavity insulation had to hit it.

2. Domestic content was non-negotiable. Federal funding brought Build America, Buy America requirements with it. Products that couldn’t demonstrate compliance were not considered — the specification gate closed before performance was even evaluated.

3. The material story had to match the building. Both the owner and the architect brought wood fiber insulation to the project independently. In a facility whose research mission is bio-based materials, wood fiber cavity insulation inside a mass timber frame is a coherent specification rather than a compromise.

How does wood fiber insulation perform acoustically in a steel stud wall?

In a tested steel stud assembly, TimberBatt achieves STC 53.

Tested assembly: 3-5/8″ metal studs at 16″ o.c. · 3.5″ batt insulation · resilient channel on source side · single layer 5/8″ Type X gypsum board both sides.

Read that table honestly: TimberBatt matches mineral wool and beats fiberglass by three points. Three STC points is a real, audible difference at the partition scale — but the headline here isn’t that wood fiber wins on acoustics. It’s that wood fiber ties the acoustic benchmark material while also being bio-based, vapor-open, domestically manufactured, and BABA compliant.

For a specifier, that reframes the decision. If mineral wool and wood fiber land at the same STC in the same assembly, acoustics stops being the tiebreaker and everything else starts mattering.

Why dense wood fiber performs this way: sound isolation in a cavity depends on the insulation’s ability to convert acoustic energy into heat through friction as air moves through the fiber matrix. Density and airflow resistance drive that conversion. TimberBatt’s wood fiber structure gives it the density and tortuous fiber path that light, low-density batts lack — which is the same reason fiberglass trails by three points in the identical assembly.

What is STC, and what does an STC 53 wall actually sound like?

Sound Transmission Class (STC) is the industry-standard single-number rating for how effectively a wall, floor, or ceiling assembly blocks airborne sound. Higher numbers block more.

At STC 53, normal conversation on the other side of the partition is not intelligible — you may perceive that someone is speaking, but not what they’re saying. That’s the performance band typically specified for classrooms adjacent to circulation, offices requiring speech privacy, and spaces buffering mechanical or manufacturing noise.

One critical caveat: STC is a property of the whole assembly, not of the insulation. The batt is one variable among framing type, spacing, gypsum layers and thickness, decoupling, and sealing. Swapping insulation into an otherwise unchanged assembly moves the number a few points. Changing the assembly moves it much further.

What is NRC, and why does it matter alongside STC?

Noise Reduction Coefficient (NRC) measures absorption — how much sound energy a material soaks up rather than reflects — on a scale where 1.00 represents complete absorption of incident sound. STC measures what gets blocked between two rooms; NRC measures what gets soaked up within one.

TimberHP wood fiber products deliver NRC values up to 1.15

Both ratings matter, and they solve different problems:

• STC → the classroom next door can’t hear the manufacturing bay.
• NRC → the manufacturing bay itself isn’t a reverberant echo chamber.

In a facility that combines high-bay industrial space with teaching environments, a cavity insulation that performs on both axes reduces the need for separate acoustic treatment systems.

Does TimberBatt meet Build America, Buy America requirements?

Yes. TimberBatt met BABA Federal Program requirements on the GEM project — and on this project, that was a prerequisite for consideration, not a bonus.

The Build America, Buy America Act requires that iron, steel, manufactured products, and construction materials used in federally funded infrastructure projects be produced in the United States. For project teams working on federally funded work, this collapses the eligible product list fast, and it does so before performance is evaluated. A product that outperforms the competition on every metric is still ineligible if it can’t demonstrate domestic content.

TimberHP manufactures at its facility in Madison, Maine, using wood fiber from the surrounding forest resource — which is why the domestic content question resolves cleanly.

If you’re specifying for a federally funded project: the BABA question should be your first filter, not your last. Contact TimberHP for project-specific documentation.

How does TimberBatt install in steel stud framing?

TimberBatt is manufactured in dedicated steel stud dimensions, so it friction-fits into metal framing without the field modification that wood-stud-only batts require.

At 3.5″, that’s R-14 in the cavity; at 6″, R-24. Note that steel studs conduct heat, so the assembly R-value in a thermally bridged steel stud wall is substantially lower than the cavity R-value — which is why steel stud assemblies designed for thermal performance pair cavity insulation with continuous exterior insulation. On an interior acoustical partition like the GEM assembly, that thermal bridging penalty is not the governing concern; sound isolation is.

Contractors moving from mineral wool will find the handling familiar — TimberBatt cuts cleanly with a serrated blade and holds its shape in the cavity. It does not itch or shed the way fiberglass does, which matters on a project with this much square footage of partition work.

What else does the assembly need to hit its acoustic target?

Insulation is necessary but not sufficient. On projects where a wall tests well in the lab and disappoints in the field, the cause is almost always one of these:

Flanking paths. Sound routes around the partition rather than through it — over the ceiling plenum, under the floor, through shared structure, or through continuous ductwork. A partition that stops at the ceiling grid instead of running to deck will underperform its rating no matter what’s in the cavity.

Penetrations. Back-to-back electrical boxes, unsealed conduit, and un-gasketed sleeves each open a direct acoustic path. A small unsealed gap degrades an assembly’s real-world performance measurably.

Perimeter sealing. Acoustical sealant at the head, base, and jambs is what separates rated performance from theoretical performance.

Decoupling. The resilient channel in the GEM tested assembly isn’t incidental. Mechanically separating the gypsum from the studs on the source side is doing significant work in that STC 53 result.

Get those right, and the cavity insulation delivers what the lab test promised.

Key takeaways

• TimberBatt Acoustic performed in steel stud acoustical assemblies at UMaine’s $82M GEM Factory of the Future, a 50,000 sf mass timber research facility in Orono, Maine.
• Tested steel stud assembly: STC 53 — equal to mineral wool, three points above fiberglass.
• Build America, Buy America compliance was the gating requirement, not a differentiator after the fact.
• Wood fiber delivers both isolation (STC) and absorption (NRC) performance from a single bio-based, domestically manufactured product.
• Owner and architect independently brought wood fiber to the project — a signal that material transparency is moving from preference to specification driver on institutional work.

Ready to incorporate TimberBatt into your next project? 

Review the product specifications and assembly details, or contact TimberHP for technical guidance, application support, or answers to your questions.