Havelock Wool Insulation

The van insulation conversation usually comes down to three options: closed-cell spray foam, fiberglass batts, and wool. Each has its advocates. Here's why OZK installs wool — and why the alternatives create problems that show up months or years after the build is done.

Closed-cell spray foam has the highest R-value per inch, which makes it sound ideal on paper. But spray foam is a vapor barrier — it seals the metal wall completely. In a house, that's fine. In a van, it creates a problem. Moisture that gets behind the foam — and it will, through rivets, seams, door gaps, and any imperfection in the spray application — has nowhere to go. It sits against the bare metal, invisible and inaccessible, corroding your van from the inside. We've seen two-year-old spray foam builds come into our shop with rust damage that required panel replacement. Spray foam also bonds permanently to the metal. If you ever need to access wiring, fix a rust spot, or modify any system behind the walls, you're chiseling through hardened foam. It's a one-way decision with irreversible consequences.

Fiberglass batts are cheap and widely available, which is why they show up in budget builds. The problem is that fiberglass absorbs moisture and holds it — but unlike wool, it doesn't release it. Wet fiberglass loses its thermal performance, compresses permanently, and becomes a breeding ground for mold. It also sheds microscopic glass fibers into the air — a health concern in a house with proper HVAC filtration, and a serious concern in a 60-square-foot living space with no air filtration system. In the enclosed environment of a van, fiberglass is a material designed for a completely different application being forced into one it wasn't built for.

Havelock Wool solves the fundamental problem that both alternatives create: what happens when moisture meets insulation inside a metal vehicle. Wool absorbs it, holds it harmlessly, and releases it when the air dries out — no rot, no mold, no loss of performance. It's breathable, which means the wall cavity behind it can dry naturally. It doesn't bond to the metal, so you maintain access to the van shell for future repairs or modifications. And it doesn't shed harmful particles into your breathing air. The R-value per inch is slightly lower than spray foam, but the real-world thermal performance — factoring in moisture management, longevity, and the absence of hidden damage — is superior in a van application.

Havelock Wool is a superior insulation material, but material alone doesn't determine outcomes — installation does. A van's interior is not a flat wall with uniform stud bays. It's a complex geometry of corrugated metal panels, structural ribs, factory wiring harnesses, mounting points, and irregular cavities that vary by van platform, wheelbase, and roof height. Getting wool insulation right means understanding these geometries and filling them completely — without compression that reduces R-value, without gaps that create thermal bridges, and without interfering with systems that need to remain accessible.

OZK's installation process starts with vapor management. Before any wool goes in, we assess the van's specific condensation patterns — where moisture collects in the ribs, where factory seams allow air infiltration, and where thermal bridges exist between the interior and the metal shell. We address these areas first, ensuring the wool insulation works with the van's natural airflow rather than against it. This is the step that DIY installations almost universally skip, and it's the step that determines whether your insulation performs for a decade or develops problems in year two.

Coverage is the other critical factor. A van's metal shell has dozens of thermal bridges — points where metal spans from the exterior to the interior without insulation, conducting heat and cold directly through the wall. The structural ribs, roof bows, door frames, and floor channels are all thermal bridges. Professional installation means insulating these areas as thoroughly as the flat panels, using cut-to-fit wool pieces that fill every cavity, wrap every rib, and eliminate the cold spots that cause localized condensation. It's painstaking work that requires knowledge of the specific platform — where the hidden cavities are, what needs to stay accessible, and how the insulation integrates with the wall panel system that goes over it.

Insulation isn't a single product — it's a system. At OZK, Havelock Wool is the core thermal and moisture-management layer, but it works in concert with other components to create a complete interior environment. The system starts at the metal skin and builds inward, with each layer serving a specific purpose in the overall thermal, acoustic, and moisture strategy.

Layer 1: Sound Deadening. Lizard Skin ceramic insulation coating or butyl-based sound deadening is applied directly to the bare metal shell. This layer serves two functions — it reduces vibration and resonance in the metal panels (eliminating the "tin can" effect that makes cargo vans loud), and it adds a base layer of thermal resistance at the metal surface. Sound deadening is applied strategically to the largest flat panels where resonance is worst: the floor, the side walls, the ceiling, and the doors.

Layer 2: Havelock Wool. The wool fills the cavity between the metal shell and the interior panels — walls, ceiling, and floor. Wool is cut and fitted to the specific geometry of each section, filling corrugations, wrapping ribs, and packing every void without over-compression. The goal is continuous, even coverage with no gaps and no compressed sections. In the floor, wool is installed between the subfloor supports, insulating the largest thermal surface in the van — the one in direct contact with cold ground, hot pavement, or whatever you're parked on.

Layer 3: Panel Systems. Adventure Wagon, Lost HiWay, or custom panels go over the wool, creating the finished interior surface. The panel mounting system is designed to maintain a small air gap between the wool and the panel face — allowing the wool to breathe and release absorbed moisture into the interior air. This air gap is a critical design detail that most DIY builds miss. Without it, you lose the moisture- buffering capability that makes wool superior to rigid foam alternatives.

OZK installs Havelock Wool insulation on all three major van platforms we support. Each platform has different interior geometries, rib patterns, and insulation requirements — and our team knows the specific techniques for each from hundreds of completed installations.