What Is Rigid Foam Board Insulation?

Materials, R-Values, and Where It Excels

Rigid foam board insulation is a closed-cell thermal barrier that delivers high R-value per inch, continuous coverage, and exceptional moisture resistance. Belmont Insulation installs all major formulations—EPS (expanded polystyrene), XPS (extruded polystyrene), and polyiso (polyisocyanurate)—selected to match performance goals, budget, and assembly details.

Typical R-values range roughly from R-3.6–4.2 per inch for EPS, R-4.7–5.0 for XPS, and R-5.6–6.5 for polyiso, with compressive strengths and vapor permeance tailored to the application. Used as continuous exterior insulation, over roof decks, on foundation/basement walls, or at slab edges, rigid foam reduces thermal bridging, manages dew points, and creates a durable, stable substrate for cladding systems.

Energy Savings, Comfort, and Moisture Control

By limiting thermal bridging and adding continuous R-value, rigid foam lowers heating and cooling loads, helps stabilize indoor temperatures, and can improve comfort near exterior walls and floors. When seams are sealed, it also contributes to tighter assemblies and fewer drafts.

Closed-cell boards shed bulk water and can act as a vapor retarder in the right location of the wall, helping to prevent condensation within the assembly. With proper detailing—taped seams, integrated flashing, and a code-required thermal barrier where needed—rigid foam supports energy efficiency, durability, and indoor air quality.

From Assessment to Final Seal

Every project begins with a thorough assessment of the building envelope. We identify thermal bridges, evaluate existing assemblies, review ventilation, and determine the foam type, thickness, and placement needed to meet performance targets and applicable codes such as California Title 24.

Installation focuses on precision and continuity: panels are cut to fit, seams are staggered, and boards are mechanically fastened or adhered per substrate. We tape and seal joints, integrate flashings with the weather-resistive barrier, protect terminations, and coordinate with cladding, roofing, or slab details to manage water and vapor.

Interior applications on masonry or basement walls receive foam-compatible adhesives and fire protection as required; roof and exterior retrofits are detailed to maintain drainage planes and ventilation. We finish with quality checks, documentation of materials and R-values, and clear maintenance guidance.

Insulation servces in Long Beach, CA
Insulation servces in Long Beach, CA

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Insulation servces in Long Beach, CA
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Local Expertise And Project Options

Built for Local Codes and Climate

Coastal conditions in Long Beach call for assemblies that balance thermal performance with robust moisture management. We specify corrosion-resistant fasteners, carefully taped seams, and weather-resistive barriers that integrate with rigid foam to handle wind-driven rain while satisfying California Title 24 energy requirements.

From retrofits and ADUs to commercial build-outs, Belmont Insulation delivers rigid foam solutions in Long Beach for exterior continuous insulation, roof recover assemblies, basement and crawl space insulation, and slab-edge protection—engineered for marine air, sun exposure, and year-round comfort.

Get started with a no-obligation consultation in Long Beach. Our team will assess your building, recommend the right foam product and thickness, provide a clear proposal, and schedule efficient installation backed by workmanship warranties and responsive support.

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Fiberglass Insulation
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Attic Insulation Install and Removal
Mineral Wool
Rigid Foam Board Insulation
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Insulation servces in Long Beach, CA
Insulation servces in Long Beach, CA
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