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Essential Tips for Sealing Joints in Modular Refrigerated Containers
2026-07-24
With the surging demand for cold storage facilities at produce origins and temporary mobile cold storage units, modular solutions involving the combination of multiple refrigerated Containers are becoming increasingly popular. Many clients wonder: how can multiple refrigerated containers be joined side-by-side to form a single, unified cold storage space while preventing cold air leakage, water seepage, and efficiency loss? Today, using a real-world example from one of our clients, we will walk you through the nine-step assembly process—designed to ensure structural stability, airtight thermal insulation, and durable waterproofing.
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Step 1: Precision positioning and base preparation—ensuring perfect alignment.
A successful assembly relies on the containers being perfectly level and plumb. During construction, specialized positioning plates are first laid on a flat, hardened surface. The 20ft/40ft refrigerated containers are then hoisted and placed sequentially onto these plates. The spacing between containers is meticulously adjusted to ensure they are perfectly aligned horizontally, vertically, and in depth, eliminating any height discrepancies or misalignment.
A successful assembly relies on the containers being perfectly level and plumb. During construction, specialized positioning plates are first laid on a flat, hardened surface. The 20ft/40ft refrigerated containers are then hoisted and placed sequentially onto these plates. The spacing between containers is meticulously adjusted to ensure they are perfectly aligned horizontally, vertically, and in depth, eliminating any height discrepancies or misalignment.
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Step 2: Installing Double-Layer Rubber Seals—Isolating Internal and External Air
Sealing is the heart of the entire process. We employ a dual-barrier structure featuring an outer long seal and an inner short seal to lock in cold air at the source. This double-layer seal acts as a dual barrier: it prevents hot, humid outdoor air from entering and stops cold indoor air from escaping, thereby significantly reducing the load on the Refrigeration Units.
Sealing is the heart of the entire process. We employ a dual-barrier structure featuring an outer long seal and an inner short seal to lock in cold air at the source. This double-layer seal acts as a dual barrier: it prevents hot, humid outdoor air from entering and stops cold indoor air from escaping, thereby significantly reducing the load on the Refrigeration Units.
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Step 3: Locking with Specialized Corner Connectors for Structural Rigidity
Seals alone cannot secure the containers; specialized corner connectors are required to lock adjacent units together. When multiple containers are arranged side-by-side, connectors are installed at both the top and bottom corners of every adjacent pair. This firmly binds the containers into a single, unified structure, preventing relative movement and protecting the internal sealing strips from being pulled apart or cracking.
Seals alone cannot secure the containers; specialized corner connectors are required to lock adjacent units together. When multiple containers are arranged side-by-side, connectors are installed at both the top and bottom corners of every adjacent pair. This firmly binds the containers into a single, unified structure, preventing relative movement and protecting the internal sealing strips from being pulled apart or cracking.
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Step 4: Filling Bottom Gaps with PE Thermal Breaks to Block Ground-Level Thermal Bridging
Gaps at the bottom of the containers are prone to forming thermal bridges. Since steel conducts heat, this can lead to extensive condensation or icing on the container exteriors; therefore, we use PE (polyethylene) blocks to provide thermal insulation and break the thermal bridge.
Gaps at the bottom of the containers are prone to forming thermal bridges. Since steel conducts heat, this can lead to extensive condensation or icing on the container exteriors; therefore, we use PE (polyethylene) blocks to provide thermal insulation and break the thermal bridge.
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Step 5: Covering the bottom with aluminum plates for waterproofing and impact protection
An aluminum cover plate is installed over the PE thermal break blocks, fully covering the entire length of the bottom joint. Apply the specialized adhesive evenly along the joints to secure the aluminum cover plate. The metal cover plate not only prevents sewage infiltration but also protects the internal insulation and barrier components, safeguarding the sealing structure against impact damage.
An aluminum cover plate is installed over the PE thermal break blocks, fully covering the entire length of the bottom joint. Apply the specialized adhesive evenly along the joints to secure the aluminum cover plate. The metal cover plate not only prevents sewage infiltration but also protects the internal insulation and barrier components, safeguarding the sealing structure against impact damage.
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Step 6: Fill the top gap with foam insulation blocks to eliminate paths for cold air leakage.
A long, narrow gap exists between the two crossbeams at the top of the enclosure; this must be completely filled with foam insulation blocks, ensuring no voids or discontinuities. An aluminum top cover is installed over this and secured to the PVC top beams of the enclosure, providing dual-layer protection that resolves the dual issues of cold air leakage and rainwater infiltration at the top.
A long, narrow gap exists between the two crossbeams at the top of the enclosure; this must be completely filled with foam insulation blocks, ensuring no voids or discontinuities. An aluminum top cover is installed over this and secured to the PVC top beams of the enclosure, providing dual-layer protection that resolves the dual issues of cold air leakage and rainwater infiltration at the top.
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Step 7: Horizontal sealing at the top interior—the first layer of airtight protection.
A PVC horizontal sealing panel is installed to provide internal insulation and airtightness; it covers the seams where the interior ceiling panels join, preventing cold air from escaping upward through the joints and minimizing temperature gradients within the unit.
A PVC horizontal sealing panel is installed to provide internal insulation and airtightness; it covers the seams where the interior ceiling panels join, preventing cold air from escaping upward through the joints and minimizing temperature gradients within the unit.
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Step 8: Vertical edge sealing and finishing—complete sealing of sidewall gaps.
Sealing panels are secured over the vertical joints at the front and rear of the unit, covering the seam locations on the interior sidewalls.
All internal corner joints and crevices are fully sealed, creating a completely airtight and insulated space within the unit.
Sealing panels are secured over the vertical joints at the front and rear of the unit, covering the seam locations on the interior sidewalls.
All internal corner joints and crevices are fully sealed, creating a completely airtight and insulated space within the unit.
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Step 9: Cleaning, final sealing, comprehensive leak testing, and acceptance.
Following installation, the project proceeds to final inspection: cleaning away dust, touching up adhesive, installing specialized connectors at corner-post joints, inspecting all sealed areas, and activating the refrigeration system. The installation is deemed successful if the cooling rate is satisfactory, the system operates without anomalies, and no significant condensation forms on the exterior walls.
Following installation, the project proceeds to final inspection: cleaning away dust, touching up adhesive, installing specialized connectors at corner-post joints, inspecting all sealed areas, and activating the refrigeration system. The installation is deemed successful if the cooling rate is satisfactory, the system operates without anomalies, and no significant condensation forms on the exterior walls.
Our container factory manufacturing facility possesses extensive experience in the design and production of modular refrigerated containers, having successfully delivered over a hundred orders. Whether you require a solar-powered refrigerated container cold room or other similar cold storage solutions, we can provide professional design and manufacturing services. If you are interested in this type of project, please feel free to contact us.