The Challenge
Patrick wanted a modern, comfortable home that was economical to build and energy-efficient to run.
There were various factors to consider in relation to managing moisture and condensation. Metal containers generate considerable amounts of condensation and any moisture trapped between the insulation and steel walls could cause rust, mould and structural damage over time. It was important to identify an insulation solution that would prevent moisture penetration and have adequate airflow to manage humidity. This would allow any moisture to escape, rather than pooling.
Our Solution
We recommended the use of Walltite Spray Foam Insulation. This is often used to reduce heat loss within existing and new build cavity walls consisting of masonry inner and outer leaf construction - a traditional building method commonly used in the UK and Ireland where two separate walls (leaves) are built with a gap (cavity) between them.
Walltite Spray Foam Insulation is also beneficial in new build construction when its resistance to flood water is of importance. It stabilises the wall by adhering to the inner surfaces of the cavity and provides a continuous structural connection between the two leaves. It has excellent resistance to driving rain and can be installed in all geographical exposure zones.
Walltite insulation is installed as a liquid through a pattern of 12mm pre-drilled holes. It then expands within the cavity to gently fill each void eventually setting as a rigid polyurethane high-density insulation.
BASF Walltite is both BBA (British Board of Agrément) and NSAI (National Standards Authority of Ireland) certified and is available in both spray and injection formulations.
Our team carried out the spray foam installation project for Patrick. The foam insulation followed the contours of the metal containers that formed the basis of the construction. We applied 125mm of Walltite Spray Foam to achieve airtight U-Value of 0.20 W/m2k.
The Results
The installation of Walltite Spray Foam insulation to the cavity walls and roof of the shipping container home resulted in a number of positive outcomes for homeowner, Patrick Bradley:
Condensation Control and Moisture and Mould Prevention: Walltite's closed-cell formula adhered directly to the steel walls, creating an airtight vapour barrier which is preventing moisture from reaching the metal surface—critical for avoiding rust, corrosion, and mould in container homes.
Superior Insulation Performance: The spray foam insulation delivered high R-values in minimal thickness, maximising usable interior space and keeping the home comfortable in extreme heat and cold.
Seamless Coverage: It perfectly filled the corrugated ridges of the container walls, eliminating air gaps and thermal bridging that occur with rigid foam boards—there are no cold spots or heat loss through the metal frame.
Air Sealing: It created a completely airtight envelope, dramatically reducing heating and cooling costs. Container homes are naturally drafty at seams and doors, but the spray foam insulation has eliminated this issue.
Structural Benefits: The insulation added rigidity to the container walls, improving structural integrity when applied to all interior surfaces.
Energy Efficiency: The spray foam insulation reduced heating and cooling costs by up to 50% compared to uninsulated or poorly insulated containers, making the home economical for Patrick to maintain long-term.
Quick Installation: Our professional spray foam application is faster than installing multiple layers of rigid boards, vapour barriers, and battens. This reduced labour costs and construction time, helped Patrick to deliver this aspect of the project within budget.
Our Walltite insulation project has been covered by TV’s Grand Designs show and was described by presenter Kevin McCloud as the “right solution”. Watch the feature.
Patrick Bradley’s house has since won 2 RIBA awards (Royal Institute of British Architects).
