Spray Foam Insulation For Soffit Insulation

Enverge Spray Foam Insulation is perfect for concrete soffit insulation, concrete slab insulation, metal deck insulation and crawlspace insulation. Its seamless, monolithic insulation layer and strong substrate adhesion make it the first choice for insulating concrete. Unlike pre-manufactured insulation materials, Enverge Spray Foam Insulation can be installed without mechanical fixings or air gaps, which helps speed up the installation process and reduces overall space. To achieve the required fire rating, Enverge Spray Foam Insulation can be covered with a spray-applied intumescent coating to meet a Euroclass B-s1-d0 rating.

Enverge Spray Foam Soffit Insulation Benefits

Concrete Soffit Insulation

In most circumstances, Enverge Nexseal LE Closed Cell spray foam insulation provides the best adhesion and dimensional stability for concrete soffit insulation. It has one of the lowest thermal conductivities per inch compared to many other types of insulation material. When spray-applied by an experienced and professional installer, it can look neat. Enverge Nexseal LE Closed Cell spray foam insulation also offers excellent resistance to moisture and, in some circumstances, can be classed as a vapour retarder. Enverge Sucraseal Open Cell spray foam insulation can also be suitable in some cases. Still, it may require additional vapour control layers, and the end appearance will not be as neat as the closed cell variant. Our technical department provides professional specifications for each project on a case-by-case basis, and we’re sure to design the correct system for a concrete soffit insulation project.

Fast Install





Strong Adhesion

Concrete Soffit Insulation Solutions

Enverge Spray Foam insulates concrete soffits to modern airtight standards to meet thermal targets, low running costs and reduced carbon emissions. Many new and existing buildings contain concrete soffits or slabs that separate a cold space from a heated area. When left untreated, condensation can occur on the slab through surface humidity, where dampness, mould and condensation may develop. Additionally, poorly insulated concrete soffits will experience heat loss and may cause occupants to suffer uncomfortable living or working environments. Spray-applied in layers of between 25mm to 100mm and beyond, Enverge Nexseal LE Closed Cell spray foam insulation helps to meet thermal targets whilst providing a robust, durable and reliable insulation system that will last the life of the building. In contrast to pre-manufactured insulation materials, Enverge Nexseal LE does not require mechanical fixing and can be a more cost-effective and low-disruption alternative.

Soffit Insulation Products

Check our Enverge BBA-Certified Spray Foams For Soffit Insulation

The Enverge range of spray foams include leading brands, Sucraseal Open Cell and Nexseal Closed Cell. Utilising recycled materials, manufactured sustainably with the environment in mind and containing HFO, water-based blowing agents, Enverge products offer thermal, airtightness and durability.

This low exothermic, high-lift closed cell foam boasts a fast installation time, offers incredible thermal performance and improves the structural integrity of a building. Loved by installers for its fast rise, Nexseal is ozone-friendly and holds BBA Certification.

One of the leading open cell foam systems now available in the UK. Sucraseal combines peace of mind British Class 1 fire safety with exceptional thermal performance and is fully certified by the BBA. Sucraseal is installed exclusively by ThermoFoam-approved contractors only.

Soffit Insulation Customers

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How We Help You With Soffit Insulation


Get in touch today to get the ball rolling


Let us specify the requirements for your project​


We’ll provide you with a budget price range


Use one of our ThermoFoam-approved installers


Once installed, we provide a 25-Year Product Warranty

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Why Doesn’t Enverge Nexseal LE Require Mechanical Fixings?

It’s a spray-applied Polyurethane Insulation material that reaches the surface as a viscous liquid before expanding and hardening over 10-15 seconds per layer. The initial layer is usually a bonding layer, and then, depending on the final thickness, further layers are added. The strong bond to the surface is all that’s needed for Enverge Nexseal LE to remain in place for the life of the substrate. This helps to make it a long-term, durable solution that will never require topping up, replacing or removing.

What’s The Difference Between Nexseal LE And Sucraseal?

Both are certified and suitable for new and existing concrete soffits of all shapes and sizes, but Nexseal LE Closed Cell is the common choice due to its decorative appearance, vapour resistance and strong bond. Nexseal LE Closed Cell is denser and more thermally efficient than Sucraseal open cell; therefore, it will depend on the space available within the soffit assembly and the thermal targets to meet when comparing which product to choose. Sucraseal is generally cheaper and faster to install than Nexseal LE. When used as an insulation system applied directly to concrete soffits, Sucraseal will require a vapour control layer to manage moisture.

Is Enverge Spray Foam Insulation More Expensive Than Pre-Manufactured Materials?

Enverge Spray Foam Insulation is likely more cost-effective than installing pre-manufactured insulation materials in almost every circumstance. When mechanical fixings and labour time are considered, it often outstrips the competition with up to 400m2 of concrete soffit slab insulated daily. This helps reduce the project timeline and reduces disruption and downtime so that the building or structures can be returned to use rapidly. Enverge spray foam insulation has become one of the leading choices for insulating a concrete soffit when the potential periodic replacement or topping up of pre-manufactured insulation is considered.

What About A Vapour Control Layer?

Every concrete soffit insulation project is assessed on a case-by-case basis. This involves hygrothermal modelling to assess the risk of surface humidity and condensation, which can then be mitigated with our sprayable VARA Fluid intelligent membrane. Once the risks have been assessed and the building requirements considered, Enverge Nexseal LE or Sucraseal can be specified and priced accordingly. During the hygrothermal modelling, we’ll establish the thickness of the required vapour control layer and ensure that all options are communicated to the project manager.

Isn’t Enverge Spray Foam Insulation Considered Combustible?

Just about every polyurethane-based insulation material will not be classified as non-combustible. The fire rating achieved depends on the regulatory requirements and building use. The best rating that Enverge Spray Foam Insulation can achieve is a Euroclass B-s1-d0 when covered with a sprayable intumescent coating. Alternatively, when left exposed, it achieves a BS476 Part 7 Class for surface spread of flame, which can be improved to a Class 0 when coated. In some circumstances, Enverge Spray Foam Insulation is covered with a suitable lining, such as a 60-minute fire-rated plasterboard. In virtually every case, the Euroclass B-s1-d0 fire rating is more than sufficient.

Does It Come With A Warranty?

Yes. All Enverge Spray Foam Installations attract a 25-Year Product Warranty and at least a 5-Year Workmanship Warranty. Spray foam insulation is one of the most durable insulation materials available in the UK, and it won’t shrink or degrade like some other pre-manufactured insulation materials. It requires no ongoing operational or maintenance input and will remain in place as a passive insulation solution that becomes a part of the building envelope.