Slab and junctions
Define the treated area, slab edges, downstands and interfaces with walls. Allow for thermal bridges rather than assuming a continuous spray layer resolves every junction.
Commercial spray foam experts · Duratite Group
Concrete Soffit Spray Foam Insulation
Sprayed insulation for suitable concrete soffits, car-park decks, podiums and undercrofts. Specify the thermal layer, junctions and protective finish around the building’s requirements.
SurveyCondition and access
DesignComplete build-up
RecordInstalled specification
Start with the building
Concrete soffit insulation starts with the whole slab
An exposed slab can be a route for heat loss from the space above. Insulation applied to the underside can form part of an upgrade, but the effect depends on the complete construction: slab edges, columns, downstands and penetrations all influence performance.
Closed-cell spray foam can follow a suitable prepared soffit profile, including irregular areas that need careful cutting with board insulation. A sound substrate, planned coverage and an appropriate protective finish are essential. The survey identifies repairs and access requirements before the insulation is specified.
From the Duratite project library
Pondswick substation: concrete soffit installation
Before, during and finished photographs from the Luton project.
Read the Pondswick project and source record → · Select a photo for the full view.
Choose the scope
Details that determine the finished soffit
Services and clearance
Coordinate lighting, cable routes, pipework, drainage, signs and inspection access. Check the finished headroom, including foam thickness and any lining or coating.
Fire and durability
Agree the required finish for the location and exposure. Assess the complete tested assembly against the project’s fire strategy, impact risks and maintenance requirements.
Technical data
Enverge Nexseal LE — verified performance
Thermal conductivity λ0.027 W/m·K at 125 mm
Reaction to fireClass 1 uncoated · BS 476 Part 7
Compressive strength78 kPa · BS EN 14315-1
Water vapour resistanceμ 62 · BS EN 12086
Typical published product values. They do not establish the U-value or fire performance of the complete building assembly. Full technical specification →
Design and quotation
Specify the build-up before choosing a thickness
Provide the target U-value or performance brief, drawings of the slab and adjacent construction, and the proposed use of the space. The designer can assess thermal bridges, moisture conditions and any air or vapour control requirements. There is no single thickness that suits every soffit.
The survey should identify loose material, contamination, water ingress, cracks and concrete deterioration. Any necessary repairs and substrate preparation need to be agreed before application. Foam is insulation, not a repair for reinforcement corrosion or structural damage.
For exposed soffits, request evidence for the specified foam and protective finish as a complete system. A product reaction-to-fire result is different from the fire resistance of a floor or the compliance of a car park. Keep access to components that require inspection.
UK-wide
Where we install concrete soffits spray foam
Send your site postcode to discuss coverage, survey arrangements and access for your project.
Plan the installation
From survey to recorded handover
1. Define and survey
Send dimensions, postcode, building use and photographs. Confirm substrate condition, access and the performance required.
2. Agree the complete scope
Identify preparation, thickness, junctions, any protective finish, exclusions and work zones. Confirm programme and re-entry arrangements.
3. Check and document
Agree the handover records: specified products, coverage and thickness records, photographs, maintenance requirements and applicable warranty terms.
Proof
Commercial projects
Concrete Soffit · Plymouth
The Box, Plymouth
A documented concrete soffit application from the group’s project library.
Car Park Soffit · UK
Car Park Soffit
Underside of a car-park deck sealed and insulated in-situ.
Healthcare · Plymouth
Derriford District Centre
Spray foam insulation for a busy public-sector building.
Free survey
Get a quote for your project
Send us your building details and our technical team will specify the right system and a clear budget. No obligation.
01208 832 602Mon–Fri, 8am–5pm
info@thermofoam.co.ukWe reply within one working day
Product warranty termsDocumented, surveyor-ready installs
Questions before you book
Concrete soffit insulation questions
Where is sprayed concrete soffit insulation used?
It can be considered beneath suitable concrete slabs, undercrofts, podiums and car-park decks. The design starts with the construction above and below the slab, its condition and the intended thermal performance.
Will it eliminate every thermal bridge?
No insulation method should be assumed to remove every bridge automatically. Slab edges, columns, beams, junctions and service penetrations require their own detailing and, where needed, thermal calculations.
Does the foam repair damaged concrete or corroded reinforcement?
No. Spalling, cracks, water ingress and exposed or corroded reinforcement need assessment and appropriate repairs before insulation. Concealing a defect is not a concrete repair strategy.
Can it be used in an occupied car park?
Subject to the agreed programme and access controls. Vehicle clearance, pedestrian routes, lighting, fire alarms and other services must be considered. Work zones need isolation, ventilation and product-specific re-entry arrangements.
What fire rating can a soffit system achieve?
The required performance must be established by the project’s fire strategy. The foam, substrate, thickness, protective coating or lining and application details need supporting test or classification evidence. A generic topcoat is not a universal fire-rating upgrade.
How much does concrete soffit insulation cost?
Area, depth, headroom, access, repairs, masking around services, work phasing and protective finishes affect the quote. Send drawings where available, the site postcode and photographs of the underside and access conditions.
Insulate your concrete soffits the right way
Specialist commercial spray foam, installed UK-wide by the Duratite Group's spray foam specialists.
Book a Free Survey →or call 01208 832 602