Commercial Floor & Underfloor Spray Foam Insulation
Insulate suspended floors and underfloor voids from beneath — sealing draughts and cold-bridging in awkward, hard-to-reach spaces.
Why spray foam for suspended floors
Commercial ground floors and exposed soffits over unheated voids, plant rooms or open undercrofts lose heat steadily and invite condensation on the cold underside. Rigid boards are awkward to fit between irregular joists, beam-and-block or steel deck profiles, leaving gaps at every junction. Suspended timber and access floors are even harder to seal, so draughts track up through the floor zone into occupied space above.
Enverge closed-cell spray foam is applied to the underside of the floor structure or within the floor void, expanding into every profile and junction before curing rigid. It self-bonds to concrete, timber and steel as it sets, forming a continuous insulating and air-sealing layer with no cut-to-fit gaps. Its low water permeability also keeps the cold underside dry, removing the surface where condensation would otherwise form.
The result is a warmer, draught-free floor plate with stable surface temperatures and no damp underside. Heating loads drop, comfort improves in the space above, and the structure is protected from moisture — achieved without lifting finished floors or disrupting the occupied levels overhead.
The benefits for suspended floors
Warm Floor Plate
Seals the cold underside so heat is retained and surface temperatures stay stable in the occupied space above.
Fits Any Profile
Expands into beam-and-block, steel deck and timber joist junctions that rigid boards can never close fully.
Dry Underside
Low-permeability foam keeps the cold soffit dry, removing the surface where condensation forms over voids.
Stops Floor Draughts
Continuous air seal blocks the draughts that track up through suspended and access-floor zones.
Bonds To Structure
Self-adheres to concrete, steel and timber as it cures — no fixings, no slumping over the floor span.
No Floor Lift
Applied from below, so finished floors and occupied levels above stay undisturbed during works.
Into the tightest voids
Closed-cell foam bonds to joists and the floor underside, sealing draughts and cold-bridging even where access is restricted.
Sprayed to the floor soffit or into the void, Enverge closed-cell foam expands into joist, deck and beam-and-block profiles, then cures to a rigid layer that self-bonds to the structure. Its closed-cell matrix combines thermal resistance with low moisture permeability, raising underside surface temperatures and removing the cold, damp-prone face above unheated voids and undercrofts.
- Seals beam-and-block, steel deck and joist profiles
- 25-year manufacturer-backed warranty
- Keeps cold floor soffits dry over unheated voids
- Applied from below — no lifting finished floors
Enverge Nexseal LE — verified performance
Typical published values for Enverge Nexseal LE closed-cell foam. Full technical specification →
Specification & compliance for suspended floors
Below-ground and underfloor spaces are hostile to boards: irregular pile faces, tight crawl voids and damp-prone surfaces leave gaps everywhere. Sprayed closed-cell foam is applied at 25–100 mm directly onto the irregular surface — sheet piling, retaining walls, blockwork or floor joists — sealing cold bridging and carrying its own vapour barrier.
Because the applicator sprays in-situ, compromised voids that could never be boarded out are insulated completely, sealing draughts up into the building and bringing the below-ground envelope up to specification in a single visit.
From enquiry to warranty
Enquire
Tell us about your suspended floors & building.
Survey
Free survey of your suspended floors & condensation check.
Specify
The right system for your suspended floors.
Install
Approved applicators, minimal disruption.
Warranty
Handover pack & 25-year warranty.
Real suspended floors spray foam applications
Commercial projects
Richmond House Car Park
Underside of a car-park deck sealed and insulated in-situ.
The Box, Plymouth
Concrete soffit spray foam eliminating cold-bridging.
RBW Carpentry
Cavity-filling spray foam for an airtight commercial partition.
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.
Underfloor insulation, answered
Can you insulate the underside of a suspended floor without lifting it?
Yes. Enverge closed-cell foam is sprayed to the underside of the floor structure from the void or undercroft below, so the finished floor and occupied levels above stay undisturbed. It seals into joists, beams and deck profiles in one continuous application.
Will it stop condensation forming on a cold floor soffit over a plant room?
Closed-cell foam is low-permeability and raises the underside surface temperature, removing the cold face where condensation collects. By sealing air paths and insulating the soffit together, it keeps the structure dry over unheated voids, plant rooms and open undercrofts.
Does it work on beam-and-block and steel deck floors?
Yes. The foam expands into the irregular profiles of beam-and-block, profiled steel deck and timber joist floors, bonding as it cures. This closes the junction gaps that rigid boards leave open, giving a continuous thermal and air-tight layer across the whole soffit.
Is the cured foam strong enough for an exposed underfloor void?
Once cured, the closed-cell foam is rigid and durable, well suited to exposed soffits in voids, undercrofts and plant areas. Where the underside is publicly accessible or fire performance is required, a protective coating can be specified over the foam.
How much disruption does underfloor application cause to tenants above?
Very little — work is carried out from below in the floor void or undercroft, so occupied space overhead keeps running. We contain overspray, manage access and ventilation, and phase the work to minimise any impact on the building above.
Can you insulate a void with very restricted access?
Usually yes — spray application needs far less working room than boarding out, and the foam seals surfaces boards can't reach.
Does below-ground foam need a separate vapour barrier?
No — closed-cell foam has an integral vapour barrier, one of the reasons it's specified below ground.
What depth is used below ground?
Typically 25–100 mm depending on the target U-value and the structure — specified after survey.
Insulate your suspended floors 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