Corrugated Roof Spray Foam Insulation

Insulation that follows the sheet profile

Corrugated and box-profile sheets need careful detailing around ridges, troughs, fixings and junctions. Spray-applied insulation can follow a suitable underside profile, reducing the need to cut individual boards around each contour. The substrate must be suitable for adhesion and in a condition that can accept the specified system.

Metal, fibre-cement and asbestos-cement sheets need different assessments. Establish the material, condition and existing coatings before choosing preparation methods. Suspected asbestos requires appropriate survey information and a planned method of work.

Choose the inside or the outside of the roof

Underside insulation

Applied from inside, closed-cell insulation is specified around the building’s heat-loss and condensation requirements. Rooflights, ventilation paths, services and inspection needs must be allowed for. This route does not replace the weatherproof covering above.

External roofing foam

Applied from above, a roofing-grade foam forms part of a complete external system with the specified compatible membrane or coating. Roof edges, drainage and penetrations need detailing. See external spray foam roofing and interior and exterior encapsulation.

Check why the roof is wet before insulating

Drips can come from condensation, failed fixings, sheet damage or laps admitting rainwater. The diagnosis changes the work required. Insulation can improve the internal surface conditions, but humidity, ventilation and junctions still influence condensation risk.

Loose sheets, corrosion, wet substrates and failing coatings need investigation. Spray foam is not a substitute for structural repair or a guarantee against hidden deterioration. The survey should also consider how future roof inspection and maintenance will be carried out.

What to agree before installation

Ask the quotation to identify the product, installed depth, preparation, coverage boundaries, excluded roof areas, access method and any required protective finish. Thermal targets need a calculation for the complete roof construction; the same foam thickness will not deliver the same result on every building.

Fire performance must be considered for the installed assembly and the building’s use. Where asbestos is present, the work method and ongoing asbestos records form part of the project. For occupied industrial premises, agree work-zone separation, ventilation and re-entry with the installer.

For the building around the roof, explore warehouse insulation or agricultural building insulation.

Send the information that shapes the price

Include the site postcode, approximate roof area and height, sheet material, photographs taken from a safe position, and the problem you want to solve. Tell us about leaks, existing insulation, access restrictions and whether the premises are occupied. A survey can then establish the scope, programme and suitable system.