Quick answers
Can sprayed polyurethane foam be used on the exterior walls of a new build before plastering, or on an interior ceiling?
Yes. On bare exterior walls of a building under construction, sprayed foam forms a seamless thermal blanket before rendering, while on interior ceilings or pilotis soffits it is sprayed from below and can be painted white.
Sprayed polyurethane foam is not only for flat roofs. Because it bonds directly to concrete and brickwork and expands to fill every gap, it is also used on vertical walls and on the underside of ceilings.
On this building under construction, the bare exterior walls were sprayed from scaffolding with a continuous layer of polyurethane foam, covering brickwork, columns and beams in one seamless blanket without thermal bridges before the render goes on.
Similarly, when a room beneath a cold slab needs insulation from the inside, the walls, floor and light fittings are wrapped in plastic sheeting, the ceiling is sprayed with polyurethane foam, and the cured surface is painted white.
Jobs that show it
Spray Polyurethane Foam on the Walls of a New Build
The bare outside walls of a house under construction were sprayed with polyurethane foam in one continuous insulating layer, with render going on top afterwards.
See the job step by step
Spray Polyurethane Foam on a Ceiling, Painted White
The room was wrapped in plastic sheeting, the ceiling was sprayed with polyurethane foam, and it was then painted white.
See the job step by step
Pilotis Ceiling Insulated with Spray Polyurethane Foam
The ceiling of the pilotis, the open ground floor under the building, was sprayed from below with polyurethane foam to insulate the floor of the flat above.
See the job step by step