Quick answers
The flat above the pilotis has a cold floor. Can it be insulated?
Yes, from below: the pilotis ceiling is the floor of the flat. It can be sprayed with polyurethane foam in one continuous layer, without touching anything inside the home.
The pilotis is an open space, exposed to the air all year round. Its ceiling is also the floor of the flat above. Without insulation, the winter cold passes straight into the floor of the home, and so does the summer heat.
The good news is that the work is done entirely from below, in the pilotis, without lifting floors or bringing rubble into the flat. In this job the light fitting was taken down first and its wiring wrapped, the walls, openings, air conditioner and floor were covered in plastic sheeting, and polyurethane foam was sprayed over the whole ceiling in one layer with no joints. The light points were left clear so the fittings could go back.
The same material went onto a room ceiling in another job, where the foam was painted white after spraying to protect it and brighten the room. The surface keeps a slight, textured finish rather than being smooth like plaster.
Because the pilotis is a shared space, it's a good idea to let the building manager and the other owners know beforehand. One practical detail too: spraying leaves fine droplets in the air, so cars and anything else in the pilotis have to be moved or covered.
Jobs that show it
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
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