Expanding foam is a can of liquid that quickly expands and hardens once sprayed. Once dried, it can be trimmed, sanded and painted. It is ideal for sealing gaps around pipes and wires; essential for energy efficiency, to keep your home warm.
Using a large, dry paint brush, sweep away any dust or loose particles in and around the area. When the area is clean, spray it lightly with water. Expanding foam needs moisture to cure, so this will help the foam cure evenly.
Before applying the expanding foam, read the manufacturer’s instructions. Expanding foam is a skin irritant so it is essential to wear protective gloves during its use. The expanding foam is applied using a gun or nozzle that comes with the product. Attach the nozzle and shake the can thoroughly. Hold the can upside down, insert the nozzle into the area to be filled, and apply the foam carefully bearing in mind it will more than double in size once applied.
Immediately after applying the foam, mist it with water. If you apply more than one layer of foam, spray water between each layer to help the foam adhere. Leave the foam to cure fully, which usually takes one hour depending on the manufacturer’s instructions.
When the foam is fully cured, carefully use a hacksaw to cut off any excess.
Use sandpaper to sand the foam and give a smooth finish. The expanding foam can now be plastered or painted over.