Slow pour spray foam insulation is used to insulate a cavity with polyurethane – this is injection applied through 12mm holes generally created through the pointing where they are easily filled and barely noticeable.

Given that cavity wall insulation is by its a nature a “blind” exercise, the best method to follow is mathematical, first the depth of the cavity must be found, and in already understanding the expansion and flow rate of the material we then have a clear indication of the length of time pumping is required to achieve a complete slow pour spray foam insulation fill. A squared drill pattern is required to ensure the foam when injected expands to meet itself at regular intervals. After the event, all that is required is to fill the drill holes with a matching mortar or exterior filling compound and clean any excess materials on the wall surface.