Traditionally, rigid boards or polybeads were used to insulate, however, these systems do not offer the airtightness that is achieved with foam nor do they compare with the insulating qualities of spray foam.
The application of closed cell foam, because of its high density, results in an airtight, waterproof barrier and achieves the high u-value requirements all in one application.
It also restores the structural stability of older builds where mortar, brick or stone have degraded or where the conventional wall ties have corroded. By creating this water tight membrane, it has excellent resistance to driving wind and rain ultimately reducing air leakage from the external environment to to zero.
It is quick and easy to apply with a minimal amount of disturbance and mess and can usually be completed within a day.
Basically, holes are drilled in the external wall at certain intervals. The spray foam is then introduced into these holes creating the airtight seal. This process is continued horizontally and upwards of the walls until the entire structure is insulated.