The gap is formed by shrinkage at the outer bourder between the brick wall and the concrete path. When water hits the wall (in a storm) it is channeled down the wall under concrete path and to the foundations. The brickwork under the path has many holes in it which allow the water to penetrate to sub floor area and is collecting in a dam action. The sealer must be flexible as the gap expands dramatically over dry summer and shrinks to 10mm in wettest winter. Thanks in advance.
06 July 2013, 12:43 PM
Selleys Proseries Flexiseal will be best for sealing these cracks. It is a highly flexible polyurethane construction sealant, commonly used in construction and expansion joints. We recommend using a polyethylene foam backing rod under the sealant to avoid three-sided adhesion. This allows the sealant to flex within the joint more easily.