The most common rising dampness in this building is due to the overflow pipe drip outside. The overflow drip saturates the wall completely and wet. The wall can penetrate inside the cavity and that can cause dampness in this building.
Another problem overflow pipe may be drip inside the cavity wall and the water can drip inside the cavity, splash the foundation and the inner and outer leaf of the cavity will penetrate the dam in the building.
The Ground Level below the DPC penetrates the wall and foundation as shown in the index below and causes of the damp.
Solution:
The water overflow pipe needs to be replaced and extended to the main gully, the mouse bills need to be clear and closed properly, and the ground level should be below the DPC up to 150mm.
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