My house is a detached house with brick cavity walls, built in 1960s. It has a suspended timber ground floor. Previous owners had block paving installed around the outside, and this has decreased the ground level to DPC gap to about 100 mm. It has also covered all the underfloor airbricks, which in neighbours' houses are in the second course below the DPC. Does anyone know of a practical way of establishing adequate under floor ventilation that does not involve lifting and relaying the block paving?