The issue of damping is not new. In fact, it has been hailing since the Victorian era. The problem is more evident in old houses then the modern day ones. However, the problem is still relevant and the damages caused to both old and new properties are also the same. However, with changing times and technologies the methods to prevent it have evolved remarkably. According to a statistical data, there are over 4 million properties in the UK from the Edwardian and the Victorian era and it is a fairly common problem in these properties.
During the period between 1870 to 1901, the use of cavity walls began. These walls consisted of two leaves – the outer part would act as a protective layer against the weather and the inner part provided a dry surface on which decorations were done. The air between these two layers prevented the damp from passing to the inner wall by acting as a barrier to the moisture.
The damp proof course or DPC became mandatory in London in the year 1875. A DPC is a solid layer built into the wall and is placed above ground level so as to prevent the moisture from rising over the wall through capillary action. The material used in those times for DPC included – bitumen, jute, slate, and hessian. A layer of slate was the most common form of DPC then. However, over the years the decaying part of the walls fell into the cavity area and rose above the level of DPC thus bridging the air gap.
Understanding the evolving methodologies with time
Apart from that, air bricks were introduced in the late Victorian period and were used till the Edwardian period as well. These bricks were made of clay and were installed inside the walls and under the floors to allow the air to circulate and give space for ventilation.
Most of the houses in the Edwardian period used slate and bitumen whereas hessian DPC was rarely used along with engineering brickwork to provide a barrier. The damp problems usually occurred when the DPC failed, got damaged or cracked over a period of time. Later these methods gave way to the use of mastic asphalt and then lead cored bitumen till the end of 20th century.
From the latter part of the 20th century till current day various polymers have been used for DPC. Nowadays, mostly plastic damp proof courses or silicone injections are used to prevent the problem of damp. In fact, today the damp proofing solutions can be chosen according to the type of dampness. So whether it is rising damp, penetrating damp, condensation, or hydroscopic damp, the DPC can be installed accordingly.