Universal Basement Waterproofing were required to install a basement waterproofing system throughout the entirety of the basement level for a pub located on Tyres Street, London. The basement had become susceptible to rising damp, and laterally penetrating dampness due to high external ground levels surrounding the basement.

The waterproofing system was required in order to prevent further damage to the property from the ingress of damp. The basement space was an area in use by the pub and therefore needed a relatively quick and absolutely reliable waterproofing system installed.

Several key areas of damp were found in the basement, all showing results that suggested rising damp in some areas, and in others penetrating damp. In one area of the basement, an interior wall had been constructed in front of an exterior structural wall which was damp. This damp wall, then affected the interior wall with transferred dampness.

Methodology

Structures below ground are often susceptible to the ingress of damp, due to the nature of their construction. The basement located on Tyres Street had begun to show signs of damage from both rising and laterally penetrating damp.

Rising damp is the action of moisture movement upwards through permeable building materials, via capillary action. This becomes problematic to living conditions when this moisture begins to penetrate vulnerable building finishes such as masonry and plaster. The problem of penetrating damp is quite often caused by defects in the construction of a building, like in the case of the property on Tyres Street, poor external wall construction below ground level has led to the ingress of damp into the basement.

Once the areas for waterproofing were prepared and ready, walls exposed to bare masonry and any timber such as skirting boards and door liners removed, the first step of waterproofing could then be undertaken. This was to install a horizontal Thixotropic cream damp course to the walls. This series of works would include vertical injections to abutments or split-level structures. The Thixotropic cream is considered to have a very high concentration of water miscible active ingredients, this means that the cream itself reacts with any moisture within the wall and actively prevents the effects of rising damp. After the Thixotropic cream damp proof course had been installed, our technicians began to apply the Sika waterproofing render. In the areas where the render was first applied, no structural waterproofing was required, in this instance, the Sika waterproofing render was installed in two coats to a smooth finish. This was then finished with a high quality plaster finish incorporating salt inhibiting elements in order for the prevention of hygroscopic salts to course damage to the plaster in the future.

In order to finish successfully installing our waterproofing system, our technicians also had to waterproof the remaining structurally important areas of the basement. This included the section of wall, previously mentioned, where our technicians were required to demolish a false wall, built in front of a damp earth retaining wall. In order to be successful in our waterproofing of these important segments of the structure, it was required that we adjust our application of the previously installed Sika render. To achieve this our technicians installed three coats of Sika-1 structural waterproofing render. The additional coat of render is what is referred to as a “splatter” or “cast” coat. This is the process of actively casting the render onto the wall, this creates a much-increased bond between the render and the substrate of the wall. This then effectively improves the overall strength and resilience of the waterproofing render system to excessive damp ingress.

Case Study Results

The finished project at Tyres Street provided our client with a hugely improved basement space. The existing basement had become under threat from the continued effects of both rising and penetrating damp, with interior finishes and fixtures being affected. The successfully installed waterproofing system ensures the quality and integrity of the below ground structure for years to come, and the client can continue to use this space safely and with the knowledge that the property is protected from the effects of water and damp damage.