This is a chemical free damp proofing system, which utilises the principle of Electro-Osmosis. Electric-Osmosis occurs when an electrical potential is applied across a damp porous material, which causes a force to be exerted on the water, which then moves towards the cathode (earth).
The system involves inserting platinum coated wire nodes into the wall at regular intervals. These anodes (which are joined together by plain titanium wire) are placed around the building in a ring main like configuration. One end is connected to a low voltage power supply and the circuit is completed at the other end by an earthing rod (cathode) driven into the ground below that of the anodes and at a distance of at least 2 metres away from the nearest anode. The completed and operational system then provides the electrical potential, which stops rising damp and allows the wall to dry out.
It is common in a wall suffering from rising damp for salt water to concentrate in the wall. As the wall dries out following insertion of a damp proof course these salts may be deposited on or near the surface and can give rise to efflorescence. If the salts are hygroscopic, damp patches may also develop when the ambient humidity is high unless steps are taken to ameliorate the problems. Failure to do so may allow or give rise to other dampness problems of a more persistent nature. It is essential, therefore, that a suitable replastering schedule is adopted following the insertion of a damp proof course. Replastering should be carried out as long as possible after the insertion of the remedial damp proof course. Ideally the new plaster should be applied to dry walls but in any case a drying period of at least 14 days should be allowed between installation and replastering wherever possible
A specially formulated dry mix of cement, quartz and reactive chemicals which when mixed with water, and inserted as described will create a chemical damp-proof course. The product is particularly useful in random stone wall constructions. The chemicals releasereact and form a crystalline growth which penetrates and blocks the capillaries, pores and fine cracks in mortar joints.
Silicone Injected Damp Proof Courses.
This system uses a water based fluid, which is injected, into the mortar joints to form a continuous barrier to the passage of moisture rising from the ground. After injection the fluid reacts with carbon dioxide to form a water repellent silicone resin network within the capillaries of the substrate. This silicone resin network is permeable to water vapour which means that the walls can breathe and dry out naturally.
Studded membrane systems are used to achieve a dry internal surface in situations where dampness is penetrating laterally. Such instances occur where external ground level is high. The most effective solution is to lower the ground level. However in many instances this is not practical. The alternative therefore is to apply a membrane on the internal wall surface.
The membranes can be self supporting or may require timber framing within a secondary wall depending on water pressures and construction. They provide a water vapour barrier and create a healthy internal environment.