Damp Proofing

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Complete recommendations are given after a thorough investigation by one of our trained surveyors to determine the extent and causes of the damp problem.
Rising damp in buildings may be defined as the vertical flow of water up the wall structure or floor, the water being derived from ground water. Rising damp is normally caused by defective or inadequately installed Damp Proof Coarse. Moisture will rise in the wall up to 1.2 meter before gravitation will prevent it from rising further. This suction is in all directions. Treatment should thus always be up to 1.2 meter.
The treatment method will depend on whether the rising damp is affecting a solid floor, or is rising up a wall.

Treatment of Rising Damp in solid floors:
Several new products are now available to stop Damp rising through floor slabs, notably ECS Epoxy Floor Coating and Dry Base Vapour Membrane. Where the floor slab is contaminated or hydrostatic water pressure is excessive it may be necessary to lay CDM Industrial Membrane over the slab after which a new screed or wooden flooring can be fitted over the membrane.

Treatment of Rising Damp in walls:
Lack of Damp Proof Coarse (DPC) or poorly installed Damp Proof Coarse (DPC) is the main culprit of rising damp. Secondly, check for areas where soil or paving has been raised or installed higher than the DPC. Check for high ground levels, leaking gutters and down pipes, water leaks. Building regulations in Europe, UK and USA requires that DPC must be continuous and should be sticking out of the wall. Plastering can be done one brick higher than the DPC line.
Affected plaster is removed and replaced with a plaster applied to the specification. DPC fluid is injected into the wall at floor level to provide an impermeable barrier, preventing the damp rising up the wall.

Lateral damp is when moisture is allowed to enter the structure in a horizontal direction. Gravity then causes the downward movement of the damp into other areas. Penetrating damp can create isolated patches of dampness that increase in size after periods of heavy rain. The damp can occur at any level, unlike Rising Damp which usually rises from the ground up to 1.2 metres high. Lateral or penetrating damp is usually from a source too difficult to control and only an expert with a moisture metre detector will evaluate the difference in rising and lateral damp. Sometimes the problem may also require a plumber to pressure test the pipes to eliminate them as the problem.

Causes of Lateral Damp:
• Leaking water supplies or waste pipes
• defective brickwork
• failure of tile grouts in showers and other wet areas
• defective membrane in wet areas
• poor or unmaintained flashings
• defect in adjacent property outside the owners control
• air-conditioning or hot water system overflows can also lead to small localised patches of dampness.

All Damp proofing work carries a guarantee.