Rising Damp

Rising damp can occur for a number of reasons, including failure of an existing original damp proof course perhaps due to bridging of the damp proof course where external or internal floor levels may have been raised, or where walls are of a cavity construction, blockages or a obstruction or debris in the cavities may bridge any damp proof course. More often than not, regarding the majority of older buildings predating 1890 a complete absence or lack of an original insitu damp proof course is likely.

Walls constructed of brickwork, or stone and mortar are porous, this will allow dampness from the ground to rise via capillary action. Moisture rising from the ground will inevitably collect ground mineral salts, including chlorides and nitrates. During the drying process or when moisture evaporates from the wall structure, these mineral salts maybe deposited to the surface, the salts are what are known as hygroscopic, and therefore will attract or absorb moisture from the atmosphere leading to wall dampness in a condition of high relative humidity which may lead to deterioration of the decorations and breakdown of internal plasters, or indeed may encourage wood rotting fungi or decay.

A typical specification appertaining to the elimination of rising damp, is to remove the damp affected plasters to a minimum height of one metre above ground level, or to at least a height of 300mm – 400mm above the highest area of damp affected plaster. A chemically injected damp proof course system of one type or another, may then be installed in accordance with British Standard BS.6576 (2005) followed by replastering using a suitable renovating plaster system to strict specifications. It maybe necessary to consider, on occasion, to incorporate within the damp proofing programme a suitable compatible vertical damp proof membrane. Our specialist trained qualified surveyor will advise on this in more detail subsequent to his inspection, when a full written report recommendations and specifications with regards to actions necessary to overcome rising damp, if found to be present, will be submitted. To arrange for an initial free of charge without obligation survey to this regard, we will follow on with our contact information on our contact page on this web site.

Injection DPC Tri-Gel

Structural Waterproofing/Lateral Moisture Penetrating Dampness

In many properties particularly in the Brighton and Hove area and indeed in the south coast, there are unused lower ground floor/basement or cellar areas, where externally high ground levels to the perimeter, typically to the main front elevation will encourage dampness to penetrate laterally. When considering the very high cost of property in this region, and with living space at a premium, inevitably it would be considered cost effective to successfully damp proof the basement or cellar area, to form part of the living accommodation, and this would involve internal remedial structural water proofing and associated damp proofing works and replastering. During any inspection arranged, our surveyor will advise to this regard and specify one or a number of different types of systems which are available depending on circumstances, to successfully eliminate dampness, including considering the most widely used systems involving either a cementatious type chemical vertical membrane or ‘tanking’ application, or perhaps a cavity drain membrane system, which is becoming more popular, involving less initial destruction and preparation works.

The cementatious systems normally require plasters and renders internally to be removed back to the original masonry, and it may also be necessary at the same time to consider incorporating within the cementatious system (or the cavity drain membrane system) a chemically injected damp proof course depending on the external ground levels or adjoining property levels which will be taken into consideration by our surveyor during his inspection.

Generally cementatious systems such as Vandex BB.75 or Triton TT.55 waterproof slurry, require a render coat of washed sand and cement to be applied to the prepared clean brick or stone masonry with the cementatious membrane applied to the surface of the new render as per the manufacturers recommendations in a minimum of two coats (green on green) with suitable overlap detailing between the vertical membrane of the walls with any proposed horizontal membrane depending on floor construction or proposals.

The cavity drain membrane systems, such as Tritons Isola Platon System, provides an alternative to conventional cementatious tanking systems. Cementatious systems work by holding the water back within the wall structure, the cavity drain membrane system works on the principal of allowing water to continue to penetrate the structure, but controlling the dampness in the air gap and diverting it to a suitable drainage point. Depending on circumstances this could involve the installation of a suitable sump pump which may incorporate a backup and failure warning system. This system does not allow pressure to build up against the internal construction, and the air gap behind the membrane allows the structure to breath ‘and to some extent dry’. Membranes are of plastic, type, and are fixed to the masonry using special damp proof seal plugs, sealing tape and rope, with overlap detailing at junctions, which involves minimal preparation required to the substrat. It is often a requirement when installing cavity drain membrane systems however as mentioned earlier, to incorporate within the programme the installation of a drainage sump pump system which may include a back up pump and failure warning alarm.

Typical unused space.

Installing a cavity drain membrane system.

Installation of fixing plugs to plation.

A stunning basement conversion.

Condensation

The incidents of condensation affecting properties in the UK has risen considerably over the last 10 – 20 years or so, the consensus of opinion being that although as a nation we have become more energy conscious, this has resulted in a lack of natural ventilation within our properties, encouraging condensation. Condensation in general terms may be overcome or at least reduced by the introduction of a balanced system of heating and ventilation. Domestic dehumidifiers are a modern answer in helping to deal with condensation problems, the most renowned manufacturer of domestic dehumidifiers is EBAC, and our company stocks the EBAC range of domestic dehumidifiers, which may be purchased direct from Bensleys with arrangements for delivery at no additional cost. Should you require information to this regard, please do not hesitate to email or contact our office for a suitable quote.

Condensation control units may be fitted, in some circumstances, in either a loft or suitable internal position, which may be a more long term consideration.