Melbourne Property Restorations

Rising Damp Specialists
Home l About Us l Rising Damp l Ventilation l Mould I Contact Us











Melbourne Property Restorations are a Melbourne based company servicing all suburbs. Our damp-proofing service extends to country Victoria, with a regular service including Bendigo, Ballarat, Geelong, Seymour, Benalla, Wangaratta, Albury/Wodonga.

All trades are completed to the highest standard, including 30 year warranty on damp-proofing. We are fully insured.


Rising Damp


Rising Damp(Salt Damp)

Rising Damp(Salt Damp) is not the most common form of dampness encountered in buildings: this is left to condensation. However a high proprtion of older buildings are affected by rising damp to some degree or another.

Rising Damp in buildings occurs when water from the the ground rises up through the bricks and mortar of a building by a process loosely termed "capilliarity." In simple terms, the water rises up the wall of a building in the same way that oil rises up through the wick of a lamp.

The height to which the water rises depends on several factors including por structure of the brick and mortar and the rate of evaporation.


Ground water contains soluble salts, the most significant of which are chlorides, nitrates and sulphates. When rising damp occurs, these pass with the water up the wall and are left behind when the water evaporates. Over many years of active dampness large quantities of these salts accumulate within the masonry and decorative surface, most becoming concentrated in a general 'slat band' towards the maximum height of rise. Both chlorides and nitrates are usually hygroscopic,(ie they can absorb from the sorrounding environment) and, in general the greater the amount of saltsthe greater the absorption of moisture -especially under humid conditions. Thus, eventhough rising dampness may have been controlled by the insertion of a remedial damp-course the salts alone can cause the wall and any contaminated decorations to remain damp. It is for this reason that specialist replastering is such an important aspect of rising damp treatment.


Treatment of rising damp(known as "damp-proofing" or "dampcoursing") typically involves the installation of a chemical DPC followed by replastering using a salt retardent render. However, with the introduction of damproof creams, the process has now been simplified. The cream is injected into the holes in the masonry without the need for an injection pump.

Choosing a waterbased cream rather than the older paraffin based system will allow for a cleaner and quicker installation. A good quality cream like Dryzone(30 year warranty) are odourless, non-toxic and contain no hydrocarbon solvents. Waterbased creams are completely safe with no volatile chemicals, allergy free, non-caustic and non flammable.


Mould is a fungus that can grow on food or damp building materials. The mould prefers to grow in damp, dark and unventilatd areas. Appearing as a stain it comes in a variety of colours. Some types of mould may not be visible but but can have a musty smell or odour. Mould reproduces by releasing small pores into the air. Inadequate ventilation will allow a build up of mould and in turn ciontribute to poor air qualit.


Mould will grow in most parts of the house or building where the conditions are ideal, bathrooms, kitchens and laundries are known wet areas. Mould will be found on bedroom walls and around windows and cupboards.


A number of factors will cause mould growth, poor ventilation, moisture, high humidity, condensation, temperature, lack of sunlight, poor insulation.


Mould spores are present outdoors and are small enough to breathe them in, this is known to affect some people with asthma or allergies. Where mould is present indoors there is a higher concentrationof spores, this is known to trigger health problems. People who suffer from asthmas or allergies are prone. Mould spores can cause nasal congestion, respiratory infections, sneewing, coughing, skin and eye irritation and headaches.


Cleaning mould can have an adverse affect on your health, if in doubt seek a professional cleaning contractor. If you are going to clean affected areas it is essential that protective clothing and a mask are worn. It is imoprtant to kill the spores and wash down. Under no circumstances should mould be dry brushed as this will release spors throughout the property.

Using a natural cleaning product like vinegar and a small amount of water will kill spores and allow affective wash down. Clove oil is another natural product but must be diluted with water. Bleach will notkill spors and is not recommended.


Cleaning mould will not solve the problem. Given the correct conditions mould will keep re-appearring. It isimperative to remedy the problem in the building. This requires correct diagnosis and treatment.


A major cause of mould build up is the result of poor or idadequate subfloor ventilation. Once relative humidity levels within the building exceed 60%, mould will gdevelop. A damp subfloor will also provide ideal conditions for termites and timber decay. It is essential to have adequate airflow. This requires sufficient air entering and exiting the subfloor(crossflow ventilation). Increased crossflow will promote drying and a healthy environment.

Subfloor vents require inspection and cleaning if required. Additional vents may be installed if adequate crossflow is possible. Existing passive vents can be replaced with more efficient designs. This will allow greater inflow of fresh air and outflow of stale air. Where there appears to be sufficient vents but crossflow ventilation is not being achieved. Forced ventilation in most cases will remedy this problem.

Low voltage ventilation fans 12V can prove affective in small areas and where access to subfloor is restricted. The benefits of this ventilation system are relatively low installation costs, low noise and running costs. As this system is low voltage it is unable to remove larrge volumes of air so it is restricted in it's application.

Alternatively an inline centrifugal subfloor ventilation fan which operates on 240V can function under more testing conditions. With the installation of ducts this system is a more targeted approach to creating affective crossflow. The downside higher installation costs, higher noise levels and running costs(similar power usage to a 75W lightglobe). The fan is set on a timer and operates only during daylight hours.

If the subfloor is being used for storage or there is a build up of building debris this may be restricting airflow. Heating systems which use large ducts should be avoided. In some cases ducted heating can be replaced with a hydronic system. Removing excess soil from subfloor should be avoided as this can create an area for water to pool.

In addition to subfloor ventilation it is important to ensure that water levels are kept to a minimum. Finding the source of any moisture problems and fixing any leaks is essential. Leaking downpipes and gutters, blocked stormwater drains are common sources and can significantly increase moisture levels subfloor. Installing a perforated plastic pipe(aggie) will not only remove excess surface waterbut can help reduce ground water levels. The building may have a rising damp issue, this requires expert diagnosis. Rising damp can be a moisture source for mould to develop.

Lastly the building may be located in an area that is prone to flooding. A prvention pan that restricts the ingress of water should be considered. The ability to open and close vents and doorways when flooding commences. Brickwork, stonework, render can be coated with a water repllant that will prevent saturation of the building fabric. A good quality repellant(Stormdry) will last at least 20-25 years. All defective mortar should be reinstated.
Home l About Us l Services l Rising Damp I Ventilation I Sub-floor Ventilation I Mould Cleaning I Damp House I Request Quote l Contact Us | Links