Initially, Perth homeowners notice the yellow tinge along the lower end of the internal walls. The damage to their walls would have already been ongoing for several months before the owner even noticed this sign. Rising damp Perth is a common term used in home repairs in Western Australia because of its particular location, climatic and geological factors. This is why Perth has such a high tendency to experience this particular issue that will not resolve itself on its own.
Why Perth Homes Are More Vulnerable Than Most Australians Know?
The majority of Perth is built on the Swan Coastal Plain, which has a different nature compared to clay soil in the east of Australia. Over 77% of rainfall in Perth occurs between May and September, making sure that the foundation of your house stays wet for months. On top of that, the average relative humidity during these months is 57%, while in summer the average reaches only about 39%. The moisture becomes trapped in the walls during winter and has practically nowhere to go.
Older double-brick buildings are particularly vulnerable because they are usually pre-1980s construction without any damp-proof courses in the basement. Therefore, the vast majority of older Perth housing stock has no protection against moisture getting into the building structure.
How Does Capillary Action Ruin Your Walls?
It all happens due to capillary action. Moisture in the ground gets up through the tiny openings in bricks, limestone and mortar, going up to 1.5 metres above the ground level. This moisture brings up the soluble salts present in the soil. After evaporation of moisture in your walls, the salts crystallise in your bricks and mortar causing their cracking. This is what causes cracks in your brickwork and crumbling of mortar.
White powder found on your walls is called efflorescence and is a clear sign that the process is already going on. Paint blisters and plaster bubbles on the wall are not early signs but symptoms that indicate that the problem has already been there for quite some time.
Three Most Common Causes Found in Perth Buildings
The absence of an effective Damp-proof Course (DPC) is still the most common one. Besides, another one that usually comes next is bridging: render on the outside, raised garden beds, or paving on top of the DPC line creates a connection that allows the moisture to go straight around whatever DPC there may be. Blocked wall cavity and rubbish in the building void will direct the water into the structure from unusual directions.
Historic buildings or houses built prior to 1950 in Perth can experience all three of the causes at once, and it’s the reason why precise diagnosis is much more important than quick treatment decisions.
How to Make a Problem Worse by Trying to Cosmetically Fix It?
Painting the damp-affected walls will trap the moisture inside, thus increasing the speed of masonry degradation. Putting the new render without solving the DPC problem will only raise the height of the visual problem spot, but won’t solve the problem itself. A reading of a professional moisture meter will show where the moisture has gone, and guessing will lead to incomplete treatment.
The salt-infected plaster needs to be removed completely before rendering, and not just covered up. The salts are hygroscopic, which means that they will keep absorbing the moisture from the air even after the source of the damp is sorted out. It’s one of the most guaranteed ways to have your damp “come back”.
Structural Consequences that Are Going to Add to Your Expenses
Moisture damage will weaken the masonry and mortar, and cause brickwork to move slowly. The timber components of the construction that are close to the wall with rising damp are going to be secondary victims of the situation. Unlike many other problems in the building that tend to stabilise over time, rising damp Perth doesn’t self-correct: the constant groundwater pressure on the coastal foundations in Perth is always there.
Early intervention will always be much cheaper and easier than the structural repair that takes place due to the delayed treatment. All the expenses related to the consultation with a structural engineer, brick replacement, and interior renovation that occur due to the neglected problem will be several times the initial cost.
