Is your home Watertight? Testing for moisture during your Building Inspections in Perth

High moisture levels in your home can cause significant damage over time and creates the perfect environment to attract various kinds of timber pests, most notably Termites. Well built homes don’t usually have significantly high levels of moisture retention, so when our Building Inspections Perth team does find a high moisture reading, then it’s important to investigate further to identify the root cause of the issue. High moisture not only attracts termites, but also invites wood decay and mould. Together, these are some of the most destructive issues when it comes to our homes.

How it happens and how to avoid it

Your homes first line of defence from moisture intrusion is through the water proofing barrier and or the damp proof course. These barriers are great for preventing rising damp, which can occur when moisture from under the house rises through porous materials like brick or timber and gets into the internal walls. Within the Greater Perth Region, the soil is predominantly sandy, and moisture is generally quick to dissipate making rising damp less of an issue in our area. The more common threat of moisture intrusion to our homes at ground level can be from lateral damp. Lateral damp is when the source of the moisture is higher than the waterproof barrier and or damp-proof course and is allowed to enter the building in a horizontal direction. Some examples of this include:

• Pavement or concrete around the home where leveling doesn’t direct stormwater away from the walls
• Raised garden beds up against a wall of your home
• Reticulation systems which spray water directly onto walls of your home

Another very common way moisture can enter your home is through you roof, when damaged or via faulty roof plumbing. If gutters and down pipes aren’t regularly checked and cleared out from leaf debris, the flow of stormwater can become blocked causing gutters to overflow and potentially travel across eaves entering ceiling spaces and wall cavities. Weep holes in walls allow moisture to escape in these situations but often these important vents are either non-existent or blocked by things such as raised garden beds, concrete or paving. Preventing most of these problems is really quite straight forward and much more cost effective than remediation.

At a minimum, these steps should always be in place:

• Avoid sprinklers directly hitting walls of your home
• Avoid having raised garden beds and moist mulch against the walls and footings of your home
• Regularly inspect and clean gutters and downpipes to ensure they are clear and don’t overflow
• Ensure weep holes aren’t being blocked to allow air flow

How to detect moisture in your home

Moisture usually builds up over time, remaining undetected and slowly doing damage. When the first signs of moisture show themselves within your home, it is usually detected visually. This can be from bubbling, pealing or discoloration of paint, fretting of bricks or salts and efflorescent leaching from walls.

When Total Home Inspections tests for moisture during our Building Inspections, we use Non-Destructive Moisture Meters. This gives us the ability to detect any hidden moisture related issues that aren’t yet visible to the naked eye. When moisture is detected, there is often a question mark related to whether this would be classed as a structural defect. Although the presence of any significant level of moisture is of great concern, as most homes around Perth are double brick structures, it is unlikely the moisture intrusion within a masonry wall or concrete slab would constitute a structural defect, therefore the standard clause within the REIWA pre-purchase building contract regarding sellers making good on structural defects would most likely not apply in this situation.

Over a lengthier period of time, constant moisture could start to cause significant fretting to brickwork, concrete or mortar. If this happens, it could possibly develop into a structural defect, so although it may not be a structural problem now, it is imperative to find the root cause of the defect and ensure it is remediated as soon as possible.