- Proper waterproofing prevents rising damp.
- Effective drainage and DPC installation are also key to prevent rising damp.
G’day! I’m Russell McCarthy, lead building inspector at WA Building Inspections. Today, I want to discuss a crucial aspect of home construction and maintenance – rising damp. In a recent stage inspection after render application on a house in Scarborough, Perth, I encountered a great example of proper waterproofing under the render at the base of the foundation. Unfortunately, not all builders follow these best practices, despite them being required under Australian standards. Let’s dive into what rising damp is, what causes it, and how to prevent it effectively.
What is Rising Damp?
Rising damp is the upward movement of moisture through a building’s walls and floors by capillary action. This can lead to structural damage, mould growth, and other health hazards.
Rising Damp in Perth
Perth’s climate can contribute to rising damp issues in properties, making it essential for builders to implement proper waterproofing measures.
What Causes Rising Damp?
Rising damp is typically caused by:
- Lack of Waterproofing: When builders fail to apply adequate waterproofing, moisture can easily seep into the structure. You will see an example of proper waterproofing under the render in the video above and in the image below. This will prevent rising damp.
- Poor Drainage: Inefficient drainage systems around the property can lead to water accumulation at the foundation.
- Damaged Damp-Proof Course (DPC): If the DPC is damaged or not installed correctly, it can fail to prevent moisture from rising.
Rising Damp and Concrete Slabs
Even with concrete slabs, rising damp can occur if there is no proper barrier to block moisture. It’s crucial to ensure that waterproofing measures are taken at the base of the foundation such as in the photo below.
Case Study: Inspection in Scarborough, Perth
During a recent stage inspection in Scarborough, Perth, I observed how proper waterproofing can prevent rising damp effectively.
“A lot of properties have the render going directly into the sand. Now a lot of builders will tell me that’s all they need to do, but they don’t. They need to provide adequate waterproofing.”
The Right Way to Prevent Rising Damp
In this inspection, the builder had done the right thing by applying waterproofing under the render at the base of the foundation.
“Okay, so this build is done correctly but we get this all the time where a builder will refuse to protect the exterior render from rising damp. It is a requirement in the Australian standards.”
This highlights the importance of following Australian standards to prevent rising damp.
Why Waterproofing is Essential
Waterproofing is crucial to prevent rising damp because it:
- Blocks Moisture: Prevents water from seeping into the walls and foundation.
- Protects Structural Integrity: Helps maintain the strength and durability of the building.
- Prevents Mould Growth: Reduces the risk of mould and other health hazards. Our mould inspections regularly report that rising damp is the cause of a lot of mould problems in perth.
Australian Standards for Waterproofing
Under Australian standards, it is mandatory for builders to apply adequate waterproofing to protect against rising damp. In my 20 years inspecting new residential constructions, I would estimate that only around 20% of builders actually do this!
“Proof that there still are builders among us who can have the right thing done.”
This standard ensures that properties are built to withstand moisture-related issues.
Common Mistakes Builders Make
Many builders make the mistake of not applying waterproofing, believing that render alone is sufficient. This defect is something we commonly find in our waterproofing inspections.
- Render into Sand: Applying render directly into the sand without waterproofing.
- Ignoring Standards: Failing to comply with Australian waterproofing standards.
- Poor Installation: Incorrect application of waterproofing materials.
How to Prevent Rising Damp
Here are some best practices to prevent rising damp:
- Proper Waterproofing: Always apply a waterproof barrier at the base of the foundation.
- Install a Damp-Proof Course (DPC): Ensure that a DPC is correctly installed.
- Improve Drainage: Implement efficient drainage systems around the property.
FAQs about Rising Damp
1. What is rising damp?
Rising damp is the upward movement of moisture through walls and floors by capillary action.
2. What causes rising damp?
Rising damp is caused by a lack of waterproofing, poor drainage, and damaged or incorrectly installed damp-proof courses.
3. How can rising damp be prevented in Perth?
Proper waterproofing, installing a damp-proof course, and improving drainage can prevent rising damp.
4. What are the Australian standards for waterproofing?
Australian standards require builders to apply adequate waterproofing to protect against rising damp.
5. How does rising damp affect concrete slabs?
Without a proper moisture barrier, even concrete slabs can be susceptible to rising damp.
My Final Words
Preventing rising damp is essential (and easy to do) for maintaining the structural integrity and health of your home. As highlighted by the building inspection in Scarborough, Perth, following Australian standards and applying proper waterproofing measures can make all the difference. Always ensure that your builder adheres to these best practices to avoid the costly and damaging effects of rising damp.
For professional building inspections and advice on rising damp, feel free to reach out to us at WA Building Inspections. We service Perth-wide and have branches:
WA Building Inspections Perth,