Can I waterproof under and over screed?
Essential guidance on waterproofing applications with screed layers. Outlining proper installation methods and best practices.
The Optimal Solution: Under & Over Screed dual-membrane System
Double Protection System
The Under Over™ puddle flange dual-membrane system provides the ultimate waterproofing solution. In the event of a over-screed waterproofing membrane failure, the under-screed waterproofing membrane still protects your bathroom or balcony from leaking.
Advanced Drainage System
The Under Over™ puddle flange dual-membrane system allows drainage between the waterproofing membranes if water penetrates into the screed. This prevents water entrapment and provides continuous protection even if the over screed waterproofing membrane is compromised.
Installation Benefits
- Redundant protection - if the over screed waterproofing membrane fails, the below screed waterproofing membrane maintains protection
- Drainage pathway between membranes prevents water accumulation
- Enhanced long-term reliability and peace of mind
- Suitable for high-risk areas like bathrooms and balconies
- Complies with and exceeds Australian Standards requirements
Under Screed Waterproofing
Under Screed Waterproofing Protection Layer
The under-screed waterproofing membrane forms the foundation of your waterproofing system, applied directly to the substrate before laying the screed.
Installation Process
- Clean and prepare the substrate thoroughly
- Apply primer if required
- Install under-screed waterproof membrane
- Allow proper curing time
- Lay screed over the membrane
Over Screed Waterproofing
Over Screed Waterproofing Protection Layer
When combined with under-screed waterproofing, the over-screed waterproofing membrane provides an additional barrier and is the recommended approach for maximum protection.
Enhanced System Benefits
As part of the dual-membrane system, the over-screed waterproofing membrane layer works in conjunction with the under-screed waterproofing membrane to provide unparalleled waterproofing performance and built-in redundancy.
Australian Standards & NCC Compliance
The Australian Standards serve as a guideline that becomes mandatory when referenced by the National Construction Code (NCC) regarding underscreed and overscreed waterproofing. The NCC specifies that either underscreed or overscreed waterproofing must be implemented; however, it does not prohibit the use of both methods. Therefore, employing both techniques can provide enhanced protection and ensure superior waterproofing performance.
Best Practices
Do's
- Always waterproof under screed when possible
- Use appropriate membrane thickness
- Ensure proper substrate preparation
- Allow adequate curing time
- Follow manufacturer's guidelines
Dont's
- Don't rely solely on over-screed waterproofing
- Don't skip primer when required
- Don't rush the installation process
- Don't ignore substrate conditions
- Don't compromise on material quality
Need Professional Advice?
For more information or contact your local stockist to find a licenced installer.