Sydney Based + National Delivery
Sydney Based + National Delivery
Chemical DPC injection failures are rarely caused by the product itself. Modern manufacturing processes, controlled formulation, and high-quality raw materials mean product-related failure is uncommon.
In practice, failures almost always result from installation variables, wall conditions, or incorrect specification.
This page outlines the most common failure modes encountered during chemical DPC injection work.
Any break in the injection line allows moisture to bypass the treated zone.
Shallow drilling leaves untreated pathways within the wall core.
Bridging negates the function of the damp-proof course.
Some wall types require modified methods or alternative solutions.
Salt contamination can delay drying and give the appearance of failure even when a DPC has formed.
Masonry commonly dries at a rate of 25mm (of its width) per month. Highly saturated bricks can take months to dry after injection is complete.
Uniform distribution is required to form a continuous barrier.
Previous interventions can limit penetration and coverage.
If previous injection or cream is limiting product acceptance, then the injection method should be modified to ensure that the installer can surround the target masonry with new dpc injection fluid.
Drying and evaporation must be allowed to occur after injection. (typically 5-7 days is sufficient time to wait before rendering)
Where walls are extremely wet and sufficient drying time is not available, any subsequent renders or finishes must be breathable and allow continued evaporation after application.
Successful chemical DPC injection relies on correct saturation of the masonry, not just drilling and injection.
Failure is most commonly caused by misapplication of volume, where insufficient product is introduced to fully treat the wall thickness and pore structure.
As a general guide:
These figures assume typical masonry conditions. Walls with higher porosity, voids, or elevated moisture content may require adjustment to ensure full saturation.
Understanding how water occupies the masonry—and how the injection fluid displaces or lines those pathways is critical to achieving a continuous damp-proof course.
Professional contractors should adjust dosage based on substrate acceptance to ensure full saturation of the target masonry with Silonexx and achieve the intended water-repellent performance.
Correct establishment of the Capillary Saturation Zone at every injection point is the confirmation that treatment is complete.