The diagram shown depicts a series of example drilling patterns for external walls when using Tri-Gel and high-pressure siliconate. Tri-Gel is preferred for drilling into mortar bed whereas high-pressure siliconate is better for drilling into brick. However, these may vary according to the pattern used in the construction of the wall. The depth of drilling will also vary when solid or cavity walls are a feature of the build.
Where cavity wall construction has been used in the building process, the chemical injection course is instead taken through the outer skin and continued on through the inner wall of the pair. This diagram is also based on high-pressure siliconate injection.
Note: Garratt’s currently use Triton Tri-Gel cream for the chemical DPC. With this application, the injection is carried out into the mortar as opposed to the brick. Not only does this provide a good practical solution, but it also looks much better from a cosmetic point of view, too.
Where there are multiple, stepped levels adjoining the property, other drilling patterns will be employed. The diagram to the left shows one method that may be deployed in this instance.
Abutted walls are a common feature of modifications and home improvement projects such as garages, conservatories and porches. Constructions of this nature are a frequent source of rising damp, so in cases like these, the treatment also requires the injection of a chemical damp proof course. This will typically use a pattern as shown in the diagram on the right.