- Identify if there are pipes or electrical cables that you might drill into.
- Reason: you are drilling into the unknown, a leaking pipe and or sitting with no electricity will not make you very happy.
- Determine how damp the walls are, this will determine the spacing between holes
- Reason – Severe damp requires holes to be drilled closer to each other. Drill holes at 75mm intervals for severe damp.
Where to drill
Locate slab level. Drill 12mm dia holes 50mm above the slab level – drill angle must be horizontal and drilled into the wall in a horizontal line.
- Use a SDS drill and use an industrial drill, small drills will not make it
- Use a high tenstile concrete drill
- 12mm dia
- 230mm long
- Drilled holes spacing is 75mm (very damp walls) or 100mm for damp walls.
- Important!!! Care must be taken about the quality and porosity (absorption ability) of the brick. Reduce the drilling intervals to 75mm if the bricks are very porous or weak.
- Remove the dust from the holes.
- Reason – Dust takes up volume, you want to create enough volume for the cream to fill and then to spread and create a chemical DPC.
How deep do we drill: –
- The holes must be drilled to a depth of 20mm less than the wall width.
- Reason: We don’t want to drill through the wall and waste DPC cream.
- You are provided with an 8mm pipe that need to be attached to the nozzle. The pipe must be fed into the hole right to the back of the hole.
- Inject the DPC Cream slowly into each hole using a 1lt caulking gun.
- Insert the nozzle to the rear of the hole and slowly withdraw the nozzle as the cream fills the hole. A 1lt cartridge will treat approximately 4.0 meters of double brick wall, depending on the porosity of the wall.
- Fill the hole to capacity, there must be no air bubbles inside the drilled hole.
- Holes must be capped with PlugMix or mortar or a Polyfila plug.
- Reason: if the holes are not plugged then the DPC cream will spill out from the filled holes.
How long does it take before the DPC Cream spreads
The DPC cream spreads within 4 to 6 weeks to form an impervious barrier.
Warning!!! Some walls are cavity walls or has a double leaves. Some mortar joints are also hollow. Ensure that you do not inject the DPC cream into cavities, this is wastage, only the hole that was drilled into solid brick or mortar must be filled with DPC cream.