It is important to plan your weather proofing before you commence construction. In weather proofing a wall it is necessary to consider both the mortar joints and the blocks separately.
For a wall to be fully weather proof it is important for a waterproofing compound such as Lanco 322 to be added to every mix of mortar, using the recommended ratios as supplied by the manufacture. Failure to ensure that the bricklayers adhere strictly to this can result in joints that are not adequately weather proofed.
One point to note is that the waterproofing compound must be added directly to the mix, and not mixed into the bricklayers water drum as this will lead to dilution of the waterproofer as more water is added to replace the water as it is used.
All of Bathurst Concrete Products coloured blocks have a waterproofing compound added as standard. This compound makes the blocks quite water resistant but we still recommend a further treatment with an approved sealer after the wall is constructed to ensure proper weather proofing.
For Colonial or Coloured blocks Bathurst Concrete recommends 2 coats of BC 800 applied according to the manufacturers recommendations.
For plain grey blocks several coats of exterior house paint to the manufacturers specifications will be sufficient to weather proof the blocks.