- Blocks stacked on site and been used in the building should be kept as dry as possible.
- Do not rake out the joints when pointing, use a half round tool so that the mortar remains on the front edges of the block. This method is better for waterproofing.
- Any mortar that spills onto the face of the block, allow to partially dry before trying to remove, use a scraper and nylon brush with mortar-cleaning agent from a bucket.
- Start off with a weak solution and increase the strength until the ideal dilution is found.
- Do not use a hose pipe on the block work, a high pressure water cleaner may be used as a final clean provided the correct nozzle is used and there is minimal water penetration into the block.
- After the block work has been cleaned and allowed to dry waterproof by using water repellant, a siloxane product or similar.
More guidance on building with concrete blocks can be found in the masonry manual obtainable from the concrete manufactures association or on their website: www.cma.org.za