Pressure Washing an Older Brick Home
Pressure washing a brick house is generally a straightforward process but with older buildings some care is needed.
1. If the mortar is showing signs of damage, of wear and tear before you even begin, that needs to be repaired before pressure washing. If it is not securely sealed then water can seep through the brickwork during the wash. This ultimately affects the structural cohesiveness of the building. Once patched, the mortar has to set for at least a week before those bricks are pressure washed. At the end of the week you may want to test the repaired mortar to see how it holds up under pressure.
2. Begin the pressure wash on a low pressure setting, eg 1200 psi. Depending on the age and condition of the brickwork, the wash may need to be kept at that low pressure throughout the process. Some older bricks and mortar are softer than those used today. They can be eroded too easily by a powerful water jet. If mortar starts to fragment during the wash, this must be repaired asap afterwards or the structural consistency of the building is weakened.
3. A powerful jet spray can etch into brickwork and even into concrete in certain conditions. Bearing this in mind, keep the washer wand at a safe distance from the brick wall. On the lower pressure, this should be at least 40cm and further back if the pressure is higher. As well, use the wider fan-spray nozzle setting.
4. Wash the brickwork, complete with your choice of detergent, from the ground level gradually upwards. This prevents streak marks. Then when you do the rinse-off without detergent, work from the top level down to ensure that all dirty water is washed away. If you allow a generous ten minutes or so before the rinse off, the detergent has time to penetrate all the dirt recesses.
5. An additional safety measure that some professionals recommend is to wet the brick wall thoroughly before beginning the pressure wash. Brickwork that has been given a 'pre-soaking' seems to be more resilient during the wash.
6. Know the guidelines for using your choice of detergent. Make sure it is safe to use on your brickwork. Incorrect use of detergent may, for example, cause dirt to stick to the mortar.
7. Once all the brickwork is clean and dry, you might consider applying a sealant. This helps to protect the bricks and to keep them cleaner for longer.