Green deposits and black or red marks: identify them so you can get rid of them more effectively

Over time and when not maintained, green deposits build up and black or red streaks start appearing on your walls and roofs. It’s time to act before these marks end up taking over your entire house. Before embarking on a major cleaning operation, it is important to know how to differentiate these stains in order to treat them effectively.

Green deposits, the enemy of roofs

Rain and humidity contribute to these green deposits. These deposits become embedded in the roofs, quickly taking over them and reducing the tiles’ resistance. Lichens (white or yellowish mushrooms) and algae are also very harmful to your roofs. Over time they can lead to leaks. It is therefore important to get rid of them.

To clean effectively, you must follow two steps: brushing and then treatment with a cleaning product.

1. Brushing:
When it is a bad case with lots of growth, it is essential to scrape and brush the large deposits properly. This step allows the treatment product to really get into the substrate and enables deep-action.

2. Treatment
Once the substrate has been cleaned, use the Guard Anti-M 24. Guard Anti-M 24 is a parasitic anti-vegetation treatment that is both preventative and curative. Spray the product until it is saturated.

Leave it to work for 10 to 15 days. This time is necessary to allow it to fully eliminate parasites. The vegetation will change colour during this time, going orange, then brown and finally black when the root is attacked. Finally, the dead vegetation can be removed by brushing and rinsing or simply by allowing them to be washed away by the elements.

Red marks and black streaks, a curse for walls

Red marks are a curse for walls. These red algae grow on walls or gables that don’t get a lot of light and on wet areas near roofs and gutters. These unsightly marks become embedded in the little cracks in the walls and damage the coatings. They must be treated quickly.

Black streaks are the result of urban pollution and bad weather. The water runs down the wall, leading to pollution marks. This leaves black marks in some areas and “clean” streaks in others.

To clean the walls, use Guard Wash. Guard Wash is an active self-cleaning product for deep cleaning dirt. Start spraying the product at the bottom and work your way up. Wash’Guard is self-cleaning: no need to wash it off. However, to remove the last of the residue, you can rinse it 24h after applying it to the product.