That can be a rewarding job, but take the dangers seriously!
What is "dirt"?
- Organic: fungi, moss and alga
- Inorganic: lime and iron
- Residual waste: everything trapped in the above
The cleaning products
The resources you use: Of course it is safer to use lower concentrations of resources. However, stubborn stains are easier to remove with higher concentrations.
That means that you always have to keep your mind on it. Work in the direction where the wind comes from. Do you have a place in mind where you can rinse with lots of water? Do you have (basic) soap to neutralize acid afterwards? Gloves? Protective clothing? Glasses?
About the chemicals:
Hydrochloric acid is a dissolved gas, HCl, in water. Liquid bleach develops toxic chlorine gas, Cl2. You don't want to inhale these gases and have them close to your eyes and airways. You don't want the acid itself on your skin. So be careful. Always with sufficient air flow.
You don't want oxalic acid in your eyes and oxalic acid is a weak acid but avoid skin contact.
Keep everything away from children and pets and label packages. Intake is life-threatening with all substances.
Working with a mop is handy. Move gently to prevent splattering. You can do smaller jobs with, for example, a foam roller on a broomstick. Both rollers and the mop quickly deteriorate.
First test everything for small pieces.
Every time you work with a different agent, first rinse the surface with plenty of water while the surface is still wet with the chemicals. Then wipe off excess water with a wiper.
Organic dirt can be removed with bleach and detergent. Do not use it interchangeably, the effect of both means is negatively influenced and moreover a dangerous chlorine gas is created.
- Liquid bleach delivers quick results and leaves hardly any traces.
- Detergent has the advantage that enzymes start working for you that can dissolve certain stains and that the tiles are degreased.
Inorganic dirt is a bit more complex.
- Start with hydrochloric acid, for example 6 parts of water with 1 part of hydrochloric acid (30%), always acid with water, never the other way around and not inhale vapors. This is a spicy mixture to remove lime stains. You can make the hydrochloric acid solution even stronger but you can get stains. This is yellow iron chloride which is formed because hydrochloric acid dissolves the iron from the cement of the joint. Rinse before it dries.
- If iron stains, rust stains, remain, use oxalic acid. You can make a saturated solution of oxalic acid in a bottle, if crystals remain, you can add water to the bottle after use. You need very little of this and give it time to do its job. You can also mark rust spots on chair legs, etc. with oxalic acid.