Slate tiles are often used for fireplaces and patios, but it is highly susceptible to stains from water and hard, calcified deposited stains under pots and other items. So how do you clean your slate if it is full of stains, do not worry. These white stains (sometimes brown or black) can be removed without too much time or trouble. You can even remove spilled paint and other residues using a natural process.
First you need to sweep the area clear. You are going to be scrubbing the stains, and if you have dirt or grime in the area it can become muddy and that will make it difficult to see if you are actually removing the stains.
Then you prepare your cleaning solution. Combine half a cup of vinegar, half a cup of lemon juice and half a cup of baking soda in a bowl. This forms a paste, you can add a little water or more baking soda to make the paste thick but manageable.
Now you layer a thick coating of the paste over the stains, then lay a damp, warm cloth over the entire treatment area. Leave it there for about 20 minutes.
Use a damp scrub brush and start scrubbing the stains in firm circular motions. Rinse the area regularly to see how effective your cleaning efforts are, since the paste can get in the way.
On tough spots you can use steel wool, remember to use gentle pressure and circular movements.
Once you are certain that the stains have been removed, rinse the area thoroughly. If there are plants around the slate, such as next to a patio, use a lot of water to rinse the area, so that the vinegar does not affect the plants.
Allow to dry, and the area should be stain free.
I own a professional cleaning services company, and I use this method regularly.