How can I Clean a Slate Floor?

There are several methods you can use to clean a slate floor, ranging from basic upkeep like dusting and warm water washing to more intensive methods like applying waterproof sealants and using commercial stone and grout cleaning products. A lot depends on where the floor is, how it was laid, and what sort of traffic it normally sees. People with slate floors in their bathrooms usually need to think about water damage more than a business with a slate lobby, for instance. In most cases, taking simple, every day steps to keep the floor in good condition is all that is required to keep things looking good through years of use, though homeowners should be wary of using regular household cleaners on their floors. As durable as it looks, slate is a porous substance that can easily be damaged by abrasive or acidic compounds.

One of the best ways to keep your floor clean is to dust it regularly. People don’t often think about dusting their floors in part because the dust that collects there isn’t always noticeable. Slate is generally somewhat multi-layered, though, which is to say that it isn’t always one smooth continuous surface. Simply sweeping the floor at the end of the day can remove particulates from the highest levels, but a more intensive dusting is usually needed to make sure that particulates are removed from all the cracks and crevices.

People with large slate floors are usually wise to invest in special “dust mops” or other specialized dusting tools to make the job go faster. Simply running a cloth over the stone can also work, but this usually works best in small rooms like bathrooms or entryways. Getting down on your hands and knees to dust an entire kitchen or living room floor can get tedious in a hurry. No matter how you do it, though, the main idea is to lift dust and debris off the stone.

Experts generally discourage the use of commercial dusting sprays; unless they have been specifically designed for slate or other stonework, they may actually do more harm than good. Slate is a very porous stone, which means that it easily absorbs chemicals and other substances. Most dusting sprays are harmless, but in most cases it’s better to be safe than sorry. A dry cloth is usually best, or one dampened with a bit of warm water if the dust seems particularly stubborn.

Regular mopping is also an important part of slate floor maintenance. It’s usually a good idea to get into a pattern of mopping about once a week for domestic flooring. Warm water is all you really need to get started, though it’s okay to use a little bit of mild dish detergent or soap if things are particularly dirty. You need to be careful when using soap to avoid leaving a greasy residue on your floor, though. If you put too much in the water, the stone might try to absorb some of the soap, which can leave the tiles slippery. Most professionals say to only use soap if your floors are really dirty, and even then to use only a small amount.

It’s important to mop the entire floor, not just the part that you see; this often means moving furniture and getting underneath or behind cabinets and other large fixtures. Pay attention to the grout, too. Most slate is set in tiles surrounded by grout, which may or may not be at the same level. Getting an even clean means working all parts of the floor in all corners of the room.

A lot of people with slate floors keep a separate stash of cleaning supplies only for use on the stone. Keeping dedicated dusters, mops, and brooms is a good way to help avoid contamination with chemicals and soaps, and can also limit the universe of dirt and other particulates that the tool comes into contact with.

Slate is generally resistant to staining, and most spills can be easily cleaned off with little more than soap and water. Food spills that aren’t noticed right away can leave marks, though, as can shoe scuffs and spills of things like paint or nail polish. As with most stains, it’s usually best to get moving as quickly as possible. The sooner you notice the blemish the better, though there is often hope for marks that have been sitting for a while.

The first thing to do is to see if the mark will come up with water and mild detergent. This may take some scrubbing, but it often works. If not, you should look into slate-specific cleaning tools. Many home improvement stores and hardware shops sell stone-friendly products that have been specially designed for more porous surfaces, and shouldn’t be as damaging as other commercial cleansers could be.

Particularly tough stains may need professional help, or at least the use of more high-powered tools. Depending on the size of the blemish, you may be able to buff it out using a rotary buffing machine. You may also be able to strip off the outer-most layer of the stone, though this is usually a last-ditch effort since it can actually be somewhat damaging for your floors. Stripping the stone can release a lot of dust, so you’ll probably want to wear a face mask to avoid breathing in any particulates.

If your floor is heavily used or is prone to spills or staining, it might make sense to consider a professional-grade sealant. Sealants cover the slate with an acrylic or other chemical coating that essentially acts as a shield, keeping dust, debris, and other materials off of the stone. Sealed floors are usually much more tolerant to soaps and other chemicals, though owners do have to be more vigilant for cracks and other aberrations. Most seals need to be replaced every one to two years, and can be quite costly.

Of course, it’s easiest to clean a slate floor if it isn’t very dirty to begin with, and a big part of slate upkeep is prevention. Using area rugs, welcome mats, and soft floor coverings is a good idea in high-traffic areas. Making a house rule to remove shoes when walking across the tiles can also be effective. You might also consider putting felt pads on the bottom of furniture so that it doesn’t scratch or mark the floor when you move it around.

There are a number of different varieties, colors, and styles of slate, and while they each share the same basic characteristics, they can have slightly different requirements when it comes to upkeep and tolerance of basic wear and tear. Stones from different parts of the world come in different colors and different textures. All slate is relatively thin and nearly all varieties are prone to chipping and cracking if they are mistreated. Basic gray slate is the most common, and it is also among the most durable. If you have a more exotic floor or are concerned about how to care for more specialized tiles, it’s probably a good idea to talk to the distributor or get a professional opinion on good cleaning practices.

Pretty much every sort of slate is sensitive to harsh chemicals, which is why basic water solutions are usually the best choice where regular cleaning is concerned. It is often actually the case that commercial floor cleaners can be truly damaging to slate, which makes reading labels very important. Products designed for wood, cement, or tile floors aren’t always very good for slate.

In particular, avoid anything that contains acid, as many standard bathroom cleaners do; alkaline-based cleaners should also be avoided. Never use abrasive cleaners or scouring powders without getting professional advice first. Even home remedies like vinegar and ammonia can damage slate if used improperly. These substances can sometimes be diluted enough to make them harmless, but it’s usually a good idea to just stick to water, mild soap if necessary, and slate-specific cleaners if things are really bad.