How To Clean A Moldy Shower and Kill The Shower Mold

Shower Mold Cleaning Tips

By Troy Cantini

Black or red mold can make your tile shower look ugly and create an unsanitary condition in your home.  Toxic mold growing in the shower grout can start getting into the walls of your home. Bacteria, germs and other harmful pathogens can also start growing in your shower that can cause health problems for your family and pets.

moldy tile shower

Cleaning and removing the mold in your shower requires a systematic approach using a combination of cleaning products and procedures.  You not only want to clean up the mold but to also kill the mold that is growing in the porous grout lines. Killing the mold win ensure that it will not readily re grow in the shower when the shower is used again.

Moldy shower grout and caulk are typically the main concerns in a tile shower.  The porous grout is a perfect breading grout for mold to grow. If the grout has not been adequately sealed then the mold can more easily grow in the grout lines. Moldy caulk is another issue that is almost always present in a moldy shower. If cheap latex or siliconized caulks were used then the mold can actually grow in the caulking. It is almost always necessary to remove this moldy caulk let the shower thoroughly dry out to ensure that any mold under the caulking has been killed and removed. Then only 100% silicone caulking should be used to replace the moldy shower caulk.

When cleaning moldy shower grout in ceramic tile showers a professional acidic cleaning product works best to clean the shower and kill the mold in the grout.  Stonetech Restore is a mild acidic tile and grout cleaning product that is extremely effective at killing and removing mold in ceramic tile showers. You can only use Stonetech Restore on ceramic or porcelain tile installations because it will etch delicate stone shower tiles. You can use Stonetech restore on some acid resistant stones such as some types of slate or granite but you should always test these surfaces first before using the Stonetech Restore on them. When cleaning stone tile showers a professional level non acidic soap scum remover must be used for cleaning the shower and removing the shower mold.

When cleaning moldy shower grout in a stone tile shower a professional grade non acidic soap scum remover works best to remove the soap scum.  MB-3 is a non acidic soap scum remover that is specially formulated to clean soap scum in stone tile showers. It is extremely effective soap scum remover that will not damage, discolor or etch delicate stone tiles. You can also use the MB-3 on ceramic and porcelain tiles but it is more expensive and to use for normal ceramic or porcelain tile cleaning. When trying to remove soap scum in stone tile showers MB-3 is the best available option.

applying soap scum remover to shower

Cleaning and removing the soap scum is the first step to getting rid of the mold in a tile shower.  Soap scum will also contain organic shampoos and body oils that can allow mold to readily grow. You should spray on the soap scum remover and allow it to dwell on the tiles and grout for at least 20 minutes. You should see a fizzing effect on the grout if you are using the acidic cleaner as it reacts with and cleans the grout. You should not allow the soap scum remover to dry on the tiles and grout so keep adding product for the 20 minute dwell time as needed.

scrubbing away shower mold

After you have allowed the soap scum remover to loosen up the soap scum then you should scrub away the soap scum with a scrub pad paying particular attention to the grout lines.  Often there will be a heavy layer of soap scum on the grout lines so you need to ensure that you scrub away all of the soap scum from the grout. Most ceramic and porcelain tile showers are scratch resistant so you can use an aggressive scrub pad to scrub away at the soap scum. When scrubbing softer stone tiles a soft scrub pad should be used that will not scratch the finish of the stone tiles.

When you are done cleaning up and removing the soap scum then you should use a sponge to thoroughly rinse away all of the excess soap scum remover.  It is important to remove all of the soap scum and cleaning products from the shower tile and grout.  In many showers with heavy layers of soap scum buildup you may be forced to repeat the soap scum removing process a second or third time to ensure you have gotten rid of all traces of soap scum.

The next step in the mold cleaning process is to use bleach or a professional mold killing product like MB-9 to kill the shower mold.  Bleach is safe to use on ceramic and porcelain tile showers. MB-9 is a professional mold killing product that is safe for stone tile showers. Bleach can be somehat toxic and should not be used in stone tile showers. Bleach is almost as effective as MB-9 for killing shower mold and will save you some money when killing the mold in a ceramic or porcelain tile shower.

You should mix the bleach one part bleach with one part water and spray it or the MB-9 directly on the tile and grout and ensure that you get a good saturation of the mold killing solution on the moldy shower grout.  Allow 5-10 minutes dwell time for the bleach or MB-9 solution to react with and kill the mold in the porous grout lines. Wear rubber gloves when using bleach or MB-9 and do not get any of these cleaning solutions on good clothes, carpets or other fabrics. Both MB-9 and bleach solutions will discolor most fabrics.

removing moldy caulk in a tile shower

In most cases a shower that has got mold growing in it will also have caulking that has become black and moldy.  Mold can not be cleaned from caulk after it has become black and moldy because the mold is actually growing in the caulk.  In most cases the caulk must be removed and replaced to ensure that your shower is totally mold free. You can use a razor blade scraping tool to remove the old moldy caulk.  You can read more about how to recaulk a shower here.

When you are done cleaning the mold in you shower grout and you have removed the moldy caulk then you should wipe the shower dry with a towel or paper towels and let the shower dry overnight.  Thoroughly drying the shower will ensure that the mold will not readily grow back in the porous shower grout. Mold must have a constant source of water to survive so drying out the shower will kill any remaining mold in your walls and not allow the mold to regrow in the grout.

If you feel that water has gotten behind your tile and grout and into the walls then you may want to dry out the shower for a few days after you have completed the mold cleaning procedure.  It can also be helpful to set up a dehumidifier or some fans in your shower to get your shower as dry as possible in the shortest amount of time.

sealing shower grout

After the shower has dried out then you should seal the grout with a quality tile and grout sealer product  Consumer level tile and grout sealers from home improvement stores will not provide much protection against water penetrating into porous tiles and grout. Also consumer grade sealers will not last long and will wear out in a few months of shower use. A one (1) quart container of sealer will be enough for most standard size showers and give you enough sealer to apply 2 coats of the sealer for the ultimate protection against mold in your tile tile shower.

Apply the sealer using a brush tipped applicator to just the grout lines.  Keep applying sealer to the grout for 5-10 minutes and do not allow the sealer to dry on the tile surfaces. Keep applying more sealer as necessary so that the sealer can be completely absorbed by the porous grout.

After you are done applying the sealer then wipe up any residual sealer from the shower tiles and grout with a cotton towel or paper towels. Ensure that all traces of sealer has been removed from the tile surfaces and inspect the tiles from many angles to ensure that you don't have any streaks of sealer that have dried on the tiles. If necessary re-saturate any area of tiles with sealer to remove any streaks of sealer where it has dried on the tile surfaces. You should allow the sealer at least 30 minutes time to dry and then you should apply a second coat of sealer to the grout lines.

mold free clean ceramic tile shower

Caulking the shower is the final step in the ceramic tile shower mold cleaning and removal process. You should tape up all the shower seems and apply a professional 100% silicone caulk like Laticrete Latasil to the shower. Smaller showers will take one tube of the laticrete Latasil while larger showers will take two (2) tubes of the Laticrete Latasil caulk. You should only use 100% silicone caulk so that mold will not quickly grow in the new caulk. Laticrete Latasil 100% silicone caulk comes in many colors to choose from if you need to match the color of your tiles. If you just need a white or almond colored caulk then GE Silicone II 100% silicone caulk from the home improvement stores works great too.

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