How To Remove Mold and Re-grout a Tile Shower Stall

In this How To we will be covering the maintenance of a tile shower stall that has become very moldy.

A person asks what the best method to cure and them prevent black mold from growing in their shower stall. They also ask about grout sealers and specifically hydrophobic liquids that are now being used to protect painted surfaces.

How to cure Mold problems in Tile Shower Stalls

A properly designed and maintained shower should not become moldy however it is important to understand why this happens before you try to cure the problem. In the environment everything is covered with bacteria or molds that are not normally visible to the eye. Yes even you, your pet and your favorite set of dishes have mold on them.

Now you might be thinking it can’t be everywhere because It doesn’t grow all over the house. Well thats the problem. Mold needs food, moisture and warmth to grow. Your bathroom and kitchen provide the best surfaces for its growth and this is where you will see the problem. If you were to place a dish of water under your bed and kept it moist for a few weeks theres a high probability that you would come back to a plate full of mold.

Ok so to prevent the mold from growing you have to kill it and you should also reduce the chance it will come back by wiping down your shower after you take one if it is a humid time of year.

To kill mold the best product is straight bleach which is normally about 5% strength in water for clothes washing. Fill an empty spray bottle and keep it under your sink and spray down the shower between weekly cleaning if you have a mold problem.

To remove the mold you will need to use a grout saw which is a special tool that will get between the tiles and scrape out the old grout. Be careful using it because you could chip a tile pretty easy if it is older or made of a weaker clay material.

Because doing this might be messy you should take down your shower curtain and tape it to the sides of the tub or to the floor of the shower stall. You can then collect all the material and throw away the shower curtain and use a new one.

After removing the grout I would suggest spraying down the surface with bleach to allow it to leach into the surface behind the tile. Since you are only using a little bit of liquid it should not be a problem but do not over do it because once the grout is removed so is the ability of the shower surface to retain water and not seep through into the lower level’s ceiling.

Using a moist towel wipe down the shower and prepare for grouting.

You should mix the grout as recommended and the type of grout is important. You want to get a grout that matches in color with the tile installed. Normally this is a gray or almond or white color. You want a color that is conventional and not contrasting.

The type of grout you use should be unsanded for gaps under 1/4 inch and sanded for gaps that are 1/4 inch and larger. A store representative should be able to help you when you are buying your grout.

You really do not need that much grout when doing this job normally a small 12 ounce container will work well. Water can be used for mixing however some companies suggest a liquid that can aid in flow and reduce mold growth.

Apply the grout on a diagonal to the grout line don’t follow the line or go at it at 90deg or you will got get a good filled gap.

Once it has set up you can then wipe down the surface and remove the extra grout.

It will probably take you a few cleanings to get all of the grout off the surface of the tile. It will look slightly milky.

If the manufacturer suggests sealing the grout you can but it should not be necessary and it could result in a dangerously slippery surface. Normally grout sealer is used on floor tile to prevent discoloration from foot traffic and dirt.

In the corners you can follow up with a bead of tub and tile caulk to hit any areas where you have concerns that leaking may occur.  If you have a tub you should do this around the top rim of the tub where it meets the tile and it will provide good sealing and a nice appearance.

How to prevent mold from coming back

Preventing mold is a matter of your cleaning schedule. If you live in a very humid area like Hawaii or Washington State you may want to use an after shower spray to treat your shower after every bath. This can be made of a diluted bleach solution or purchased.

Final Note

Mold can cause health concerns for most people not just the elderly or children but it is even more important to remove from your home if you have someone who is sick or with a low tolerance for this type of problem.

Bleach is the best method of removing mold. When you purchase your cleaners at the store your bottle of cleaner will tell you the percentage of bleach. Also bleach bottles used for clothes washing should tell you the percentage of chlorine in water solution.

Bleach must be in contact with the mold or bacteria long enough to kill it. If it is not then the cleaning process is not worth doing.

Normally when clean the house I bleach my shower first and then go on to do everything else.This gives me at least an hour and normally two for the bleach to kill the mold in the shower. Then I wash down the shower with water to remove any bleach and clean the shower with cleaners to remove soap scum or dirt.

Bath mats that do not come clean with direct bleach within an hour should be thrown away. You can normally expect to throw them away every 6 months or so.. maybe longer or less depending on your home.