Most people will experience mold in their bathroom and thats because mold only needs a couple things to grow. Warmth, Moisture and some type of Food Source is all mold needs to grow anywhere in your home. Mold that gets into your grout will penetrate and get behind the tile and eventually into the drywall or other wall materials and could end even up eating away the studs or floor boards in your bathroom. It is important to manage mold before you see it but once it is a problem you will have to do something to remove it.
The first thing to remember is that there are molds that are very bad for you and then there are common molds and fungus that may make you sick temporarily if you inhale or ingest them but during normal conditions and with some precaution you should not need to worry about getting sick. I suggest you wear a dust mask and gloves while working and if you find a serious mold problem that you use a respirator. Also always work in good ventilation especially when using chemicals like bleach.
When cleaning there are some things that you can do to see if the mold is just on the surface or in the grout it self. The first thing you want to try is using a 50% solution of household bleach and water in a spray bottle. Spray the area and keep it moist for about an hour. The grout will absorb the bleach and over the next hour or two it will kill any mold and it will clean the surface too. If you see some results you should repeat the process and see if you can cure your problem by just using bleach.
Unfortunately sometimes the problem is bigger and you will need to take more action to remove the mold problem.
If the tiles are tight and not loose on the wall you can try to regrout them and this might be as deep as the problem gets. If the problem is behind the tile then regrouting will not last long. It is a choice you will need to make and in the next step we will go over how you inspect the area by cutting an access port on the wall behind your tub or shower.
To replace the grout you will need to remove the grout that is in between the tile. They make small grout saws that fit between the tile and let you saw or grind out the grout. Grout is basically cement but it is very fine cement and easy to remove.
Once the grout is out you will need to replace it and you will have a variety of colors to choose at the home store. Normally it is better to go with a lighter color unless you have very dark tile and even then the contrast may be good.
Follow the directions on the box and mix the grout to a thick past using water and then rub it into the grout lines. After a few minutes you can begin to wipe away the excess. It will take a few tries to get the surface clean and it will leave a hazy coating until you do. After the new grout has cured overnight you can seal it with grout sealer. I would suggest you use a few applications of grout sealer in any area you know is moisture prone or will have direct water.
What If The Mold Problem Is Worse?
If you notice that the drywall behind your tile is spongy or that the tile seems to be bubbling out and coming off the wall you probably will end up having to take down the tile in that area and replace the drywall with cement board or green board which is a special drywall that is less effected by moisture and mold.
If the area of problem is in your bath tub or shower area and tile is coming off then making this repair might leave you without a place to shower for a couple days and you should understand this before you begin or before you hire someone to do the work.
One thing you can do to investigate the problem is cut a small hole in the drywall behind the problem area if you can access it. This might be a wall in a closet or hallway that is behind the problem. You should be able to see damage to the drywall and if the area behind it has a serious problem with water leaking and mold.
Take a screw driver or other small tool and press on the problem area and see if it is spongy or see if it is deteriorated. Mold will eat away the inside of drywall overtime.
If your drywall is in tact and in good condition you might be able to get away with simply removing the loose tile and then reattaching it with some mastic. Be careful as you remove the tile because they are very brittle and brake very easy when you are removing them.
If the problem is bigger and you do have drywall damage you shouldn’t be extremely concerned because replacing tile and drywall is not that difficult. You should check our other how tos on how to install tile but the process will mean that you remove the tile and drywall that is damaged and then replace it with new materials. If you find mold has got into your studs and is starting to eat them away you will need to replace them too and this also is not an end of the world situation because it is highly likely that the studs that are in your bathroom if they are not on the outside wall of your home then they will have no structural effect and all you will need to do is remove one and replace it with a new one. A few nails and you are done. Its not easy for the first time remodeler but it is very doable by most people that are determined.
Final Note
Mold should be managed by using bleach on your wet surfaces. After you take a bath or during your regular cleaning you should soak areas such as the walls and floors of your shower with a mild bleach solution for at least 15 minutes and this is the preferred method of killing mold and bacteria. Other products are fine but you will see by reading the back of that cleaner that it contains chlorine or bleach and this is the active ingredient that is doing the work.
Personally I won’t pay extra for bleach in a fancy bottle although I admit I use to until I started reading more about how bacteria and viruses are killed and then after taking flood remediation courses I learned the best thing to kill mold is bleach and that is what is used in flood areas after the drywall is removed and the home is stripped back to the studs.