Grout restoration is a task that most first time bath renovators’ dread. Cracking, discolored, or stained grout full of dirt and mildew can leave almost any homeowner in despair – we've even known a few to consider moving so as to avoid it. Unfortunately, no matter what you've heard, reasoning with it will not make it go away, nor is there a Mildew Fairy who can magically make all your tiling problems disappear … there are however some things you can do that, almost almost as good as magic, will make your grout gleam like new again.
What is Grout?
Grout comes from the old English word Grut meaning “mud.” Grout is an underappreciated, and oft times under-maintained (is that even a word?) element of a bathroom (or kitchen) décor. You will more than likely never find yourself in someone’s house admiring their grout lines (unless, of course, they recently had to replace it and have dragged you over to brag) on the other hand, an otherwise pleasant bathroom can be gain significant icky points with unsightly stained, mildewed or moldy grout.
Though there are a few exceptions (the significantly more expensive epoxy resin based grout, for example), generally speaking grout is a simple recipe of Portland cement and colorant. This concrete like porous material not only adds strength to tiled surfaces but also subtly enhances (or significantly detracts from) the beauty of your tile facade. Grout is typically classified in two distinct types “Sanded” (the most common) and “Un-sanded.” As you may well guess the principle difference between the two is… well, sand. Sand in the mix increases the grout’s strength (like pebbles mixed into the concrete for sidewalks) and reduces the likelihood the grout will shrink and crack when cured. The sand however, also increases the bulk of the grout – which is why unsanded grout is used for thin grout lines too small for sanded grout to get into. Because unsanded has no sand, the problem with shrinking (and therefore cracking and pitting) is higher. Unsanded grout should only be used in grout lines SMALLER 1/8” (trust us, we’ve had to remove and replace more than enough unsanded grout from grout lines because of issues stemming from shrinking – even if the manufacturer’s say it’s okay for 1/8”, you don’t want to have to replace your brand new grout just days after you put it in… better safe than sorry).
Because of grout’s porous nature, if it is not properly sealed and maintained it WILL turn from appealing to atrocious in fairly short order. Not only is unsealed grout much more likely to retain dirt and grime, without a protective sealant coat it becomes a haven for the mold and mildew looking to set up residence in your damp shower stall. Given the opportunity, these little spores quickly find a home in the microscopic nooks and crannies of your grout lines and, before you know it, your shower stall has gone from gleaming to gross. Mold and mildew range in color from a sickly orange-pink, to mottled brown, to speckled or even solid black. We may turn up our nose and associate such “severe” problems with disreputable establishments, but the truth is, bathrooms suffering from grout issues are common remodeling issues and are far from confined to motels of ill repute. If you have recently pulled back your shower curtain and realized that you’re not the only one that could use a little freshening up, this blog is for you.
Seal That Stuff!
An old adage reminds us that “prevention is better than cure.” These words of wisdom ring true whether you are discussing matters of health or grout restoration (stickers and lollipops for being good at the doc’s office aside). If you have newly or recently installed tile (or can’t remember when or if your tile was sealed) you owe it to yourself to properly protect your tiled surfaces from the grime and other things that make you go “eww.” Sealant can be purchased at most hardware or flooring stores and applied in just a few minutes with a clean rag. As a general rule sealant should be applied about once a year – in very heavily used areas you may want to re-apply more frequently. Sealant does NOT waterproof the grout – don’t expect it to keep water from seeping through cracked grout lines – nor does it clean the grout for you. Before you apply the stuff spend a few minutes ensuring your grout lines are nice and clean and free of cracks and/or missing pieces. Sealant simply prevents the little ickies from getting a foothold.
Sometimes a “cure” becomes necessary – not every problem that may arise can be prevented (even those who have regular checkups can sometimes get sick). But despair not fellow hammerheads, it may not be as bad as you think, and even if it is… it’s probably not as bad as you think. More often than not a good cleanser and some elbow grease is all that is required to bring back your old grout’s luster. Other times you can offset the signs of your grout’s age by re-coloring it –restoring its vibrancy and adding a breath of fresh air to the entire room. Unfortunately, in the interest of full disclosure, there are times when the best remedy is to tear the old stuff out and replace it with new. This should be a last resort option (perhaps even behind hiding under the sink in hopes of catching the Mildew Fairy on the off chance we were wrong about her existence).
Clean it up
Before you jump right into your “restoration” process we fist need to properly evaluate the extent of the damage. To do this the area must be thoroughly cleaned. This includes both tile and grouted surfaces. There are several options – from simple cleansers, to industrial strength strippers, to homemade remedies that can aid in this process.
Tile and Grout Cleansers
Oxygen bleach is our preferred cleansing method. It’s simple, effective, and safe for people, pets, and the environment (unlike its chlorine based counterpart which, although also an effective cleanser, poses significantly higher risks to the user and the environment, not to mention any fabrics that come in contact with it). Oxygen bleaches come in either a powder form or a liquid (hydrogen peroxide). As the name implies, it uses oxygen to do the “dirty work,” or rather oxygen molecules. Powdered bleaches are made by treating natural soda ash or natural borax with hydrogen peroxide. These materials can absorb the oxygen while remaining free flowing solids. Upon dissolving in water, they release the oxygen. The released oxygen molecules then go out “like a cruise missile,” as one site refers them to, and attacks the stain. What actually happens has less to do with military arsenals than it does with molecular science. The freed oxygen molecule attaches to the molecules of the stain. This changes the molecular structure of said stain so that it either has no color or else reflects color outside the visible spectrum, and walla you’ve cleaned your grout with oxygen. The original material (now without an extra oxygen molecule) becomes little more than water (in the case of hydrogen peroxide, or water and soda ash if it was a powdered mix).
As powerful as these little free oxygen molecules are, they do have their limitations. Only surface stains, stains that have not yet penetrated the material, are affected (that’s why they don't bleach dyed clothes). Grime and mildew that are left long enough can set, meaning they may be beyond the reach of our friendly oxygen bleach. So it pays to get rid of the problem as soon as possible. More often than not however the dirt and such is only surface grime. If the first application doesn’t remove all the discoloration don’t despair, it is not uncommon to need multiple applications to completely restore your grout’s luster (remember, there are a lot of little nooks and crannies for the gunk to hide in)
When shopping for oxygen bleaches, search out ones that contain the highest amount of active ingredient as allowed by law. Generally speaking these higher quality bleaches are manufactured in the
(Beware of lesser quality bleaches which often contain vast amounts of filler that do nothing but take up space in the bottle). Inferior bleaching products are easy to spot because they are priced far below quality ones. Our recommendation is to buy the best cleanser you can. You’ll thank yourself later. USA
Acid Based Cleansers
Acidic cleaners work by etching (removing) thin layers of grout. The acids remove the layer(s) that are gunked up thus restoring the grout to "original" pristine condition. These industrial strength chemicals are best suited for bathrooms where significant mold or mildew is present. They can make quick work of cleaning tiled surfaces but come with some considerable draw backs, not the least of which is the safety issues involved with using and properly storing them. Additionally, care must be taken to neutralize the chemical reaction or the acids will continue to eat away at the grout. The very reason these cleansers are so effective at eradicating grout problems is the very reason why, if you are not careful to take the proper safety precautions, your weekend project could wind up making you really sick. ALWAYS follow the manufacturer warnings and safety labels marked on the containers – make sure to wear the proper safety gear and ventilate the area as best you can.
Homemade concoctions make use of products you probably already have around the house. In our experience few of these are more than moderately effective. A favorite seems to be vinegar and baking soda. While admittedly it makes a pretty cool bubbling effect we’ve never had much success using it to clean grout.
Keep in mind that even homemade concoctions are not meant to be ingested – just because you make it with products from the pantry does not mean you need to be any less vigilant in the way you store or use these products. Always keep cleansers and other chemicals safely out of reach of children and keep away from your eyes, mouth, and/or breathing them. Also, be extremely cautious of recipes that call for mixing different chemicals some fumes can be toxic and can be fatal.
The colorant in grout naturally fades over time. This process is accelerated with the presence of mildew or mold. Once your grout is clean you may find the color you remember has faded and is in need of a little touch-up. Providing your grout is not cracked, but merely discolored, a good option is applying a grout dye. Coloring your grout is an easy grout restoration process. Quite honestly it works better on sanded than unsanded grout, but there are several products that claim to work well on either. Grout stains are available through your local hardware store or flooring outlet as well as online. You will generally have to choose a shade slightly darker than your current color - it's much more difficult to go lighter as the original color will almost always bleed through. With this in mind, go wild – you’ll be surprised how much different the space looks with even a slightly different color. A good rule of thumb is to pick a color that is present but not prominent in your tile. The color of the grout will bring this color out and give new life to the bathroom.
As with any color application product, before you go smearing your chosen color all over your grout it's a good idea to test it in a small unnoticeable area (a good concealable spot is around the faucet or handles). Follow the directions on the packaging but be sure to mask any areas you don’t want colored especially if you have semi-porous tile.
It's Come Down to This
If you’ve come to this point you’ve probably recently finished cussing at your grout as you've realized the extent of the damage and what that means for your weekend. Sometimes the best thing to do is remove the grout and begin anew. Removing grout can be a labor intensive project - don't forget to take breaks and drink water. The tools you will need include a utility knife, dust mask, eye protection, a vacuum (preferably a shop vac) and several hours to do your work - if possible, seriously consider investing in an oscillating saw and a grout removal blade. .
• Remove grout from thin seams with a utility knife. Keep a stack of blades available to change as needed. Because thinner lines are typically unsanded they are usually easier to remove than their sanded counterpart, but that does not mean the grout won’t be stubborn. Have a mallet handy to help if needed in the process. Wider seams will require a grout removal tool. If you are doing it by hand you will want to pick up a grout saw (a small hand tool with carbide "sand paper" on the end), bear in mind, unless the area you are re-grouting is very small you will more than likely need to dedicate more than one weekend to the project. To speed up the process, we recommend investing in a power tool. Several choices are available, most work well at decreasing the time you spend hating your grout. The price points range from fairly inexpensive to practically exorbitant. Our preference falls somewhere in the middle. We’ve found good success with the reliable Dremel brand (A Dremel multi-max with a carbide grout blade makes quick work of the project – plus there is a variety of uses you can get out of this tool post grout removal). For about a third the price of the Dremel you can pick up an oscillating saw at Harbor Freight and a diamond grit grout blade. It's not the highest quality tool but it still manages to do a very respectable job for significantly fewer bills. We have even seen grout removal blades for use with a reciprocating saw. We haven't used these, but in our opinion a reciprocating saw outfitted for the job would greatly increase your chances of marring your tile should the saw skip.
What ever your choice, if you are using a power tool for grout removal, you will need to wear a mask and eye protection – it can be a very dusty process and you don't want a stray piece to kick up in your eye. Whatever method you choose, you need to remove all or most of the grout. Remember: you aren’t just scraping the grout you are removing it, or at least enough to ensure a good adhesion for the new grout.
• After the old grout has been removed clean the grout lines with a vacuum. Check to ensure that all bits and pieces of grout have been removed before you apply the new stuff.
• Mix your grout. There are pre-mixed grouts available but they just don’t hold up as well as the mix-it-yourself option. The pre-mixed formulas also include an acrylic additive which makes it harder to work with. Also, there are areas where pre-mixes are not suited for (ie your shower floor – the shower will actually wash the grout right out of the lines). Go with the powdered mix and a bucket. Don some rubber gloves add the recommended water and mix it like a mud pie. You can purchase mixing blades but we found it easier to mix by hand (do not try this without gloves unless you like EXTREMELY dry hands for a week). You can then use your hands and the rubber gloves in lieu of a grout float. Whether you decide to mix it with a paddle or your hands rubber gloves are a good idea (Why risk messing up the new manicure)?
• Apply the new grout using a grout float (or your rubber glove clad hands). You will also need a bucket of water and a sponge to wipe away the excess grout and a clean rag. Use the correct type of grout – unsanded should only be used on grout lines THINNER than 1/8”, use sanded for everything else (yes, including polished stone). DO NOT leave excess grout sitting on tile to cure. Wipe the tile down as you go, changing the water as needed. After you have finished wiping everything down wait a few hours then wipe the haze off with a clean rag.
• Allow the area to dry. Grout cures harder if it is allowed to dry slowly. Drying slower also reduces cracking. We prefer to cover the wet grout with plastic to allow the moisture to slowly evaporate over the course of a few days. Depending on your location you may not need to do this. Once the grout has dried, seal it with the proper sealant. You’re all done. Remember to reseal the grout at least annually – you probably don’t want to have to go through this again.