There are many mistakes that are commonly made when sealing terracotta tiles. This first mistake could easily be avoided if the proper time is put into getting them properly prepared for sealing. Many customers I’ve dealt with over the years, including myself have bought Saltillo terracotta tiles that were sealed in Mexico. These handmade tiles are set in the sun before the baking process while setting up they’re laid out for days, getting walked on by chickens, dogs, and quite a few other critters. Then there’s dust from the unpaved roads and the factory itself. the clay is still wet and the factory dust sucks the moisture from the tile making it have a really strong bond to the surface of the tile.I don’t think people understand how important it is to remove this dust correctly before sealing. Customers and DIYers alike keep bringing it to my attention, and I’ve also had this problem with tiles I’ve bought.
Like everything preparation is most important, and it’s no different with these tiles. Here are two important reasons to get this dust removed.

1. Once sealed with multiple layers of a topical coating sealer (desert sealer) ANY dirt from animals or dust from the roads are now trapped and sealed to the tile. Making them look years older when they should look brand new.

2.Your tiles need a watertight seal. When applying the sealer without removing dirt and dust the sealer adheres to the fine dust, which keeps the sealer from getting into the pores of the terracotta tiles and creating a strong bond.
Once you’re complete and living on your newly installed floors, you’ll notice your sealer is starting to peel and flake off the floor where its adhesion was the weakest.
A gentleman from Utah who follows my videos on YouTube had this problem as well, but he bought them raw and unsealed, and wiped them down with a wet rag. He then sealed his tiles with four coats, installed them then started living on them and peeling and flaking began immediately. My guess is that they were not prepped right. The best way to prep Saltillo terracotta tile for sealing: First you lay them out on tarps to keep the dust limited, once you’ve laid out the tile you’re going to scrub the surface and the sides of the tile with an abrasive scrubber (not sandpaper). Once you have scrubbed the surface and the sides vacuum all the loose dust then wipe down all tiles with a damp grout sponge to remove the last of the fine dust, let dry and they’re ready to seal and your sealer and will have a true bond.

A second common mistake is not applying enough sealer. Most sealers come with instructions on how to use it, this is where I think the people who make this stuff have actually never used their own product. Two to four coats of these topical coating sealers are not enough. Each tile has it own porosity, where one tile may seal with four coats and another tile may take up to seven coats, that’s why I recommend at least six to seven to build up the layers to create a more uniform sheen throughout the floor, eliminating highs and lows and giving you a bulletproof surface that’ll be more durable and easy to clean.
If you’re doing restoration sealing just apply four layers on the surface and in the grout, let dry overnight and then apply three more layers. If brand new once cleaned as described above, apply four coats, let dry, then grout the floor and let dry for 48 hours, apply three more layers really focusing your efforts on making sure you’re getting the sealer in the grout as well as the surface of the Saltillo. A third common mistake is that contractors convince homeowners to put these shiny topical sealers on tile exterior. This makes them slippery when there’s any type of moisture on the surface such as morning dew and water from the sprinklers and rain, these sealers no matter the brand, will not hold up to these outside elements. The elements take their toll on these sealers and they’ll begin to break down and start to peel off, turn cloudy, hazy and are susceptible to watermarks caused by moisture penetrating the sealer then getting trapped below the sealer. This will cause powder efflorescence and in extreme cases, calcium and lime build up.

Once cleaning properly you can use a penetrating sealer which leaves your tiles looking natural, with a watertight seal. There’s also a penetrating color enhancing that also doubles as a watertight sealer, the main function or this sealer is to enhance the color of the tile, giving it a wetter look. These sealers will hold through the elements better than the topical coating sealers and are way easier to clean, maintain, and most important of all less slippery.

DON’T MAKE THESE 4 MENTAL MISTAKES THAT YOU’LL REGRET LATER
1.Taping off your walls and surrounding hardwood floors/carpet, so when you’re applying your sealer you’re not shinning the wall and surrounding areas.
2.Make sure to vacuum two times before sealing and two more times between coats, you may want to consider vacuuming surrounding area as well to make sure you get all the DOG HAIR, HUMAN HAIR, and any other debris that could probably get stuck in the sealer.
3.Make sure the tiles are fully dry between coats, it will give you a better and overall stronger and durable bond to the surface. when wet the sealer sinks in and the moisture softens the sealer making it harder to dry, and sometimes making it turn white and cloudy.
4.FOOTSTEPS IN THE SEALER! Make sure you keep your self-squared while sealing, moving backward from the wall to the exit door. Do not trap yourself in the corner.