Cement-based grout is by nature porous, and therefore not waterproof. It can be water repellent when modified with an additive, either latex or polymer-based, which effectively fills the micropores in the cement at a molecular level. In most tiling installations.
Hi, welcome to the forum, unfortunately cement based grouts are not waterproof, they can be sealed which helps but epoxy grout is waterproof and won't stain.. Be careful with the grout tool that you don't run it too deep and damage the former tray..
Grout and tile are NOT waterproof. Water will penetrate and pass through both grout and tile if saturated enough.
Whoever installed your floors most likely did not seal the grout because it needs time to harden and cure completely.
The Drawback of Using Grout Sealer
Moisture can still pass through most sealers, meaning grout isn't entirely waterproof even when sealed. Over time, grout in areas like bathrooms will naturally stain or show signs of aging, regardless of sealing.
Unsightly Grout Stains and Discoloration:
One of the most noticeable effects of neglected grout sealing is the gradual accumulation of stains and discoloration. Grout is porous by nature, which means it readily absorbs liquids, dirt, and debris.
For high-traffic areas, like the main bathroom, you should consider sealing it every six months, while low-traffic areas like the guest bathroom can be resealed every two years. If you are using epoxy grout, it might not be necessary to reseal it as it is highly water-resistant.
The price depends on the tile material and size, the condition of the grout, and whether you hire a professional or DIY. The average cost to seal grout is $150 to $250 for 160 square feet of space, including materials and labor, though the price depends on the size of your tiles and the condition of your grout.
What happens if grout gets wet before it cures? If you start exposing grout to water before it has properly dried it can lead to a few issues that you don't want to be dealing with. Typically it will weaken the grout and eventually it will start to crumble and even fall out.
How to Stop Grout Leakages. To maintain the integrity of grout, you will have to apply a grout sealer. It is necessary to apply the sealer after 1 to 2 years so that the grout remains intact and waterproof.
Most manufacturers of slurry grouts advise to keep the area damp with a sprinkle of the hose. So a very light shower can help to ease application and stop the slurry from drying on slab surfaces. However, anything heavier than a light drizzle is way too much rain for a slurry mix to cope with.
Grout Is Porous
Grout is the sandy, cement-based filler used between tiles. While grout seals the spaces between tiles, it is still porous, meaning water can seep through. Over time, the porous nature of grout allows moisture to penetrate deeper into the wall cavity.
Epoxy grout: Waterproof, durable, stain- and shrink-resistant. The best grout in shower walls, backsplashes and other surfaces susceptible to moisture or stains. Ideal for use with unglazed and other tiles.
A question we're often asked is, “how long should grout last in my bathroom last?” Grout doesn't last forever and has a lifespan of between eight and sixteen years, depending on your upkeep and treatment in your shower area specifically.
The next step for you to take is to inspect the grout properly. If it gets darker or changes color, it is a clear indicator that the grout hasn't been sealed.
The shortest time after laying tile that you can grout is 24 hours. However, it is much better to wait at least 48 hours before grouting. This is to give the mortar ample time to set and dry before pressure is applied.
The best answer, in a word, is money. It costs more time and material to seal grout and there is little or no perceived benefit (until, of course, the grout gets stained or starts to crack). A superior product would cost more to purchase and install, again for no perceived benefit over the less costly unsealed grout.
Any type of material can be susceptible to cracking if not sealed correctly. This will keep moisture out to keep the grout from deteriorating.
However, to achieve a clean finish and long-lasting results, you should always remove old grout before re-grouting.
Using Too Much Sealant
You might be tempted to use more grout sealer to get the job done quickly, but an excess amount can easily spill over onto the tiles. As a result, unnecessary time will have to be spent scrubbing the excess sealant off.
If your grout is visibly cracked or crumbling, it's likely going to be letting water behind your tiles. Even if your grout doesn't appear to be damaged, if it's not water-resistant it could potentially be the source of the leak.
You can seal the grout the day after you applied it or 100 years later. If it isn't dirty, seal all three sides of the shower with a tile sealer or masonry sealer. That will make the grout water-resistant, if not waterproof, and help prevent the growth of mold and dirt.