You can apply new grout right over the top of the old grout. To do this, all you need is a grout removal tool. Use the tool to strike out the old grout, making sure the depth is at least 2mm, which is about the thickness of two dimes stacked one on top of the other.
The short answer is, “no.” You cannot put new grout over old grout. With regard to filling in holes and cracks on the surfaces in our homes, we might compare grout repair to drywall repair.
The primary reason why grout deteriorates is that it was not mixed and installed properly. If too much water is added to the grout at install, it will not seal with the required density to withstand prolonged exposure to moisture and (most of all) water.
The best line of defense and protection for your grout is to have it sealed. Sealed grout will not only get the protection it needs against crumbling, but it will also be protected against heavy staining as well. Your tile and grout need to be professionally cleaned before getting sealed for best results.
The grout should be dug out a minimum of 3mm deep (preferably deeper) so that new grout can have a firm base and a larger surface area of the sides of the tiles to adhere to. Do not attempt to apply new grout over the damaged existing grout.
Regrouting can be a worthwhile home improvement project that keeps your floors looking good as new. It makes your tiles more resistant to mould, prevents water from seeping behind the shower floors and walls, and ensures they have a longer life span.
Putting new grout over old grout is not as complicated as a complete re-grout as it does not require the removal of the old grout. It can also strengthen the surface to increase water resistance and make it less susceptible to impurities.
If your grout is a few years old, it's normal that in time, it will crack. This results from a few key causes: Exposure To The Elements. A common problem for wet areas in the home, like the bathroom or shower, grout tends to crack here as a build-up of water slowly eats away at the material.
Epoxy grout is superior compared to its cement-based counterparts and can last longer. Some epoxy grout doesn't even require sealing, but it can still begin to have issues over time.
Grout doesn't last forever. You can expect a lifespan between eight and sixteen years. Its lifespan will vary depending on how you treat your shower. Odds are, you have no idea when your grout was installed.
Regrouting is the best option when tiles and grout begin to show signs of discoloration or the stains are so deep that they cannot be removed. As grout ages, it naturally deviates from its original color. If the white grout turns yellow or is covered with stains, you must regrout very soon.
Re-grouting is more affordable than retiling as far as bathroom flooring options go. This DIY project can be done in about four hours, which makes it much faster than retiling.
If you don't have any serious damage to cover, you might pay as little as $1.70 to $5 per square foot. This would cover a basic cleanup job with some “spot” grout removal. On the other hand, a full professional removal and regrouting goes for around $10 to $25 per square foot.
If you haven't kept up with grout maintenance, the once-white grout lines between your ceramic tiles may now appear gray, brown, or black. This discoloration is an accumulation of dirt, food particles, and—in the case of shower tile grout—mold.
Pin holes, large holes, cracks or missing grout ruin the beauty and aesthetics of your showers. The missing grout spaces accumulate water and the cracks absorb moisture, further leading to mold and mildew breeding. Mold and mildew occur in places that are constantly damp.
Grout is porous and therefore absorbs liquids. Because of this, the reason you should not seal your tile grout is that the sealer's liquid chemicals combine with the grout to create a surface that is actually much more difficult to clean.
What type of grout sealer to use in a shower? We recommend that you always use a VOC-compliant and solvent based formula that can penetrate shower tile grout. Ideally you want a product that not only protects against oil and water-based stains but also lets the grout surface breathe properly.
You can remedy this by using caulk to fill in the cracks and restore the look of the grout. First, remove all loose and cracked grout with a grout saw or Dremel tool. Apply the caulk gently to the cracks, smoothing it down with a plastic spoon. You can also wet your fingers and smooth the caulk by hand.