You can grout with your finger. First apply the grout with a float, then neaten the grout line by running your finger along the lines. Leave to harden off a little before wiping the excess grout from the tiles' surfaces. After you have wiped, check the lines and again use your finger to create a neat finish.
Using your hands to apply the grout allows you to work the grout into those spaces that a grout float might miss. When you use your fingers and hands as grouting tools, your sense of touch helps ensure you fill all the spaces between the mosaic tiles.
Plastic Spatula
You can also use the spatula to spread the grout just like you would spread frosting on a cake. A spatula is flexible and soft enough that it will not catch on the edge of a tile while you are grouting.
If this is the case, the colour tint and epoxy mix will contrast with the tiles. Grouting is a simple task and can be done by most DIY enthusiasts. As long as you have the essential tools and grouting materials, the application is not a job that requires the services of professionals.
Most types of grout, including cement grout and other epoxy grout products, are labeled as hazardous and corrosive, and are accompanied by warnings to avoid skin and eye contact as well as instructions for specialized disposal methods.
If your tile is looking worse for the wear, you might be able to spruce things up with a simple regrout job. As long as your tiles are adhered properly and in good condition, laying new grout is a job almost any homeowner can tackle on their own.
Sponging the grout too soon will pull it out of the joints, so let it set for about 15 minutes. After that, use a damp sponge to clean the face of the tiles in a light, circular motion. Next, clean the sponge and go over the tile again, wiping at a slight diagonal to the joint.
A good rule of thumb is to clean as you go, working in small sections. This is especially important if the grout application is slow-going. Optimally, no more than 30 minutes should pass for the initial wiping off of excess grout.
A grout float looks like a trowel but has rubber base instead of a metal base. With this tool, you can easily and quickly capture grout and apply it to the surface of the tiles. A grout float can also effectively force grout into the joints between the tiles or remove excess grout before the grout dries.
Before wiping off any excess product, let the grout harden and then test it with your finger. Scrubbing the wall will be ineffective as it just moves the product around, instead of cleaning it effectively. Instead, you'll want to use a damp, not soaking wet, sponge to clean the entire area in long, continuous strokes.
Grout is mildly caustic and can irritate skin, sometimes severely if you have sensitive skin. The sand and rubbing required in grouting aggravate the problem. Wear rubber gloves while grouting to protect your skin. Grout contains powdered silica (sand) and is slightly caustic due to the lime it contains.
Grout is porous so that it will absorb vapour and moisture. To prevent moisture from being trapped behind the grout and tiles, which can lead to mould and rot, the grout needs to breathe.
Dampen the substrate and tiles
The use of water is an important part of the entire installation process. Before grouting, use a clean sponge with potable water to dampen the substrate throughout the tile installation. Next, dampen the edges of the tiles with a light water spray bottle.
Grout can be messy, so learn everything you can here before tackling your next tiling job.
Wait for the grout to dry before using grout haze remover. Typically this takes around 24 to 48 hours, but you should consult your grout's packaging for the exact duration. However, don't wait too long.
You should not wait for more than three hours after the grout has set to remove the haze. If you remove the grout haze within three hours of setting, you can do so with the help of a clean damp sponge.
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.
Installation
With the use of cement surfacers after grouting the tiles, with the grout still fresh, any excess grout should be removed immediately with a sponge and plenty water. A few days after laying, clean thoroughly with buffered acids to completely remove and dissolve any residue.
ANSWER - It is possible to grout over existing grout if there is enough depth to do so. 1/8 inch depth may or may not be adequate depending on the type of grout used. A latex modified grout may work, but you have to properly clean the existing grout to ensure the new grout adequately bonds.
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.
Average cost only $445 to $795 including GST
*Should the shower be too deteriorated then we may suggest alternative solutions such as tiling, waterproofing and or renovations works.