Medium Gray Mosaic Grout 2 lb is a traditional portland-cement grout for mosaic tile and comes in the form of dry powder with sand pre-blended into it for strength. The Gray color is highly recommended because a medium gray contrasts most tile colors (except for grays and light blues). We have more advice below about choosing grout colors and an explanation on why you want your grout color to CONTRAST tile colors instead of matching tile colors. If you need a slightly darker grout, you could mix this grout with some Charcoal Mosaic Grout in a ratio of roughly 50:50.
Medium Gray Mosaic Grout
- traditional portland-cement grout with sand
- approximately 2 pounds
- dry powder in plastic tub
- just add water (about 1/2 cup)
How To Grout Mosaic Art
Mix the powdered grout with approximately 1/2 cup of water until a dough-like consistency is achieved. Follow these instructions for How To Grout.
Sanded? Unsanded? Epoxy?
Our grout is a conventional grout, which means that it is portland cement (anhydrous lime), sand and mineral pigments. It is not one of the new epoxy-based grouts. Our grout is a dry powder pre-blended with sand. Just add water. Note that unsanded grout is only used for sealing hairline cracks. Grout is almost never used without sand because you need sand. Sand gives grout tensile strength the same way gravel gives concrete tensile strength.
Should You Buy Grout Locally?
Our grout is small convenience packs for individual projects. Grout can be purchased locally in very large bags cheaply at building material stores, and your don’t have to pay shipping. If you are trying to grout a large mural or a whole class’s mosaics, you should probably buy grout locally in a large bag like building contractors use. However, the large bags are more difficult to pour without creating a lot of dust, which is a safety issue, and they are difficult to pick up, handle and store. It makes sense to buy our grout in the convenient tubs for small projects, but you should never buy more than 3 or 4 containers. Instead, go to your local building material store and save money.
Choosing A Grout Color
Contrast Yes. Match No.
Grout can totally change the look of a mosaic, and it is possible to ruin (at least temporarily) a mosaic you have worked on for weeks merely by applying a wrong color grout. Grout is supposed to CONTRAST tile color not match it. Visually, the purpose of the grout line is to separate the tiles. If your grout color is too close to your grout color, then it all runs together visually and individual tiles do not stand out. (Trust us: That is something that you won’t like once you see it.) If you do happen to “ruin” your mosaic with the wrong color grout, then you can remove the grout with a Grout Removal Tool and re-grout.
Grout As a Source of Color
It is possible to color grout by blending artist acrylic paint with white grout, and acrylic paint can improve the strength of the grout, but it is not recommended for aesthetic reasons. Why not? In most mosaic art, the grout line functions visually the same way as a pencil line functions in a watercolor painting: it is a linear element that acts as a border and defines shapes but not as a source of color. Mosaics that rely on grout as a source of color usually look ill-conceived or not quite right. If you are trying to make something that looks like objects pressed in concrete, make sure the concrete looks like concrete and not pink plastic.
There are mosaics where white grout is the best choice, but they are few and far between. White grout makes most mosaics look like a summer camp project, and that probably isn’t the look you are going for in your project. If you want a light grout, choose bone white (antique white or eggshell white). Binding white grout can flatten most tile colors. In general, darker grouts usually make the tile colors look deeper and richer while white grout tends to make tile colors look bleached out. When in doubt, avoid plain white grout.
How Much Grout Do You Need?
How Much Grout Do You Need? It depends as much on the gaps between the tiles as it does the total area. If your gaps are the standard 1/16 inch, and you are using thin glass mosaic tile, then you will probably use less than 1 lb of grout per square foot. If you have thick tile with large gaps, you could use over 1.5 lb.
However, waste is a significant factor, and you have to budget extra for all the grout you will have falling off the sides of the mosaic when you smear it on. We recommend grouting over a plastic dishpan so you can catch the droppings and pick them back up. For first attempts at grouting, you should be conservative budget some extra for waste. Remember, a little wasted grout is better than a wasted mosaic!
Grouting outdoors is best, especially some place you can run a water hose and don’t mind a little sand and residue being rinsed. Excess grout could kill grass or plants, so scoop up what you can and dispose of it as solid waste and wash away what is left with plenty of water.
Grout and concrete harden by BINDING water not by drying out. If you let grout or concrete dry out while it is curing, then it will be soft and crumbly. This also happens if you did not add enough water to the grout when you mixed it up. Cover your mosaic with plastic if you are grouting in strong heat, sunlight, air conditioning, wind or any other condition that accelerates drying.
Make sure you rinse all the water out of your sponge so that it is moist but not leaving drips of water when you rub it on the mosaic. You do not want to get drips of water in the grout in the gaps when you are rubbing the residue off the faces of the tile.
Do not pour left over grout or grout sludge down plumbing or drains. Grout is concrete and can harden under water. Even sand can clog drains. Instead, pour your grout and grout water into an old plastic container. After it hardens, you can pour off the water and dispose what is left as solid waste.
We use traditional grouts and NOT the new epoxy-grouts, and all our advice is written for traditional grout. If you use the new epoxy-base products, then make sure you read manufacturer recommendations for safety and disposal.
Always wear safety glasses with side shields when mixing and applying grout. Grouting is a physical process with lots of mixing and rubbing and wiping, and these motions cause pieces of sand and grit to fly unexpectedly.
Grout contains powdered silica (sand) and is slightly caustic due to the lime it contains. Avoid breathing the dust. Use a dust mask when mixing or use a misting water bottle to avoid creating dust.
Grout can also irritate the skin, sometimes severely if you have sensitive skin. The sand and rubbing required in grouting further aggravate this problem. Wear heavy-duty rubber grouting gloves while grouting to protect your skin, but be aware that sharp edges can cut through the gloves and avoid pressing fingers down into wide grout gaps.
How To Make Mosaics
For more advice on designing your mosaic project or mounting, cutting, and grouting tile, please see our page of Mosaic Frequently Asked Questions or our Mosaic Information Guide, which lists instructional pages described by topic. We also post new articles about making mosaics at our How to Mosaic Blog.