How many bags do I need? You know that feeling: you’re in the middle of the store aisle with a bag of grout in your hand, panicking because…will there be enough? You’ve picked out the color and you’ve measured the floor. Now all that’s left to do is figure out how much you’ll need to cover the area, but those numbers on the box of grout aren’t making any sense.
Grout coverage isn’t an exact figure. It depend on the width of joints and size of tiles. Knowing this relationship will prevent you from over-buying or storing hard, cement-like grout.
How Much Grout Do You Need?
How much grout you’ll get from a bag depends on how wide your joints are. It’s something that DIYers forget about. The more space between tiles, the more material there is to fill. Depending on joint width, a bag may stretch over two hundred square feet if your joints are thin, or half as much if they’re wide. It’s a matter of geometry, and can result in emergency trips to the store.
Do I use sanded or unsanded grout? That comes down to joint width. Unsanded has no sand; it’s smooth and made for joints smaller than an eighth of an inch. It is good for polished marble, glass mosaics, etc., because it doesn’t scratch those more delicate finishes.
Sanded grout include a small amount of fine sand that helps fill out the joint and won’t shrink quite as much. It is good for big slab work like floors, where you want something sturdy. The wrong one will crack so check what spacers you are using before going forward.
Coverage efficiency can be affected by tile size as well. More grout is used when there are more joints per square foot and larger tiles will have fewer joints. For example, twenty-four by twenty-four tiles will require less product than small two by two mosaics. Even though both options may have a similar joint width, the math work in favor of larger format. Large format installations uses less grout and are more economical.
Estimate how much you’ll need, taking into account entire space (including that extra 10 percent buffer for waste. For cuts, spills and other unevenness in surface). You also want to purchase all of your bags from one dye lot, otherwise the color won’t be consistent. Once cured, a slight variation in shade from batch to batch will realy stand out.
Even if the math shows you only need half a bag, round up to the next full bag. Having just enough or too little is far more annoying than having leftover grout. You should of bought extra.
A good tool goes a long way. The right angle on your grout float minimizes wasted product and so do proper calculations. Careful application won’t extend life of the bag if you’ve miscalculated the size of the joint.
Conservatism is key. It’s a bit of an art and math equation to figure out tiling. Art is the pattern, and math is the coverage chart that makes project work. Once you grasp what happens when you mix tile size with joint width with grout type, the guesswork goes away. It transitions from guess to plan. Knowing exactly how much material you have makes it possible. It’s worth having that peace of mind before you start.
