Knowing how much tile adhesive you’ll need on a project is just as important as knowing how many tiles you’ll need. Buy too much of either, and you’ll be left with a pile of tiles and tile adhesive that will soon be out of date and of no use.
At the other end of the scale, if you buy too little, you’ll run out before you finish tiling a wall or floor. This means another visit to your point of purchase, which will hold up your tiling project. The simple answer is to accurately estimate before you get started. And you can with the help of this guide.
Shop these tiling tools and products
Crafted from high-quality stainless steel for smooth and clean application. Its 10mm notches make it an ideal choice for floor tiles where the adhesive needs larger gaps.
Specifically tailored for stone, porcelain, and ceramic tile. This grey adhesive is a rapid-set and formulated for wet and dry conditions and adheres to common substrates.
A white, easy-to-mix cement-based powdered grouting compound designed for wall tiles. It can be used on joints up to 3mm and is suitable for use in kitchens, bathrooms and showers.
Stephen is an independent tiler with other 30 years in the industry. He specialises in kitchen tiling, walls and floors and general tiling repairs.
Factors affecting how much tile adhesive to use
It's not as simple as you think; there are a host of factors to consider when working out how much tile adhesive is needed for a job. Stephen Russell, Tiler at Ashley Cross Tiling, shares a simple rule, “First, are you laying wall or floor tiles? As a general rule, you will need less adhesive for wall tiles than you will for floor tiles.”
Article continues belowHe adds, “The size of the tile will determine how much tile adhesive is needed, too. The larger the tile, the more adhesive will be needed to hold it in place.”
Then you will need to consider what the tile is made of, i.e. porcelain vs ceramic. Harriet Goodacre, interiors and tiling expert at Topps Tiles, says, “Porcelain tiles are denser and less porous than ceramic, so they typically require a flexible adhesive with a stronger bond.”
She adds, “Natural stone may also require a specific adhesive, particularly if it’s moisture sensitive.”
What type of adhesive – powder or ready mixed – will make a difference. Russell says, “Ready mixed is only good for internal walls, so that means you need less. If tiling a floor, powder adhesive is the recommended choice, and you will need more as you will typically need a greater depth.”
To a lesser extent, the spacing you choose will make a difference. If using 2mm rather than 3mm or 5mm spacers, you will use slightly less adhesive. Obviously, the larger the area being tiled, the more tile adhesive will be needed.
If ever unsure about how much tile adhesive you need, check the packaging. This will give you a good indicator of how much the bag/container will cover. And a general rule that if in doubt, buy more than you need.
Also, make sure that you have the best tiling tools to apply the adhesive. This is especially true when picking a tiling trowel. A standard 10mm notched trowel is good for walls, while you typically need a floor trowel for laying floor tile adhesive.
Harriet is a tile and interiors expert at Topps Tiles, with over a decade at the brand and more than 15 years’ experience working with home and lifestyle brands. She specialises in all things tiles and tile design, including layouts, colour pairings and interiors trends, offering practical and stylish guidance for real homes.
How much a 20kg bag of tile adhesive will cover
If tiling a wall, expect to use around 2-3kg per m2. This means you will be able to cover an area of around 6-10m2 with 20kg of tile adhesive. This will be enough to tile the bathroom from the bath to the ceiling.
If you are tiling a floor, you will need more adhesive per square metre. Expect to use around 4-6kg per m2, meaning 20kg will cover 3 to 5 m2.
Ready-mixed tiling adhesive is typically more expensive than powder adhesive. But it is more convenient, while powder is good for both walls and floors. You can get 20kg of powder adhesive, such as Mapei Rapid Set Wall & Floor adhesive, for around 20-40% less than a ready-mixed solution.
Powder vs ready-mixed tile adhesive
This depends on what you are tiling, floor or wall. Russell says, “As a general rule, ready mixed is good for walls and is easier to use than powder adhesive. There’s no mixing involved, and you can get straight to tiling, but it typically takes longer to dry.”
He adds, “Look for a waterproof adhesive if tiling a bathroom.” If laying floor tiles, it is recommended to use powder adhesive, as it dries differently from ready-mixed adhesive and is better suited to areas with moisture, i.e. bathrooms.
How thick should tile adhesive be?
As a general guideline, you need around 1-3mm of tile adhesive for most wall tiles. Typically, wall tiles require less adhesive than floor tiles because they endure less stress. However, if you are installing large wall tiles, you will typically need more adhesive to hold them in place.
Goodacre says, “The goal is to achieve full and even coverage once the tile has been pressed firmly into place.” However, this can be different for different types of tiles, continues Goodacre, “Some rustic or smaller-format ceramic wall tiles can have uneven backs as part of their character. In these cases, the adhesive depth may need to be adjusted to ensure the tiles sit level and flush with one another.”
The depth for floor tiles is different, shares Goodacre, “Floor tiles also typically require greater coverage than wall tiles because they need to withstand heavier loads. For floors, you should aim for close to 100% adhesive coverage.”
She adds, “The key is selecting the right adhesive and trowel size for the tile type and ensuring proper coverage, rather than working to a fixed thickness.”
But again, it depends on the tile's size. When looking at bathroom floor tile ideas, you might go for a standard size or opt for large tiles. As you might expect, larger tiles typically require more adhesive to stay in place. They are generally heavier, meaning that they compress the adhesive more.
FAQ
Do you put tile adhesive on the tile or wall?
Tilers work in different ways; some apply adhesive directly to the wall, while others apply it directly to the tile. Putting adhesive on the wall is common practice as this gives a more even layer.
This is also a good choice if you are tiling around a window. You can pre-cut the tiles and apply the adhesive, so you aren’t in awkward-to-reach areas for as long.
But some experienced tilers prefer to put adhesive directly on the tile. This allows for just the right amount for each tile, the back of the tile needs to be covered with adhesive to get a strong, secure finish. This option takes a bit more practice to get right, so it may not be the best route for the DIYer.
Both options work perfectly well – when done properly – but for those new to tiling, putting adhesive on the wall is the easier option. Just make sure to do a few practice runs.
If you want a good deal on tiles, check our where to buy bathroom tiles. To decide which tiles you want, take a look at our kitchen floor tile ideas and bathroom tile ideas for small bathrooms for inspiration.
