Grouts and silicones for tiling projects
This range covers grout and silicone sealant products from Roberts Designs, the two main jointing and sealing materials used to finish a tiling job. Grout fills the gaps between tiles across a flat surface, while silicone is used at specific junctions, corners and wet-area perimeters where a flexible, movement-tolerant seal is needed instead of a rigid one. Anyone tiling or retiling a bathroom, kitchen splashback, laundry or outdoor area will generally need both products, used in the correct locations, to get a finished result that holds up over time.
What grout does
Grout is applied between tiles to fill the gap left during installation, locking the tiles in place and closing the surface so water and dirt cannot get underneath. It is a rigid material once cured, which makes it suitable for flat tiled surfaces like floors and walls, but not suitable for joints that need to flex or move, such as where a wall meets a floor or where a bath meets a tiled surround.
What silicone does
Silicone sealant is used at movement joints and wet-area junctions, places like internal corners, the joint between a tiled wall and floor, around a bath, shower base or benchtop, and anywhere two different surfaces meet. These points experience small amounts of movement over time due to temperature change, building settlement or general use, and a rigid grout joint in these locations is more likely to crack, whereas silicone remains flexible and continues to seal the gap.
Colour matching to your tiles
Grout and silicone are both available in a range of colours, and matching the colour to the tile choice is one of the more visible decisions in a tiling job, since grout lines run across the entire tiled surface and silicone beads sit at obvious junctions like internal corners. Selecting matching or complementary colours for both products, rather than treating them as an afterthought, helps the finished job look intentional rather than mismatched.
Sanded versus unsanded grout
Grout is generally available in sanded and unsanded formulations, and the right choice depends on the width of the gap between tiles. Wider gaps typically call for a sanded grout, which resists shrinking and cracking across a larger joint, while narrower gaps are more commonly filled with an unsanded grout. Checking the tile manufacturer's recommended gap width, and matching the grout type to that gap, helps avoid cracking or shrinkage after the job is finished.
- Grout fills flat gaps between tiles on floors and walls
- Silicone seals movement joints and wet-area junctions such as corners and bath edges
- Match grout and silicone colour to the tile choice for a consistent finish
- Choose sanded or unsanded grout based on the width of the tile gap
Confirm gap width and joint location before choosing between grout and silicone, since using the wrong product in a movement joint is a common cause of cracking.
Frequently Asked Questions
What is the difference between grout and silicone?
Grout is a rigid material used to fill the flat gaps between tiles on a floor or wall, while silicone is a flexible sealant used at movement joints and wet-area junctions such as internal corners or where a bath meets tiling. Grout is not designed to flex, so it should not be used in joints that experience movement.
Where should I use silicone instead of grout?
Silicone should be used at movement joints and wet-area perimeters, including internal corners, where a tiled wall meets the floor, around a bath or shower base, and anywhere two different surfaces meet. Using grout in these spots instead of silicone is a common reason cracking appears after a tiling job is finished.
Should grout match the colour of my tiles?
Matching or complementary grout colour is worth choosing deliberately, since grout lines run across the entire tiled surface and are highly visible. Silicone should also be selected in a matching colour, particularly at corners and edges where it sits alongside the grout.
What is the difference between sanded and unsanded grout?
Sanded grout is generally used for wider gaps between tiles, as it resists shrinking and cracking across a larger joint, while unsanded grout suits narrower gaps. Checking the tile manufacturer's recommended gap width is the best way to choose between the two.
Can I use the same silicone for both indoor and outdoor tiling?
Silicone products can vary in what conditions they are designed for, so it is worth checking that the specific product is suited to the location, particularly for outdoor or heavily wet areas. Matching the product to the joint location and exposure conditions helps the seal last as intended.
