Causes of Loose Tiles and the Right Solution
Causes of loose tiles - and how to identify them
Loose tiles or voids under tiles are a widespread problem in bathrooms, kitchens, and other tiled rooms. Loose tiles, often referred to as tiles with insufficient adhesion in condition reports, occur when the connection between the tile and the substrate fails. This causes an air pocket or void to form behind the tile, meaning the tile's connection is no longer stable.
A typical sign is a hollow sound when you tap on the tile, which can indicate tiles with voids.
What causes a tile to become loose
Loose tiles are almost always due to the adhesive connection losing its ability to hold the tile firmly against the substrate, and there are several reasons for loose tiles:
Insufficient adhesion is often due to conditions during the laying of the tiles. In some cases, it can be due to moisture in the foundation, especially in newer houses. It is also seen that underfloor heating is turned on too early in the construction process, which can affect the curing of the adhesive and weaken the connection between the tile and the substrate.
Moisture and water penetration Water penetrating through fine cracks in the grout breaks down the tile adhesive used over time in bathrooms, especially in wet rooms and kitchens. Outdoors, frost periods can expand the water and create voids under fixed tiles.
Substrate movement Concrete slabs and lightweight concrete walls move minimally due to temperature fluctuations and building settlement. If the tiles are laid without sufficient expansion joints, the movement is transferred directly to the adhesive bond, which cracks or detaches.
Adhesive that has dried out or lost its elasticity Tiles laid 10–20 years ago are typically held by a tile adhesive that is no longer able to absorb the minor movements a house naturally makes.
How to recognize tiles that have a void
If you tap lightly with your knuckles or the handle of a screwdriver on a tile, and it sounds hollow or metallic rather than solid and muffled, there is a void behind the tile. This method is called a tap test – in technical terms, one speaks of "hollow-sounding tiles," and the sound resembles a hollow thud.
This is the reliable method for locating loose tiles before they show visible signs. Early intervention can prevent the problem from spreading to more tiles or the substrate.
Two ways to repair
Traditionally, repairing loose tiles in the home involves carefully removing the tile, cleaning off the old tile adhesive, and installing the tile or a new one – with fresh adhesive. The method is thorough and ensures a stable result, but it requires both time and patience. Often, it is also a bigger task to find a new or similar tile, especially if the tile has been discontinued or is older. If the tile is broken, or the substrate has been damaged, this solution is necessary to achieve a durable repair.
If the tile, however, is intact and the substrate is sound, there is a much gentler method: injection adhesive. Here, a small hole of 2–3 mm is drilled into the grout close to where the tile feels hollow - not in the tile surface itself - and ADIN Injection Adhesive is injected into the void behind the tile. The adhesive then fills the void and re-establishes the connection to the substrate. The tile can be walked on 30 minutes after injection.
ADIN glue is a patented injection technique developed specifically for this purpose. The product is intended for both professional tile setters, craftsmen, and DIY enthusiasts, and requires no prior knowledge.
When is ADIN injection adhesive the right solution?
The ADIN Injection Adhesive method is suitable when there is a void under the tile. The tile must be whole and without visible damage, and the substrate must also be stable and dry.
The method makes it possible to preserve existing tiles and avoid major interventions with replacement.
Injection adhesive is a good solution in situations where there are no signs of moisture damage, and where the tile surface and grout are intact. The method is suitable for both floor and wall tiles, even in areas with underfloor heating, as the adhesive remains elastic and can follow the natural movements of the substrate.
If, on the other hand, there is a substrate with moisture damage, cracked tiles, or large bumps, it is necessary to break up and repair the substrate before new tiles are laid.
Injection adhesive should not be used if there is suspicion of mold, rot, or extensive moisture problems behind the tiles. In these cases, a thorough investigation and possibly a traditional repair is the best solution.
Order here
Do you have loose or hollow-sounding tiles and want to repair them without replacing your tiles? Order ADIN directly in the shop at adinglue.dk or call Benjamin at 2721 9954. We will help you find the right approach for your specific situation.
FAQ - Frequently asked questions about the causes of loose tiles
Can one loose tile indicate that more are loose? Yes, a single loose tile can often indicate that more tiles in the area have also lost their connection to the substrate. Moisture, substrate movement, or aging of the adhesive rarely affect only one tile. It is therefore recommended to examine neighboring tiles by tapping lightly on them and checking a larger area before choosing to repair.
When is injection adhesive the right solution for loose tiles? Injection adhesive works best when the tile is intact, the substrate is stable and dry, and the cause is adhesive failure or air pocket formation. See our videos with instructions on using ADIN.
Can you use injection adhesive for loose tiles yourself? Yes. ADIN glue is developed for both professionals and DIY enthusiasts. In addition to ADIN injection adhesive and the patented injection needle, it only requires a regular drill with a 2–3 mm drill bit and a caulking gun. Please note that in wet rooms and wet zones, the grout may feel extra hard due to water exposure. 24 hours after injection, the injection hole can be filled with tile grout. See our videos with instructions on using ADIN.
How long does it take to repair a loose tile with injection adhesive? The injection itself typically takes 20–30 minutes per tile, depending on the size of the air pocket. The tile can be walked on 30 minutes after repair.
Does injection adhesive work on all tile types? ADIN injection adhesive is suitable for ceramic tiles, clinker, and natural stone, provided the substrate is stable. Contact us if you are unsure whether the method is suitable for your situation.