How to Tell Good Tiling from Bad Tiling
What to look for when checking tiling work in a bathroom or kitchen. The visible signs of quality installation and the warning signs that problems are already forming.
Most people cannot tell good tiling from adequate tiling at a glance, and this is understandable. But there are things to look for that tell you quite quickly whether a job has been done properly or whether problems are forming under the surface.
This guide is useful whether you are inspecting a bathroom before buying a house, checking recently completed work, or trying to understand what separates a quality installation from a cheap one.
What your eye should check first
Grout lines
Stand back and look at the grout lines across the tiled surface. They should be consistent in width, run in straight lines, and not wander. If the lines converge, if they vary in width, or if they are visibly uneven in a regular tile field, the setting out was not done correctly.
In a well-tiled room the grout lines continue through from one wall to another, align at internal corners, and look intentional. Grout lines that appear to have been managed at the last moment, with cuts getting smaller towards one edge of the room, suggest the tiler started from the wrong point.
The cuts at the edges and corners
Look at the tile cuts at the edges of the room, at the bath edge, around the shower tray, and at internal and external corners. The cuts should be consistent and reasonably even on both sides of the room.
Half a tile on one side and a sliver on the other suggests the layout was not set out from a central datum before tiling began. This is the most common sign of inexperienced setting out on a domestic bathroom job.
External corners
External corners, where two tile faces meet at a projecting angle, are a point of detail. They should be finished cleanly, either with a mitre joint, a metal edge trim, or a correctly fitted corner trim. Rough cuts at external corners, or corners where the tiles simply end without a finish, indicate a lack of care.
The silicone joints
The joint between tiles and any sanitary ware, bath, shower tray, or at the floor-to-wall junction should be silicone, not grout. Silicone is flexible and accommodates movement. Grout is rigid and will crack at these junctions within months.
Look at the bath edge, the shower tray joint, and the floor junction. If they have been grouted, or if the silicone has been applied so thickly or unevenly that it looks like it was added as an afterthought, this is a warning sign.
Properly applied silicone is neat, consistent in width, and tooled smooth. It is not a difficult detail but it is one that is often rushed.
What you cannot see: the bigger risks
The most significant problems in a tiled bathroom or kitchen floor are not visible to the eye. They are in what was done before the tiles went on.
Adhesive coverage. A tile should have full or near-full adhesive contact on its back. In practice, a tiler in a hurry applies a notched trowel to the substrate and presses the tile on without back-buttering. The result is 40 to 60 percent coverage and voids under the tile. These voids cause tiles to crack under impact, allow moisture to pool under the tile, and cause the tile to sound hollow. Hollow-sounding tiles are a reliable sign of inadequate coverage.
Waterproofing in wet areas. A wet room or shower area that has not been tanked properly will allow water to penetrate the substrate and cause damp, rot, and structural damage over time. You will not see this for months or years after installation. By the time it is visible, the remedial work is significant. This is covered in more detail in the what is tanking guide.
Expansion joints. Tiled floors without expansion joints at perimeters and intermediate points will crack as the tiles expand and contract with temperature and use. The cracks typically appear at grout lines and at the perimeter. If a floor has no flexible silicone joints at the skirting board level, they were omitted.
What to ask a tiler when getting quotes
A few questions that tell you whether the person quoting understands the work:
- How do you prepare the substrate in this type of bathroom?
- What adhesive will you use and what is the classification?
- Where will the silicone joints be, and what will be grouted?
- For a wet room: what tanking system will you use?
The answers matter less than the confidence and specificity with which they are given. Someone who has been doing this correctly for years will answer without hesitation. Someone who has not will give vague or incomplete answers.
I have been tiling since 1982. The work I do in Bromley, Beckenham, Chislehurst, Orpington, and across South East London is built on exactly the things described above: proper setting out, correct adhesive, full coverage, movement joints, and waterproofing that will still be working in ten years.
If you want to see more about what is involved in a well-specified installation, the about page has more background, or call me directly.
Related reading: Why tiles crack and what it means · What is tanking? · How much does bathroom tiling cost in London? · Bathroom tiling service
Got a specific question? Call me on 07990 521717 , see the bathroom tiling service, or use the contact form — I'm happy to give advice with no obligation.