The three failure patterns and what they mean
Uniform surface staining and mould on the silicone only: cosmetic. A strip-out and reseal, plus better ventilation, solves it.
Cracking along one straight line, usually where wall meets tray or floor: movement. That joint should have been flexible silicone, not rigid grout. Correct joint, correct material, done.
Random cracking with hollow-sounding tiles: the adhesive bed has failed or the substrate is moving. Regrouting here is decoration over a structural problem.
How we regrout properly
Rake out to at least two-thirds of the tile depth - surface skimming is what makes cheap regrouts fail within a year.
Vacuum and dry the joints, then apply a cement-based grout suited to the joint width, followed by flexible silicone at every internal corner and change of plane.
Where the room is poorly ventilated we recommend an anti-mould sealant and an extractor upgrade at the same time, otherwise you will be back here in eighteen months.
When we will tell you not to bother
If more than a handful of tiles sound hollow, or the wall behind is soft, regrouting is money spent twice. We would rather say that at survey than take the job.
Frequently asked questions
How much does regrouting a shower cost?
It depends on the tiled area and how much silicone has to come out. We quote fixed price after seeing it, and we will tell you honestly if it is not worth doing.
Why does my silicone keep going black?
Almost always ventilation. Mould grows in the film of moisture left on cold surfaces; an extractor that actually runs on for a few minutes after use is the single biggest fix.
Can you match my existing grout colour?
Usually close, though aged grout has faded. On a partial regrout we will show you the nearest match before committing.
Is epoxy grout worth it?
In heavy-use showers and on floors, often yes - it is far more stain resistant. It costs more to buy and to fit because it is unforgiving to work with.
Next step
Not sure if yours is cosmetic or structural? We will tell you straight at the free survey.
Free quote • No pressure • Fast response