Grout is often overlooked until problems become serious — discolouration, crumbling, cracking and mould growth. Whether you need grout repair or full regrouting depends on the extent of the problem, the type of grout and the underlying cause of the damage.
Why Does Grout Fail?
- Movement — tiles and substrates expand and contract with temperature and humidity, putting stress on grout lines that are too rigid
- Moisture penetration — water behind tiles degrades the substrate and causes tiles and grout to crack or loosen
- Cleaning products — acidic cleaners etch grout surfaces and cause deterioration over time
- Age — cement-based grout (the most common type in UK bathrooms and kitchens) typically lasts 10–15 years before it begins to deteriorate
- Poor original installation — incorrectly mixed or applied grout fails faster
Types of Grout Problems
- Discolouration — grey or stained grout that cleaning cannot restore
- Crumbling — grout that is breaking down and coming loose
- Cracking — hairline or wider cracks in grout lines
- Mould — black mould that surface treatment cannot fully remove
- Missing grout — sections where grout has completely fallen out
Grout Colouring and Sealing
For grout that is structurally sound but badly discoloured, grout colourant products can restore the appearance without full regrouting. A grout colourant penetrates and recolours the surface, making grout look fresh and new. This is combined with a grout sealer to protect against future staining and moisture penetration.
When Full Regrouting Is Needed
Full regrouting — removing all existing grout and replacing it — is needed when:
- Grout is crumbling or cracking across a large area
- There is evidence of movement or water ingress behind tiles
- Mould has penetrated the grout and cannot be removed
- You are changing tile colour or layout
Movement Joints and Silicone
An important grout-related repair that is often missed: the silicone sealant at internal corners (where the wall meets the floor, where two walls meet) should never be replaced with rigid grout. Silicone is used at these joints specifically because it accommodates movement that would crack rigid grout. Replacing failed silicone at corners is often more important than addressing the grout itself.
Get Professional Grout Advice
If you’re unsure whether your grout needs cleaning, colouring, resealing or full replacement, contact us with photographs and we’ll advise on the most cost-effective approach.
