Shower regrouting and sealing

A professional regrout and reseal doesn't just prevent leaks; it also transforms the appearance of your bathroom. By removing discoloured, mouldy joints and replacing them with fresh, anti-microbial materials, you can achieve a "like-new" finish without the expense of a full retiling project.

What Does the Work Involve?

• Inspection: Assessing the stability of the tiles and checking for signs of underlying water damage or "blown" plaster.
• Raking Out: Using manual or oscillating tools to remove the top layer of old, damaged grout without chipping the tile edges.
• Sealant Removal: Carefully stripping away old silicone from the shower tray, bath, and corners using specialist blades and chemical removers.
• Sanitisation: Deep cleaning the exposed joints with fungicidal washes to kill mould spores and ensure a sterile surface for the new materials.
• Regrouting: Applying fresh, water-resistant grout (cement-based or epoxy) and sponging off the excess for a smooth, consistent finish.
• Siliconing: Applying a neat bead of high-quality, sanitary-grade silicone to all internal corners and perimeters to allow for movement.

Typical Costs

Prices are influenced primarily by the size of the tiles—smaller mosaic tiles require significantly more labour to rake and grout than large-format tiles. Regional variations also apply, with London and South East rates typically sitting 20% higher than the UK average.

How Long Does It Take?

• Sealant replacement only: 1 to 2 hours.
• Standard shower regrout: 4 to 6 hours (usually completed in one day).
• Large walk-in wet room: 1 to 2 days depending on tile size.
• Curing time: 24 to 48 hours before the shower can be used (crucial for the sealant to set).

DIY or Professional?

While DIY kits are available, achieving a professional, watertight finish is harder than it looks. Raking out grout carries a high risk of scratching or cracking expensive tiles, and applying a perfectly smooth silicone bead requires significant practice.

Professional surface repair specialists use industrial-grade anti-mould products and epoxy grouts that are far more durable than standard DIY store alternatives.

For rental properties, a professional receipt provides proof of maintenance, which is vital for insurance claims or deposit disputes. If the work involves removing taps or shower valves, ensure the specialist is comfortable with basic plumbing or hire a plumber to assist.

Choosing the Right Tradesperson

• Look for specialists in "Surface Repair," "Mould Remediation," or experienced Tilers.
• Check for Public Liability Insurance (minimum £1m) to cover accidental damage to your bathroom suite.
• Ask if they offer a guarantee against leaks or mould regrowth (typically 12 months).
• Questions to ask:
  • Do you use anti-fungal grout and sanitary-grade silicone?
  • Will you remove all the old grout or just "skim" over the top?
  • Is the waste disposal included in your quote?
  • How long must I wait before using the shower?

UK Regulations

While regrouting is considered "like-for-like" maintenance and does not require Building Regulations approval, there are standards to consider:

• Landlord Obligations: Under the Homes (Fitness for Human Habitation) Act, landlords must ensure bathrooms are free from damp and mould caused by failed seals.
• British Standards (BS 5385): This code of practice covers the design and installation of wall and floor tiling, including the use of water-resistant grouts in "wet areas."
• Waste Disposal: Professional trades should have a Waste Carrier Licence if they are removing significant amounts of debris from your property.

Common Problems

• Grouting over old grout: A common "cowboy" tactic where a thin layer is applied over the old. This will peel off within weeks as it cannot bond properly.
• Poor Silicone Adhesion: If the surface isn't 100% dry and free of old silicone residue, the new bead will pull away, leading to immediate leaks.
• Chipped Tiles: Using the wrong power tools to remove grout can permanently damage the glaze on your tiles.
• Inadequate Curing: Using the shower too soon is the number one cause of failed repairs; the sealant must be bone dry to form a bond.

Frequently Asked Questions

Can I just put new silicone over the old mouldy sealant?

No. New silicone will not stick to old silicone, and you will simply trap the mould underneath where it will continue to grow and rot the substrate. All old sealant must be mechanically and chemically removed first.

How often should a shower be regrouted and sealed?

In a typical UK household, silicone sealant should be replaced every 2-3 years. Grout usually lasts 10-15 years, but may need "refreshing" sooner if the bathroom has poor ventilation.

What is the difference between Epoxy and Cement grout?

Cement grout is cheaper and easier to apply but is porous. Epoxy grout is made from resins and filler, making it completely waterproof, stain-resistant, and much harder to scrub away, though it is more expensive to install.

Why does my new grout have white patches or "efflorescence"?

This is usually caused by using too much water during the cleaning process or salts in the water supply. A professional will use the correct water-to-powder ratio and distilled water if necessary to prevent this.

Can regrouting fix a leak into the room below?

If the leak is caused by water seeping through cracked grout or failed silicone, yes. However, if the leak is coming from a burst pipe behind the wall or a faulty waste trap, regrouting will only hide the problem temporarily.