How to remove old silicone from tiles, a bath or glass

What you need

• Utility knife or thin blade with new blades
• Plastic spatula or silicone scraper
• Glass scraper with a new metal blade (only for glass and tile)
• Small pliers
• Nitrile gloves
• Microfibre cloths
• Masking tape
• Silicone remover from makes such as Soudal or Würth, from Leroy Merlin or a ferretería (hardware shop)
• Isopropyl alcohol or 96% alcohol
• Kitchen paper
• New anti-mould sanitary silicone: Sika, Pattex Baño Sano or Ceys
• Water with neutral soap for smoothing the new bead

Step by step

1. 1

   Identify the surface

   Look at what surrounds the silicone: glazed tile, enamelled steel or acrylic bath, resin tray, glass or aluminium. The surface decides the tool. Plastic, acrylic or resin surfaces are scratched by metal.

2. 2

   Ventilate and protect yourself

   Open the window and put on gloves. Silicone remover has a strong smell and can irritate the skin. Protect the floor with paper or plastic: bits of silicone are slippery.

3. 3

   Cut the silicone along both edges

   With the blade at a low angle, run along the edge of the silicone next to the tile and then the edge next to the bath or screen. Do not press towards the surface: rest the blade on the silicone. On acrylic and resin, use a plastic spatula instead.

4. 4

   Pull off the strip

   Grip one end with pliers or your fingers and pull the bead away slowly. If the silicone is recent, it often comes out whole. If it breaks, repeat the cut and carry on in sections.

5. 5

   Apply the silicone remover

   Spread the remover over the residue with a brush or spatula. Cover with a piece of cling film so it does not dry out. Respect the time on the pack, normally between 30 minutes and several hours. The thicker the layer, the longer it takes.

6. 6

   Scrape off the residue

   With the plastic spatula, push off the softened residue. On tile and glass you can use a new, flat blade at a low angle. On aluminium joints and screen profiles, work the spatula carefully.

7. 7

   Rub away the remaining film

   Even if you cannot see it, a thin film of silicone is left. Rub it with a cloth soaked in isopropyl alcohol until it leaves no marks. If a haze remains, repeat with remover. New silicone will not stick if there is a film.

8. 8

   Clean and degrease

   Wipe with a cloth, water and neutral soap, rinse and degrease with alcohol. Remove any trace of mould or soap; if there is mould, treat it first as we explain in how to remove mould from the shower.

9. 9

   Leave to dry for 24 hours

   This is the part most often forgotten. The joint must be completely dry inside, especially if the old silicone had mould or water had got behind. With a gentle hairdryer and ventilation, the time shortens, but do not skip it.

10. 10

    Tape up and reseal

    Stick masking tape on both sides of the joint, run a continuous bead of anti-mould sanitary silicone, smooth it with a finger wetted in soapy water and remove the tape before it skins over. The step by step is in how to seal a shower screen.

Which silicone you have and which tool to use on each surface

In the bathroom almost all silicone is sanitary (acetic) and sticks firmly to enamel, glass and aluminium. It comes away well with a blade if you cut it right against the edge, but leaves a thin film that only goes with remover or alcohol. In older work you may find neutral silicone of other makes, which gives a little more easily.

What matters is the surface, because it decides what you can scrape with. Glass and glazed tile will take a new blade. An enamelled steel bath will too, with care. But acrylic, resin and lacquered profiles are scratched by metal, and there only plastic will do.

How to remove silicone from tiles, a bath and glass step by step

On tiles, the key is to cut right against the edge of the silicone, without touching the cement grout. If the grout is porous and blackened, treat it first with hydrogen peroxide. Once you have taken the silicone off, check that no damp remains in the gap, because that is where mould lives.

On the bath, tell the material apart. An enamelled steel bath takes a blade with care; an acrylic one or a resin tray, plastic only. If the surface marks with your fingernail, it is plastic. On shower screen glass, the scraper blade must be new and flat, at a very low angle, and always along the line of the silicone, never sideways. On the edges of toughened glass, avoid pressure.

For the aluminium of screen profiles, use only a plastic spatula. If you are also replacing the screen seals, the step by step is in how to replace shower screen seals.

Common mistakes when removing silicone

• Putting new silicone over the old. It does not stick: it peels within weeks and traps damp.
• Scraping acrylic or resin with a blade. It leaves permanent scratches that fill with limescale and soap.
• Using acetone or aggressive solvents. They damage plastics, rubber seals and some resins.
• Not degreasing with alcohol. A film of silicone remains and the new joint does not stick.
• Not waiting for it to dry. Sealing over damp traps the water and mould reappears under the new silicone.
• Removing the silicone with no tape or plan. Making the new joint without masking tape leaves ugly edges that force you to redo it.

When to call a professional

Removing silicone is simple, but slow. If the screen is toughened glass with delicate edges, if there is silicone in many joints (tray, bath and walls) or if there is mould or damp behind, it is best done by someone with the right tools. Also if the joint has cracked because the tray has moved: there the problem is not the silicone.

At Manitas Costa, resealing with silicone costs €40-70, removing an old shower screen €50-65 and replacing the seals or rollers €45-80. If the tile grout has to be redone too, replacing 1-5 tiles costs €60-120 and regrouting a whole bathroom €150-300. We give a fixed price before we start, with an invoice including IVA (VAT) and a six-month written guarantee.

More detail in shower screens and sealing and shower screen prices. For specific areas, shower screens in Alicante and shower screens in Valencia. If the underlying problem is a dirty tray, there is how to clean a resin shower tray.

Damp and heat: sealing properly on the coast

In Torrevieja, Benidorm, Alicante or Valencia the humid air slows drying and encourages mould under the new silicone. Dry the gap with a cloth and cross ventilation the day before, and do not seal if it has rained or the bathroom is still damp. In summer, with temperatures of 30-35 °C, silicone skins over in minutes: work in the coolest hours, section by section.

In holiday lets, silicone suffers from constant use. Check the sealing every year before the season and renew it every four. Choose anti-mould sanitary silicone from makes such as Sika, Pattex Baño Sano or Ceys. And if you see black spots, first look at how to clean limescale off a shower screen so you do not confuse mould with limescale.