Which Silicone for a Frameless Shower Screen, and When Can You Shower?

Silicone is the least exciting part of a shower screen and one of the most important. It's what stops water tracking under your glass and into places it shouldn't be. Pick the wrong type, and it can go mouldy, fail early or even damage your hardware.

Neutral cure vs acetic cure

There are two main families of silicone sealant.

Acetic cure gives off a vinegar smell as it cures. It's cheap and cures fast. But Sika's technical data warns that the acetic acid "can cause the corrosion of mirror silver and sensitive metals such as copper, brass and lead", and that acetic sealants aren't recommended for porous surfaces like stone, marble and granite.

Neutral cure doesn't give off acid. Selleys lists its Wet Area Silicone as neutral cure and suitable for glass, brass, powder coat and stainless steel.

Our hardware is brass, finished six ways. Use a neutral-cure wet area silicone. It's the safe choice for the hardware, for natural stone and for the glass.

When can I use the shower?

Follow the tube. As an example, Selleys says of its Wet Area Silicone: "The shower can be used 24 hours after application," with a full cure in 72 hours.

Some fast silicones say you can shower sooner. If you can wait the full 24 hours, do. Silicone that gets wet before it has skinned properly can wash out or cure with gaps.

Where the silicone goes

On a typical fixed panel:

• Along the bottom of the glass where it sits on the hob or floor, on both sides.
• Up the gap between the glass and the wall.
• Into the drilled holes in the wall before you fit the plugs.

Doors aren't siliconed where they swing. They use seals instead. See do frameless screens leak?

How to get a clean bead

1. Clean first. Remove every trace of old silicone. New silicone doesn't bond to old.
2. Dry the surfaces. Silicone won't stick to wet tile.
3. Mask both sides of the joint with tape for a crisp line.
4. Cut the nozzle at 45 degrees, a little smaller than the gap.
5. Run a steady bead in one pass.
6. Tool it smooth with a silicone tool or a wet fingertip.
7. Pull the tape straight away, before it skins.

Stopping mould

Black silicone is a common complaint. One Whirlpool member said theirs "went black from mould soon after and no amount of cleaning has removed the black."

• Use a silicone labelled for wet areas with a mould inhibitor.
• Squeegee the glass and wipe the base after showers, so water isn't sitting on the silicone.
• Ventilate: run the exhaust fan or open a window.
• If mould gets into the silicone, it won't clean out. Cut it out and replace it.

How long does silicone last?

Not forever. The NSW Guide to Standards and Tolerances says silicone sealants "may require replacement after five years" as normal house maintenance. Put a reminder in your calendar.