Best Glue for Frameless Shower Screens

What is the best product to fix a frameless shower screen to a tile floor?

A silicone sealant will do this job — either a neutral cure or an acetic cure product is generally fine on a tiled floor. But the more important half of the Selleys answer is the second half: follow the shower screen supplier's or manufacturer's installation advice. A frameless panel is a large piece of toughened glass held by a small number of fixings, the manufacturer warrants it, and they are specific about how it is to be installed. Their instructions come before any general sealant advice.

In practice that usually means the panel is located and held by channel, clamps or spigots, and the silicone's job is to seal the junction and stop water tracking under the glass — not to hold the glass up. Treat the sealant as waterproofing, not as structure.

Acetic or neutral: how to decide

Silicone sealants cure by one of two chemistries, and on a plain glazed tile floor either will perform. The choice is made by what else the bead touches.

Acetic cure silicones release acetic acid as they cure — the sharp vinegar smell for the first day. Selleys No Mould is an acetic cure silicone made for humid, damp environments such as bathrooms, and it is shower ready in 1 hour after application. Its stated limitation matters here: it is not suitable for metals other than aluminium and stainless steel. If the screen's floor channel or spigots are brass, chrome-plated brass or an unknown alloy, acetic cure is the wrong choice.

Neutral cure silicones cure without releasing acid and are described as non-corrosive, so they do not attack metals during curing. Reach for a neutral cure product such as Selleys Wet Area Silicone where the bead touches metal fittings, natural or engineered stone, or a mirror edge.

The simple rule: plain glazed tile, either works; anything else in the joint, go neutral cure. Neutral cure is the lower-risk default on a frameless installation because there is almost always metal hardware in the joint.

Figures worth having before you start

Property	Selleys No Mould (acetic cure)	Selleys Wet Area Silicone (neutral cure)
Technology	Acetic cure silicone	Neutral cure silicone
Skin time	20 minutes	5–10 minutes at 25°C / 50% r.h.
Curing rate	2 mm / 24 hours	2 mm / 24 hours
Joint movement capability	±25% (ISO 9047)	—
Elongation	Approximately 400% (ASTM D412 modified)	—
Shower ready	1 hour after application	—
Full cure	At least 48 hours	72 hours before continuous water exposure
Packaging	290 mL cartridge, 100 mL tube	—

Indicative data only, not intended for the preparation of specifications.

What the cure figures mean at floor level

Cure runs at about 2 mm per 24 hours, from the outside in. A shallow perimeter bead is fully cured in a day or two. A deep fillet where the glass meets the tile — the kind that fills a wide gap in one pass — is not, and it can feel firm on the surface while remaining uncured underneath for days. Size the bead to the joint rather than over-filling it.

Shower ready and fully cured are different milestones. No Mould is waterproof and shower ready one hour after application, but the semi-cured sealant must not be touched until fully cured, which takes at least 48 hours. A bead someone leans on at hour six is a bead that has been permanently deformed.

The floor joint is the one that gets loaded. The base of a shower screen sits in standing water more often than any other joint in the room, and it takes knocks from feet and cleaning. Push the sealant into the joint rather than laying it on the surface, so it grips both faces with real depth.

How to apply it

1. Follow the screen manufacturer's installation instructions for locating and fixing the panel. Do not substitute sealant for their specified fixings.
2. If you are resealing rather than installing, remove all the old sealant first. Fresh silicone does not bond reliably to cured silicone.
3. Clean the surface thoroughly with turps and let it dry. Any soap film, body oil or cleaner residue left in the joint is what the new bead will stick to instead of the tile.
4. With No Mould, spray Selleys Rapid Mould Killer into the gap first to kill residual mould, then dry the joint completely.
5. Cut the nozzle at a 45° angle, sized to the joint. Cut the cartridge tip and fit the nozzle.
6. Place the cartridge in a caulking gun and apply with steady pressure, making sure the sealant is pushed into the joint rather than sitting on top of it.
7. Tool with a spatula dipped in detergent water within 10 minutes of application. This forces the sealant into the joint and leaves a concave face that sheds water.
8. Clean up with turps before the product skins.
9. Leave it alone. Shower ready in 1 hour with No Mould, but no touching until at least 48 hours have passed.

Limitations to check first

• No Mould is not suitable for metals other than aluminium and stainless steel. Identify the screen hardware before choosing an acetic cure product.
• No Mould is not paintable. Complete any painting seven days before sealing.
• Not suitable for permanent water immersion, and not for aquariums, food or drinking water contact.
• Wet Area Silicone is formulated for non-oily timber among its listed substrates. Oiled or waxed timber thresholds should be tested first.
• The sealant is not a structural fixing. Liquid and silicone products in the Selleys range that address structural bonding say so explicitly, and these do not.

Common questions about sealing a frameless shower screen

Should I use neutral or acetic cure?

Either is generally fine on glazed tile. Choose neutral cure if the bead touches metal fittings, stone or a mirror, since neutral cure silicones are non-corrosive.

Does the silicone hold the screen up?

No. Follow the screen manufacturer's installation advice for the fixings. The sealant seals the joint.

How soon can I use the shower?

With Selleys No Mould, one hour after application. It still needs at least 48 hours to cure fully, and must not be touched in that time.

Do I seal both sides of the glass?

The manufacturer's instructions decide this. Many frameless installations are sealed on the wet side only so that any water that does get behind the glass can drain back out rather than being trapped.

Can I seal over the old bead?

No. Remove all existing sealant before resealing — see can I apply another bead of silicone after the first dries.

How long do I have to tool the bead?

Within 10 minutes of application for No Mould, using a spatula dipped in detergent water. After that the surface skins and tooling tears it.

What if the fittings are chrome or brass?

Use a neutral cure silicone. No Mould states it is not suitable for metals other than aluminium and stainless steel.

Will the bead go mouldy?

No Mould is designed for environments where mould is normally present, but the data sheet is explicit that soap scum and dirt must be regularly cleaned off — they are the food source that lets mould establish.

How do I clean up excess silicone?

Mineral turpentine, before the product skins. Cured silicone has to be removed with Selleys Sealant Remover or by cutting and scraping.

Is there a full guide to resealing?

Yes — how to replace old silicone covers removal, mould treatment, drying and reapplication step by step.