CT1 BT1 Sanitary Sealant & Adhesive 290ml White

BT1 sealant from CT1 is one of those products that makes you wonder why it took so long for someone to make it. Rather than applying a bonding adhesive and then a separate sanitary sealant, BT1 does both jobs in a single cartridge. It is built on CT1’s TRIBRID technology, which sits somewhere between silicone, MS polymer, and hybrid chemistry, and the result is a compound that bonds, seals, stays flexible, and resists mould across its entire service life.

It costs £7.95 a cartridge. At that price, for what it does, it is genuinely hard to argue against.

What Makes BT1 Sealant Worth Using

Most bathroom sealants are sealants. That is it. BT1 carries real adhesive strength alongside its sealing properties, which changes how you can use it on site. It has ETAG approval for bonding shower panels without mechanical fixings, which means no drilling into tiles or wall boards, no fixing holes to potentially leak later. If you have ever had to pull apart a shower enclosure that was leaking through a fixing point rather than a joint, you will understand why that is a meaningful feature rather than a marketing line.

The flexibility of the cured compound matters just as much. Joints around baths, shower trays, and basins are under constant stress. Thermal movement, daily use, slight substrate flex — a stiff sealant cracks. BT1 moves with the joint and stays intact. The anti-ageing properties in the formulation work against shrinkage and cracking over time, so the finish holds up considerably longer than a standard sanitary silicone.

Hygiene Performance

The bacteriological performance has been independently tested to ISO 22196:2011 under MOD standards. Bacteria on the cured surface is reduced by up to 99.99%. In a domestic bathroom that is a welcome feature. In a hospital, care home, or clinical facility, it moves from welcome to essential. BT1 is also formulated to resist mould and fungal growth across its service life, not just for the first few months while the surface is still fresh. The persistent black line that appears along bathroom sealant joints, usually about six months after installation, is something BT1 is specifically designed to prevent.

It is EC1 Plus certified for very low emissions, so it can be applied in enclosed spaces without needing the kind of ventilation that some solvent-based products demand. Useful in occupied buildings and tight spaces where airflow is limited.

When fully cured, BT1 can be overpainted with water-based paints, which helps where the sealed joint falls within a decorated area and a consistent finish is needed across the surface. Solvent-based paints are not compatible with the cured surface, so keep that in mind during spec.

BT1 bonds to most common building materials even when surfaces are wet, which removes one of the more frustrating constraints of standard bathroom sealants. Condensation, residual moisture, surfaces that were not dried quite thoroughly enough — BT1 handles conditions that would compromise most alternatives. Available individually or in boxes of twelve, it suits trade buyers working across multiple bathrooms or carrying stock for ongoing maintenance contracts.