Silicone & Sealant

CT1 is a hybrid sealant and construction adhesive that bonds and seals in one cartridge, replacing standard silicone, acrylic and many polyurethane adhesives across almost any substrate.

Harbro Electrical stocks the CT1 range at trade prices, in stock at our Peterlee trade counter and ready for UK mainland delivery. CT1 Sealant & Adhesive 290ml is available in nine colours (Clear, White, Silver, Grey, Black, Anthracite, Oak, Beige and Brown), with 6-pack and 12-pack trade quantities also in stock. Not sure whether you need CT1 itself or one of the wider range? See our full CT1 buying guide for the complete breakdown.

Alongside the original sealant, this range covers BT1 (Clear) and BT1 (White) for bathroom and sanitary work, FC1 Decorators Caulk for pre-paint joint filling, Peel Tec for stripping old paint and cured sealant, MultiSolve for surface prep and joint tooling, and Power Grab 'N' Bond for heavy-duty structural bonding.

The universal choice, and the one to reach for unless one of the cases below applies to you. One 290ml cartridge bonds and seals across virtually any substrate - metal, glass, wood, MDF, concrete, most stone and most plastics - without primers or mechanical fixings. It cures in wet conditions and underwater, won't shrink or crack over time, and can be over-painted once fully cured. Available in nine colours: Clear, White, Silver, Grey, Black, Anthracite, Oak, Beige and Brown.

A different chemistry to CT1 and BT1. FC1 Decorators Caulk is an acrylic elastomer rather than TRIBRID polymer, built for pre-paint decorating work rather than structural bonding. It fills gaps up to 25mm in a single pass without slumping or shrinking, stays permanently flexible so it won't crack at movement joints, and is paintable with water-based paints in as little as an hour. Use it for skirting, architrave, coving and window sills - not for wet areas; BT1 is the right product there.

The surface-prep and tooling product for the rest of the range. Use MultiSolve before applying CT1 or BT1 to degrease the joint faces - grease and old residue will stop either product bonding properly - and use it again straight after applying the bead; a light coat stops the fresh sealant sticking to whatever you're shaping it with. Available in a 200ml site-bag size and a 500ml size for workshop or regular use.

A few closely related C-Tec products sit outside the core CT1 range but come up on the same jobs. BW1 Waterproofing & Tanking Membrane is worth adding to a BT1 order when you're tanking a shower or wet room before tiling. FC1 Ultimate Patch and Fill handles larger fill jobs and deep gaps, where FC1 Decorators Caulk is built for finer pre-paint joints. And if you need an instant bond on porous materials rather than a flexible sealant, the Superfast Plus range is a separate fast-cure adhesive, also stocked at the trade counter. All three are in our full silicone and sealant collection.