Silicone Sealant

About Silicone Sealant

Silicone sealant is an essential product for both professional tradespeople and DIY enthusiasts, offering versatile sealing and bonding solutions across countless applications. Whether you're fitting a new bathroom suite, weatherproofing windows, or sealing joints in construction work, the right silicone sealant provides a flexible, waterproof barrier that stands the test of time. At TooledUp.com, we stock a comprehensive range of silicone sealants from trusted manufacturers including Everbuild, Dowsil, Evostik, and UniBond, ensuring you have access to specialist formulations for every task.

Our silicone sealant range includes acetoxy cure (general purpose) and neutral cure options, each designed for specific applications. From bathroom and sanitary sealants with anti-fungal properties to food-grade formulations for commercial kitchens, weatherproof outdoor variants, and even mirror adhesives, there's a specialised solution for every sealing challenge. Many of our products come in standard 310ml cartridges compatible with skeleton guns and mastic applicators, making application straightforward on site or at home.

Modern silicone technology has evolved significantly, with hybrid sealant adhesives now bridging the gap between traditional sealants and construction adhesives. These advanced formulations offer exceptional adhesion, flexibility, and durability whilst remaining paintable and low-odour – ideal for occupied spaces where traditional acetoxy sealants might prove problematic.

Jargon Buster

• Acetoxy Cure: A traditional curing method that releases acetic acid (vinegar smell) as the sealant cures. Ideal for general purpose applications but not suitable for metals, mirrors, or natural stone as it can cause corrosion or staining.
• Neutral Cure: A low-odour curing system that doesn't release corrosive substances, making it safe for use on sensitive materials including mirrors, metals, marble, and granite. Generally more expensive than acetoxy varieties but offers greater versatility.
• Movement Accommodation Factor (MAF): Expressed as a percentage, this indicates how much joint movement a cured sealant can tolerate. Quality silicones typically offer 25-50% movement accommodation, essential for joints subject to expansion and contraction.
• Anti-Fungal/Bacteria Resistant: Sealants formulated with additives that prevent mould and bacteria growth in damp environments, particularly important for bathroom and kitchen applications where hygiene is paramount.
• Hybrid Sealant Adhesive: Advanced polymer formulations combining the flexibility of sealants with the bonding strength of adhesives. Often based on SMP (Silyl Modified Polymer) technology, these can be painted over and are low-odour.
• Tooling Time: The working window after application during which you can smooth and finish the sealant bead before a skin forms on the surface, typically 5-15 minutes depending on temperature and humidity.

Who Uses Silicone Sealant?

Silicone sealant is an indispensable material across numerous trades and applications:

• Plumbers: For sealing baths, showers, sinks, and sanitary ware with water-resistant, anti-fungal formulations
• Bathroom Fitters: Installing wet rooms, shower enclosures, and sanitary fixtures requiring bacteria-resistant sealing
• Window Fitters and Glaziers: Weather-sealing window frames, double glazing units, and curtain walling systems
• General Builders: Sealing expansion joints, weatherproofing external applications, and general construction sealing work
• Kitchen Fitters: Sealing worktop joins, splashbacks, and appliances with food-safe or waterproof sealants
• Maintenance Engineers: Repairs, resealing, and weatherproofing across commercial and industrial facilities
• Shopfitters: Installing mirrors, glass panels, and sealing retail fixtures
• DIY Enthusiasts: Home improvement projects including bathroom refurbishment, window maintenance, and general household repairs
• Facilities Managers: Ongoing building maintenance and weatherproofing programmes

How to Choose the Right Silicone Sealant

Selecting the appropriate silicone sealant ensures lasting results and prevents common failures. Consider these key factors:

Application Environment: Bathroom and kitchen areas require anti-fungal, bacteria-resistant formulations to prevent mould growth in damp conditions. External applications need weatherproof sealants with excellent UV resistance. Food preparation areas demand food-grade, NSF-certified products.

Substrate Compatibility: Acetoxy cure sealants work brilliantly on glass, ceramics, and most plastics but corrode metals and stain natural stone. For mirrors, metals, marble, granite, or sensitive surfaces, always specify neutral cure silicone to avoid damage and discolouration.

Movement and Flexibility: Joints subject to thermal expansion, structural movement, or vibration require high-modulus silicones with excellent movement accommodation factors. Construction and expansion joints particularly benefit from flexible, high-performance formulations.

Colour Matching: Most ranges offer white, clear (transparent), brown, black, and various standard colours. For professional finishes, match sealant colour to tiles, sanitary ware, or surrounding materials.

Working Conditions: Low-modulus sealants offer easier application and tooling, ideal for detailed work. Quick-cure formulations reduce waiting times on fast-turnaround projects, whilst standard cure times allow more working time for complex applications.

Professional vs DIY: Trade-grade products from Dowsil and Everbuild's professional ranges offer superior performance and durability for demanding applications, whilst general purpose and easy-squeeze variants provide excellent value for occasional domestic use.

Popular Accessories

• Skeleton Guns and Mastic Applicators: Essential for dispensing 310ml cartridges with control and precision
• Silicone Smoothing Tools and Finishing Tools: Create professional, smooth beads and neat joints
• Sealant Remover Tools: Specialised scrapers and blades for removing old sealant before reapplication
• Chemical Sealant Removers: Dissolve aged silicone without damaging substrates
• Finishing Solution/Smoothing Fluid: Prevents sealant sticking to tools during finishing for perfect results
• Backing Rod/Backer Rod: Foam inserts that control sealant depth in wide joints and improve adhesion
• Masking Tape: Create straight, professional edges and protect adjacent surfaces during application
• Surface Cleaners: Ensure optimal adhesion by removing grease, dust, and contaminants before sealing

Safety Information

When working with silicone sealants, observe these important safety guidelines to comply with HSE and COSHH regulations:

Ventilation: Always work in well-ventilated areas, particularly when using acetoxy cure sealants which release acetic acid vapours during curing. Open windows and doors or use mechanical ventilation in confined spaces to prevent vapour accumulation.

Skin Protection: Wear appropriate gloves when handling uncured sealant. Whilst most modern formulations have low skin sensitisation potential, prolonged contact should be avoided. Wash hands thoroughly after use and before eating or drinking.

Eye Protection: Safety glasses or goggles are recommended, especially when working overhead or cutting cartridge nozzles, to prevent accidental contact with eyes.

Storage: Keep cartridges in cool, dry conditions away from direct sunlight and sources of ignition. Store upright to prevent leakage. Check expiry dates as aged sealant may not cure properly or achieve full performance.

Disposal: Empty cartridges can typically be disposed of with general waste, but check local authority guidelines. Never dispose of uncured sealant down drains.

Frequently Asked Questions

What's the difference between acetoxy and neutral cure silicone?
Acetoxy cure silicone releases acetic acid (vinegar smell) as it cures and is the most economical general-purpose option, ideal for glass, ceramics, and most plastics. However, it corrodes metals and can stain natural stone. Neutral cure silicone doesn't release corrosive substances, making it safe for mirrors, metals, marble, and other sensitive materials. It's low-odour and more versatile but typically costs more.

How long does silicone sealant take to cure?
Most silicone sealants form a surface skin within 10-30 minutes, depending on temperature and humidity. However, full cure typically takes 24-48 hours. Thicker applications cure from the outside in, so deep beads may take longer. Avoid disturbing or exposing to water until fully cured for best results.

Can I apply silicone sealant over old sealant?
No, it's not recommended. New silicone rarely adheres well to old silicone, leading to premature failure. Always remove old sealant completely using a sealant remover tool or chemical stripper, clean the joint thoroughly with appropriate cleaner, and ensure surfaces are completely dry before applying fresh sealant.

Why does bathroom sealant go black or mouldy?
Standard sealants without anti-fungal additives can harbour mould and mildew in damp bathroom conditions. Always use bathroom-specific silicone with anti-fungal or bacteria-resistant properties. Products like Dowsil 785+ and Everbuild 500 Bath and Sanitary range are specifically formulated to resist mould growth in wet environments. Good ventilation also helps prevent mould development.

What size bead should I apply?
For most applications, a 5-8mm bead provides adequate sealing whilst allowing proper adhesion to both surfaces. Wider joints may require backing rod to control depth and ensure proper sealant profile. The ideal joint configuration is typically 2:1 width to depth ratio. Avoid filling very deep joints completely with sealant as this prevents proper curing and flexibility.