Specialist Sealants

About Specialist Sealants

Specialist sealants are purpose-formulated sealing compounds designed to tackle specific challenges that general-purpose sealants cannot adequately address. Unlike standard silicone or acrylic sealants, these advanced products are engineered for demanding applications including fire protection, acoustic insulation, high-temperature environments, glazing installations, and specialised building materials. Whether you're working with lead flashing, paving slabs, or brake lines, specialist sealants provide the performance characteristics required for professional-grade results.

Our range includes intumescent sealants that expand when exposed to heat to prevent fire spread, acoustic sealants that reduce sound transmission between rooms, butyl rubber sealants for waterproofing and vibration damping, and industrial-grade polyurethane formulations that withstand extreme movement and chemical exposure. From heritage restoration projects requiring patination oils to modern installations demanding C3-rated sealants for harsh environments, specialist sealants ensure compliance with building regulations whilst delivering long-lasting, reliable performance.

Leading brands such as Everbuild dominate this category with proven formulations trusted by professional tradespeople across the UK. Whether you're a plumber requiring high-temperature sealants, a builder working on fire-rated compartmentation, or a landscaper sealing block paving, having the correct specialist sealant for the job ensures regulatory compliance, reduces callbacks, and maintains professional standards.

Jargon Buster

Intumescent Sealant

A fire-resistant sealant that expands when exposed to heat, forming an insulating char layer that prevents fire and smoke spread through gaps and penetrations. Essential for maintaining fire compartmentation in compliance with Building Regulations Part B.

C3 Rating

A classification under BS EN 15651 indicating a sealant suitable for high-movement joints (±25% movement accommodation) in very low modulus applications. Ideal for demanding environments with extreme temperature variations or structural movement.

Butyl Rubber Sealant

A non-curing, permanently flexible sealant based on polyisobutylene. Excellent for waterproofing applications, bedding glazing units, and sealing metal-to-metal joints where vibration damping is required.

Polyurethane (PU) Sealant

A high-performance elastic sealant offering superior adhesion to most building materials, excellent UV resistance, and the ability to be overpainted. Commonly used in construction joints, concrete repair, and industrial applications.

Patination Oil

A specialised treatment applied to lead flashing and roofing to accelerate the natural weathering process, creating a protective patina that prevents lead carbonate staining on adjacent masonry.

Acoustic Sealant

A permanently flexible, non-setting sealant designed to seal gaps in sound-rated partitions and floors, preventing airborne sound transmission whilst maintaining the acoustic performance of the construction.

Who Uses Specialist Sealants?

• Plumbers and heating engineers requiring high-temperature sealants for flue installations and system components
• Fire protection specialists installing passive fire protection systems in commercial and residential buildings
• Glaziers and fenestration installers bedding glass units and sealing window frames to structural openings
• Roofers and leadworkers treating lead flashings and creating weatherproof seals on roofing materials
• Builders and general contractors requiring building mastic for construction joints and gap filling
• Acoustic engineers and drywall installers working on sound-rated partitions in schools, hospitals, and residential properties
• Landscapers and groundworkers sealing block paving, patios, and external surfaces against weathering and weed growth
• Automotive and vehicle technicians sealing brake lines and pneumatic systems
• Heritage restoration professionals working on listed buildings requiring specialised conservation products
• Facilities maintenance teams conducting repairs and improvements across commercial estates

How to Choose the Right Specialist Sealants

Identify the specific application: Determine whether you need fire resistance, acoustic performance, high-temperature capability, or specialised adhesion properties. Standard sealants cannot substitute for specialist formulations where building regulations or performance specifications require specific characteristics.

Consider environmental exposure: External applications require UV-resistant, weatherproof formulations capable of withstanding British weather conditions. Check whether the sealant is rated for internal, external, or both environments, and verify its performance in damp or permanently wet conditions.

Assess movement accommodation: Construction joints experience thermal expansion, structural settlement, and vibration. Select sealants with appropriate movement ratings—low modulus PU sealants typically accommodate ±25% movement, whilst butyl rubber products remain permanently flexible without curing.

Verify regulatory compliance: Fire-rated applications must use intumescent sealants tested to the required fire resistance period (typically 30, 60, or 120 minutes). Acoustic installations require sealants that won't compromise the sound reduction index of the partition system.

Check substrate compatibility: Ensure the sealant adheres effectively to your materials—some specialist sealants are formulated specifically for porous substrates, metals, plastics, or composite materials. Always conduct compatibility tests on critical or unusual substrates.

Consider curing requirements: Some applications benefit from non-curing formulations that remain permanently flexible, whilst others require sealants that cure to form a durable, overpaintable finish. Factor in curing time when planning your work schedule.

Popular Accessories

• Sealant guns and applicators including skeleton guns, cartridge guns, and professional pneumatic dispensers for consistent application
• Smoothing and finishing tools for achieving professional joints and removing excess material
• Surface preparation materials including cleaners, primers, and abrading tools to ensure proper adhesion
• Masking tape for creating clean, straight sealant lines and protecting adjacent surfaces
• Backing rods and bond breakers for controlling sealant depth and ensuring proper joint geometry
• Gun cleaning solvents to maintain applicator equipment and extend tool life
• PPE including gloves and safety glasses for safe handling of chemical products

Safety Information

Always read product safety data sheets before using specialist sealants, as formulations may contain isocyanates, solvents, or other substances requiring specific handling precautions. Work in well-ventilated areas when applying sealants, particularly solvent-based or curing products that release vapours during application and curing.

Wear appropriate PPE including chemical-resistant gloves and safety glasses to prevent skin and eye contact. Some specialist sealants may cause skin sensitisation with repeated exposure—follow COSHH guidelines and use barrier creams where recommended by manufacturers.

When working with intumescent or fire-resistant products, ensure installations comply with the manufacturer's tested and certified systems—incorrect application can compromise fire protection performance. Keep specialist sealants away from foodstuffs and ensure adequate ventilation in occupied spaces during application and curing.

Store sealants in cool, dry conditions away from direct sunlight and heat sources. Dispose of empty cartridges and contaminated materials according to local authority guidelines and environmental regulations.

Frequently Asked Questions

What's the difference between intumescent sealant and fire-rated foam?

Intumescent sealant expands when exposed to heat to form a dense char that prevents fire spread, whilst fire-rated foam provides initial gap filling but relies on intumescent coatings or wraps for fire resistance. For small penetrations and joints, intumescent sealant is typically more appropriate and easier to apply neatly. Both products must be specified according to the fire resistance period required and the size of the penetration being sealed.

Can I use standard silicone instead of acoustic sealant?

No—standard silicone cures to form a relatively rigid seal that can transmit sound vibrations, compromising the acoustic performance of sound-rated partitions. Acoustic sealants remain permanently flexible and are specifically formulated with high mass to block airborne sound transmission. Using inappropriate sealants in acoustic installations can reduce sound insulation by 5-10 decibels or more.

How long does specialist sealant last once applied?

Service life varies by product type and exposure conditions. Polyurethane sealants typically last 20+ years in external applications, butyl rubber sealants remain effective for decades due to their non-curing nature, and intumescent sealants maintain fire protection properties for the building's lifetime when properly installed. Regular inspection is recommended for critical applications such as fire protection and structural waterproofing.

Do specialist sealants require primers?

Some substrates and sealant types require primers to ensure adequate adhesion—porous surfaces like concrete often benefit from priming, whilst non-porous materials like UPVC or metal may require specialist primers. Always consult the manufacturer's technical data sheet for substrate-specific preparation requirements. Test adhesion on a small area before proceeding with large-scale application.

Can specialist sealants be painted over?

Polyurethane and some acrylic-based specialist sealants can be overpainted once fully cured, making them ideal for decorative finishes. However, silicone-based products and butyl rubber sealants generally cannot accept paint. Check product specifications before selection if overpainting is required—some intumescent sealants can be painted with compatible fire-rated paints without compromising their fire protection properties.