Introduction
Choosing the right sealant is crucial for ensuring durability, flexibility, and long-term protection for your project. Whether you're sealing windows, bathrooms, roofing, or industrial surfaces, selecting the best sealant can make all the difference. This comprehensive Sealant Buying Guide will help you navigate the different types, applications, and factors to consider before making a purchase.
What is a sealant?
A sealant is a material used to block the passage of fluids, air, or dust through surfaces, joints, or openings. It provides adhesion, flexibility, and resistance to various environmental conditions. Sealants are widely used in construction, automotive, plumbing, and DIY home improvement projects.
Types of Sealants
Understanding the different types of sealants available will help you make an informed decision:
1. Polyurethane Sealants
Polyurethane sealant is a versatile mastic that bonds and seals dissimilar materials such as metal, glass, tile, and wood. It usually requires no primer and is available in task-specific formulas like anti-mould, window and door, and multi-purpose. Ideal for sealing tiles, frames, and door sets, and for filling gaps or cracks in walls and ceilings.
Best for: Expansion joints, roofing, and flooring
Features: High-strength bonding, weather-resistant, and excellent adhesion to various surfaces
Example: Sikaflex, Gorilla PU Sealant
2. Silicone Sealants
Silicone sealant is a flexible, rubber-like adhesive used in construction, fit-out, and maintenance. It makes watertight and airtight joints in bathrooms, kitchens, and other wet areas. It also works well for glazing and many industrial jobs. The sealant cures at room temperature to an elastic finish that moves with the joint and resists moisture, temperature changes, and UV.
Best for: Bathrooms, kitchens, windows, and outdoor applications
Features: Highly flexible, waterproof, and resistant to extreme temperatures
Example: CT1, Everbuild 500, Dow Corning 785
3. Decorators Caulk (Acrylic Sealant)
Decorators caulk is a water-based acrylic sealant for filling interior cracks and gaps. Use it around skirting boards, architraves, window and door frames, and along drywall joints. It sticks to plaster, wood, PVC, and metal, skins quickly, smooths easily, and can be painted once dry. It provides a moisture-resistant seal for indoor areas and is not a replacement for waterproof silicone in constantly wet zones.
Best for: Bathrooms, kitchens, windows, and outdoor applications
Features: Highly flexible, waterproof, and resistant to extreme temperatures
Example: CT1, Everbuild 500, Dow Corning 785
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Summary
This guide helps you choose the right sealant for durability, flexibility, and long-term protection.
Polyurethane: high-strength bonding for exterior and structural jobs, ideal for expansion joints, roofing, and floors.
Silicone: long-lasting waterproof and airtight seals for bathrooms, kitchens, windows, glazing, and outdoor use.
Decorators caulk (acrylic): paintable, low-odour option for interior gaps around skirting, architraves, and plaster. Not suitable for constant water exposure.
What to consider: substrate compatibility, joint movement, water and UV exposure, temperature range, cure time, colour, and paintability.
Ready to start? Shop polyurethane, silicone, and decorators caulk now. Buy sealants online for fast UK delivery and competitive prices.