Choosing the Right Sealant: Silicone vs Polyurethane vs Hybrid
A professional guide to selecting the right caulking product for bathrooms, facades, fire-rated walls, and more.
Not all caulking products are created equal. Using the wrong sealant for a job is one of the most common causes of premature failure. Here's a guide to selecting the right product for every application.
Silicone Sealants
Silicone is the go-to choice for wet areas — bathrooms, kitchens, and laundries. It offers excellent water resistance, flexibility, and mould resistance when formulated with fungicide. However, silicone doesn't accept paint and isn't suitable for all substrates. Neutral-cure silicone should always be used on natural stone to prevent staining and etching.
Polyurethane (PU) Sealants
PU sealants are the workhorse of external and facade sealing. They offer superior adhesion, high movement accommodation, and can be painted over. They're ideal for expansion joints, cladding perimeters, and anywhere that requires UV resistance and long-term durability in exposed conditions.
Hybrid Sealants
Modern hybrid sealants combine the best properties of silicone and polyurethane. They offer good adhesion to most substrates, are paintable, and provide excellent weather resistance. They're increasingly popular for both internal and external applications where versatility is needed.
Fire-Rated Sealants
For penetrations and joints in fire-rated walls and floors, specific fire-rated sealants tested to AS 1530.4 must be used. These intumescent products expand when exposed to heat, maintaining the fire resistance level (FRL) of the barrier. Installation must comply with AS 4072.1 and the tested system configuration.
Acoustic Sealants
Acoustic sealants remain permanently flexible and never fully cure, maintaining an airtight seal that prevents sound transmission through gaps in walls, ceilings, and floors. They're essential in multi-dwelling developments and commercial spaces where noise transfer ratings (STC/Rw) must be maintained.
At CaulkTech, we select and specify the right product for every joint based on substrate, exposure, movement requirements, and compliance needs. This expertise is what separates professional results from DIY attempts.