What’s the difference between a caulk and a sealant ?
A caulk is any low or intermediate performance compound. Typically being lower quality and having limited service lives. For example: Acrylic Latex, Butyl, Butyl Rubber, Co-polymers, putty etc. Life cycle: usually 3 – 5 years.
A sealant typically refers to a high performance compound having more expensive ingredients, little shrinkage, excellent weathering and UV resistance and providing long service life cycles from 10 – 20 years.
Purpose of Joint Sealants
1. Seal penetrations/joints between construction elements
2. Prevent ingress of water/moisture to building interior or through joints/gaps
Prevent water damage
Prevent reinforced concrete corrosion
Prevent structural steel damage
Help prevent mould development
3. Prevent hard materials or snow/ice from entering openings or joints..structural damage
4. Accommodate Movement
5. Function as Part of an Air Barrier System
6. Function as Part of a Vapor Retarding System
7. Acoustic Control
1.High-rise and low-rise commercial buildings:
Expansion joints and butt-terminations
2. Plaza decks
3. Major Chains (Tilt-up) Exteriors
Relaince Retail, Shopping malls- Inorbit, Patanjali Stores
Schools, Courts etc
5. Airport pavement runways and aprons
6. Bridge & Highway joints (DOT)
7. Commercial parking lots and flat work
8. Public Works
9. Park Decks
10. Waste & Water
Submerged environments (NSF)
11. Adhesive and bonding applications
Industrial, Residential and commercial
Typical Building Products and Materials which can be sealed
Masonry & Brick
Wood, Plywood, and Cement-Based Siding
EIFS (Exterior Insulation and Finish Systems)
Stone, Manufactured Stone, Cultured Stone
Vinyl and Aluminum Siding
Foam Plastic Panels
Metal Panels (Coated and Uncoated)
Systems include Doors, Windows, Skylight
Popular Sealants used : Acrylic ,Polysulphides, Silicones, Polyurethanes, Hybrid , MS Polymers
Popular Polyurethane Sealants : Sikaflex , Boss , Mccoy Soudalfex, Anabond, Choksi , Fosroc etc
Joint Sealants – Terminology
ASTM C 920 is the standard specification for elastomeric joint sealants. It is made up of several ASTM test methods including:
Movement capability (ASTM C 719)
Sealant hardness (ASTM C 661)
Tack free time (ASTM C 679)
Adhesion in Peel (ASTM C 794)
Sealant Hardness – ASTM C 661
Is a measure of a sealants ability to resist the penetration by a Durometer probe.
Rated on a scale from 0 – 100. The lower the number the softer the sealant. The softer the sealant the more movement it can take.
Conversely, the higher the number the harder the sealant is and the less movement it can take.
Movement Capability - ASTM C 719
Measures the cyclic movement (extension [+] and compression [-]) of a sealant. Classified with the following movement classes
Stress Relaxation – is the ability of the sealant to absorb extension without incurring additional stress on the bond line to the substrate. Sealants that recover completely and rapidly from deformation usually have less stress relaxation than those that recover slowly.
Low Modulus Sealant – Creates low stress at the sealant bond line. Usually has a higher movement capability.
Medium Modulus Sealant – Typically a general purpose sealant that can be used for the majority of elastomeric sealant applications
High Modulus Sealant – Not used for moving joints, typically used for glazing applications