Caulking vs sealant: the difference
Contractors and manufacturers use the two words loosely. The standard printed on the tube is the part that is not loose.
A product built to ASTM C834 is a latex caulk. A product built to ASTM C920 is a joint sealant and carries a movement class with it.
Which to take
The products people call caulk are the acrylic latex ones: cheap, paintable, easy to tool, and built to ASTM C834, which sets no movement class. DAP's ALEX PLUS and ALEX FAST DRY exceed C834, and TremFlex 834 is rated to 12.5% movement.
The products people call sealant are built to ASTM C920 with a class number after it, and that number is how far the joint may move. Vulkem 116 is Class 25, DOWSIL 795 is Class 50, Dymonic 100 is Class 50 and rated +100/-50% in the field.
So the question at the counter is not which word to use. It is how much the joint moves, what it is made of, and whether it gets painted.
The caulks Cranco carries
| Product | Chemistry | Movement capability | Skin time | Paintable |
|---|
The joint sealants Cranco carries
| Product | Chemistry | Movement capability | Skin time | Paintable |
|---|---|---|---|---|
| Dymonic 100 | Polyurethane | +100/-50% (field, ASTM C719 Modified); ±50% (ASTM C719 standard) | 2 to 3 hours | Yes |
| DOWSIL 795 Silicone Building Sealant | Silicone | ±50 percent | 15 minutes | No |
| Vulkem 116 | Polyurethane | 25 % | 6 hours | Yes |
Is caulking the same as sealant?
They describe the same shelf. The word that matters on a data sheet is the standard: ASTM C834 for a latex caulk and ASTM C920 for a joint sealant, with a movement class attached.
Product pages and related comparisons
- Caulking, sealant and PU foam The full range
- Polyurethane against silicone
- ALEX FAST DRY against ALEX PLUS
- TremFlex 834 Tremco's acrylic latex caulk