Backer Rod
Use backer rod for joints deeper than 1/2" to control depth and save material.
Sealant Calculator
Enter your joint dimensions below
1
cartridge needed
0 oztotal sealant, waste included
0 ftlinear feet per tube at your joint size
0in the other tube size
0 cases12 cartridges per case, pros
Math: joint volume (length × width × depth) converted to fluid ounces, plus your waste factor, divided by tube size and rounded up. Cross-check: a 3/16" round bead works out to about 55 linear feet per 10.1 oz cartridge, which matches DAP's published coverage for Alex Plus. Rectangular joints use a little more product than a round bead, so this estimate runs slightly conservative on purpose.
Joint Design
Ideal depth-to-width ratio is 1:2 for maximum movement capability. A 1/4" wide joint wants about 1/8" of depth.
Temperature
Apply between 40°F-100°F for optimal adhesion and cure performance.
How to Measure Your Joint
Length
Measure the total linear feet of every joint you're sealing. Add each run together. Five 20-ft windows is 100 linear feet, not 20.
Width
Measure the gap across, at its widest point. If the gap changes size along the run, use the widest measurement so you do not come up short.
Depth
Measure how deep the sealant will sit, not how deep the hole is. With backer rod in place, depth is the distance from the rod to the surface.
Quick Coverage Table
Round bead, per 10.1 oz cartridge. Based on DAP published coverage data.
| Bead size | Linear feet per 10.1 oz cartridge | Linear feet per 5.5 oz tube |
|---|---|---|
| 3/16" | 55 ft | 30 ft |
| 1/4" | 31 ft | 17 ft |
| 3/8" | 14 ft | 8 ft |
| 1/2" | 8 ft | 4 ft |