Curtain Wall Sealant Calculator

Perimeter sealant and weep system from joint design.

Total joint length (m)

Substrate length (mm)

Temperature range (°C)

Substrate (1-3)

Sealant class (1-3)

Construction tolerance (mm)

Tab to move between fields

Joint width (mm)

Joint depth (mm)

Thermal movement (mm)2.77

Total movement (mm)5.77

Backer rod dia. (mm)8

Sealant per metre (mL)36

Total sealant (L)7.2

310 mL cartridges24

600 mL sausages12

Application time (hrs)0.8

Sealant NameSilicone (±50%)

Backer Rod M210

How to Use This Calculator

Enter the total curtain wall area and the number of horizontal and vertical joints.
Set joint width and depth in millimeters.
Input the sealant coverage rate and cost per unit.
Review total sealant volume needed and estimated material cost.
Add 10-15% waste factor to the order quantity for field conditions and overlaps.

How the result changes with Substrate length (mm)

Total joint length (m): Total linear metres of sealant joints on the curtain wall.
Substrate length (mm): Length of the panel or substrate along the joint direction. Drives thermal movement.
Temperature range (°C): Total temperature swing the joint will experience (e.g., -20 to +60°C = 80°C).
Substrate (1-3): 1 = Aluminum (CTE 23.1), 2 = Steel (CTE 12.0), 3 = Glass (CTE 9.0) — all ×10⁻⁶/°C.
Sealant class (1-3): 1 = Silicone (±50%), 2 = Polyurethane (±25%), 3 = Butyl/Acrylic (±12.5%).
Construction tolerance (mm): Expected construction tolerance / installation variance in mm.

Thermal movement (mm): Calculated thermal expansion/contraction of the substrate.
Total movement (mm): Thermal movement plus construction tolerance.
Joint width (mm): Required sealant joint width to accommodate all movement.
Joint depth (mm): Sealant contact depth (width:depth ratio ~2:1).
Backer rod dia. (mm): Recommended closed-cell backer rod diameter (~125% of joint width).
Sealant per metre (mL): Sealant volume required per linear metre of joint.
Total sealant (L): Total sealant volume for all joints.
310 mL cartridges: Number of standard 310 mL cartridges needed.
600 mL sausages: Number of 600 mL sausage packs needed.
Application time (hrs): Estimated labour hours for sealant application at ~4 m/min.

Identify Input Parameters
4 parameters
Total joint length (m) = 200, Substrate length (mm) = 1500, Temperature range (°C) = 80, Substrate (1-3) = 1 = 6 input(s) provided
Calculate Joint width
Joint width = max(6, ceil(minJointWidth))
6 = 6
Calculate Joint depth
Joint depth = max(6, min(designJointWidth, round(designJointWidth / 2)))
6 = 6
Calculate Thermal movement
Thermal movement = cte * substrateLength * tempRange
2.77 = 2.77
Calculate Total movement
Total movement = thermalMovement + constructionTol
5.77 = 5.77