On one sheet of 8-1/2" x 11" paper, draw the following:

• Sealant joint detail (plan) section cut through a vertical joint (drawn to scale: full size) showing 4"-thick cladding panel, sealant, backup rod, and bond breaker; and indicating the dimensions - depth and width (use 1/8" increments) - of the sealant joint.

• Sealant joint width calculations:
  • length between sealant joints (panel dimension) = 20'
  • air temperature range is from -10 to +85 degrees F.
  • movement capability of 50%
  • cladding material expands over time by 2/100 of 1% (i.e., 0.0002 x original length) due to moisture absorption
  • maximum structural movement (story drift) is 1/8"
  • expect deviations in the panel alignment (construction tolerance) of 1/8"
  • For preliminary sizing, use: W = (100/X)[eL(DT) + M] + t; where:
    • W = required width of sealant joint;
    • X = % movement capability of sealant, i.e., 50;
    • e = coefficient of expansion of building "skin" material to be sealed = 0.0000036 (see below for examples);
    • DT = annual range between extreme temperatures (assume 130 degrees F if not known; in this case, use 95 degrees F);
    • L = length of cladding panels between joints (i.e., joint spacing) = 20'
    • M = total anticipated nonthermal movement due to structural deflection, creep, moisture movement, etc.;
    • t = construction tolerance.

    Note: it is important that units are consistent. Convert all dimensions to inch units.

Coefficients of Expansion of Common Building Materials (in/in/degree F)

• Normal weight concrete 0.0000055

• Gypsum board 0.000009
• Gypsum plaster, sand 0.000007
• Glass 0.000005
• Acrylic glazing 0.000041
• Polycarbonate glazing 0.000044
• Polyethylene 0.000085
• PVC (vinyl) 0.000040