Jonathan Ochshorn - ARCH 262 Assign#3


Jonathan Ochshorn Room 121-B, Rand Hall Department of Architecture Cornell University	contact: questions and comments back to homepage

ARCH 262: Building Technology, Materials & Methods Assign #3: Sealant joint calculations

assigned: Oct. 19, 1998
due: Oct. 26, 1998
On one sheet of 8-1/2" x 11" paper, draw an elevation of a 2-story building with brick veneer. The overall dimensions are 120' long and 30' high. Scale: 1/16" = 1'-0". Show the following: vertical and horizontal sealant joint lines glazing (25% of total surface area) column lines (evenly spaced at 20', 30', or 40') sealant joint width calculations air temperature range is from -8 to +100 degrees F. movement capability of 12.5% or 25% (your choice) brick expands over time by 2/100 of 1% (i.e., 0.0002 x original length) due to moisture absorption anticipated structural movement is negligible expect deviations in the brick alignment (construction tolerance) of 1/4" For preliminary sizing, use: W = (100/X)[eL(ÆT) + M] + t; where: W = required width of sealant joint; X = % movement capability of sealant, e.g., 12.5 or 25; e = coefficient of expansion of building "skin" material to be sealed (see below); ÆT = annual range between extreme temperatures (assume 130 degrees F if not known); L = length of "skin" material between joints (i.e., joint spacing) M = anticipated nonthermal movement due to deflection, creep, moisture movement; t = construction tolerance. sealant joint detail section (drawn full size) showing all dimensions, brick, sealant, and backup rod Coefficients of Expansion of Common Building Materials (in/in/degree F)
Wood Douglas Fir (parallel to grain) 0.0000021 Douglas Fir (perp. to grain) 0.000032 Pine (parallel to grain) 0.0000030 Pine (perp. to grain) 0.000019 Masonry Limestone 0.0000044 Granite 0.0000047 Marble 0.0000073 Brick (average) 0.0000036 Concrete Masonry Units 0.0000052 Concrete Normal weight concrete 0.0000055	Metals Steel 0.0000065 Stainless Steel (18-8) 0.0000099 Aluminum 0.0000128 Copper 0.0000093 Finishes 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

last updated: 19 Oct. 1998
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