around the beam merely moves the point of condensation. Rust can form and accumulate, weakening the beam and creating growing lumps of rust which force themselves into and under the surrounding materials with irresistible force. Even without rust problems, condensation can be a permanent nuisance, as the water drips into hidden construction or behind plaster. Whether wood or steel, the beam will be loaded and unloaded periodically by people, snow and wind loads. Its inside portion must be tied down properly to avoid cracks which open and close with the beam's flexing. Differential Vertical Shrinkage As I have mentioned numerous times in this column, it is important to avoid large differences in vertical shrinkage at various points in the house, especially as the