Flitch Beams

Two types of nailed multi-member lumber flitch beams, with 16-gage steel flitch plates between the vertical laminae, appear to have considerable potential especially in the manufacture of components for mass-produced houses and other buildings. The regular flitch beams, with flat steel flitch plates on both sides of the center member of three lumber members, were from 28 percent to 48 percent more effective than similar vertically laminated beams without flitch plates. The modified flitch beams, with a U-shaped steel flitch plate encasing the top and the two sides of the center lumber member, were from 21 percent to 52 percent more effective than similar vertically laminated beams without flitch plates. Flitch beams assembled with nontreated and creosote-pressure treated lumber appear to perform in a similar manner, except that the ultimate load supported by the treated-lumber beams may be as much as one-fifth lower according to the limited test data at hand. Such lumber deficiencies as knots, cross- grain, and shakes at highly stressed locations can influence the performance of vertically laminated beams as well as flitch beams more than such design improvements as the incorporation of steel flitch plates between the lumber laminations.

You must be logged in to download any documents. Please login (login accounts are free) or learn how to Become a Member