Practical Engineering: Calculating Loads on Beams and Headers

www.jlconline.com: Most builders install built-up dimension lumber headers over standard window and door openings without worrying about the loads. You just put in the same-size double 2×10 or 2×12 headers throughout the house — not only will they carry standard residential loads, but they also automatically keep the window and door heads at a uniform height. You can’t beat sawn lumber for most small window headers, but as spans and loads increase, stronger materials are a better choice. Sawn lumber limits design potential and in some cases just doesn’t work. LVL (laminated veneer lumber), glulams, and PSL (parallel strand lumbers) are all good alternatives for longer-span and heavily loaded beams.