Yellow Popler can be used in construction and can be graded using the softwood rules. However, very few people are certified to grade poplar. The grade makes all the difference as to whether this can be used for structural purposes at all. Since you asked, I looked it up and poplar has been looked at for glu-lam construction and compared to Southern Yellow Pine. Based on what I saw on the web site, I would not use this un-rated beam for structural purposes. But it makes a great trim and cabinet wood.