You are correct the I-beam (steel) is close to W8*20 (not sure exactly I only found specs for 17 & 21 and it is inbetween those). It is contiguous and supported at four points, ends and two columns. Columns are (http://www.cardinalhomeproducts.com/buildingcolumns.html) and 7ft high, 4"...
I have a 8 x 5.5" I beam spanning 33 ft the main floor of the house. The house is two story frame construction with basement. The I beam has two supports which are steel pipe, 4" diam, wall thickness unknown. These supports rest on 6 * 3" steel plates and are adjustable in...