My house is a converted bus garage 32'wx48'l. It is made of concrete/cinder blocks all the way around with 9'-10' high walls and sits on a concrete slab. The attic space is accessible through a 3x3' hole in the back wall. In the attic, beams made of 2x6's 3-abreast run the width of the house, with the ends sitting on the concrete. There are no loadbearing walls. These beams are spaced about 8' apart, and some joists run between them here and there. The rafters are 2x4s that form an angled U shaped hip roof, similar to those seen on small yard sheds. There are 2x4's running mid-rafter (about 4' high from the beam) to the beams. Whoever finished of the main floor (there is 1400 sq ft of living space) put in new joists for a ceiling of about 7-1/2' high. So there is a 2-1/2 to 3 foot gap between the beams and the ceiling joists. The roof, at the center, is only about 7-1/2' from the beams. I wanted to finish off the attic with about 17 x 38 feet of living space into a shower/toilet/sink bath over the existing bath and two bedrooms, plus a staircase. Is there a way to remove all of the beams/old joists and re-build them above the ceiling joists to create more headroom? I have had a contractor look at the attic, and he said the angle braces can be moved with the installation of kneewalls, which I still could do, but I have to be able to attach the beams and joists to the sides of the concrete--is this a possibility? Can I install a length-wise girder and put 2x6x20' joists across it? Or run girders withwise and joist between them every 8-10 feet or so? Would joist hangers work for this? I realize this is quite the intensive project, but if it's feasible, I'd love the extra rooms it would create! Thanks in advance!

Does one have to have soffit vents if the attic that is being insulated off for living space has roof vents and 1"-1 1/2" of space between the insulation and the roof sheathing. The house is old and the space behind the knee walls will be open (not insulated) as well as the peak. I live in Portland, OR so it is a pretty mild climate. Will I have enough air flow? Installing soffit vents seems like a pain. :gmorning: