i am going to inclose a covered patio on a building the patio is of i-beam construction. the roof has about a 30degree pitch, i dont have a problem constructing the walls. i was informed by the owner that there is to be no drilling or bolting through the steel i-beams for the top plate. the walls are to be flush with the outside of the steel, so the walls are under the i-beams my question is what is the best way to attach the top plate?