my problem is an odd ball, at least in my experience. I have recently purchased a 1920's built home.
the problem is that the dining room floor shakes when you walk across it. The main support beam spans the room on one third of the width. the beam is well supported and fully loaded along it's entire length. this is the only room that does this. the previous owners had tied the joists together with a ten foot piece of paired 2x6 lagged into the individual joists. any help will be very much appreciated