Last week Morgan finally had a bit of time to fill this crazy hole in our living room floor. Once a vent to a heating system from before our time, it was for us a grate with a big dust-bunny and Lego collection vault beneath it. After demolition, it became a huge freaking hole to the outside, covered by a thin mat. 

Once we set the house down again, the new floor joists pushed the grate up so that every time we stepped on it it would make a huge thumping noise and give us a little bumpy ride. Annoying, but not dangerous, and not a priority. 

Finally, while the floor guys were working, the magic combination of time and available materials gelled, and we no longer have that noisy, cold-air channeling amusement ride in our living room floor.