I hired a high quality crew of framers for my duplex project. Two of the guys on the crew I have wanted to use in the past but they were always too busy.  They also tend to work on mansion type houses in the most expensive Calgary neighbourhoods.  This led me to assume their cost of framing would be beyond my budget. 

Once the recession hit they suddenly got a lot less busy and adjusted labour rates accordingly.  So the future owners of this project are going to be getting a very well framed house by great carpenters.  

One of the tasks they include on this project is screwing off the floors.  The floor sheets get nailed and glued as they are laid as this is the quickest and easiest way to finish a floor. Screwing the sheets on each 16 inch centred joist is a lot more work. It also takes a costly drill and expensive consumables in the form of screw clips. For this reason floor screwing has become an "upgrade" item and a cottage  industry of guys who just do floor screwing has developed, and they charge by the square foot. 

Opinions also vary as to when the floors should be screwed. Some say to do it after the house is Drywalled.  My framers disagree and do it immediately while the glue is still wet and the floor is unobstructed by walls. Right away is the easiest way to ensure every sheet gets the same amount of screws.  So not only will our buyers get a well framed house they should get one without squeeks that could form over time if the nails loosen as humidity changes (calgary is subject to many humidity swings each year).  

The first house I built for myself I screwed the floors down by hand using a cordless drill. It was a small house but it took forever and I enlisted my spouse help out with a second drill. It was really hard on the back and the knees.  If I can find that photo I will post it. Here are some shots of how it is done by pro framers.