TOPIC: Gap between the wall and vanity during the cold months???

Joe, all I really have is theory, I'm in no way an engineer. My theory is that when the truss uplifts, it would pull the exterior wall inward, and when it relaxes to its original position, it pushes the wall back outwards. I suppose an engineered truss wouldn't be as susceptible as stick built rafters. maybe I'm bass ackwards? 

Mike, Truss uplift doesn't affect exterior walls. Trusses are load bearing on exterior walls only and non load bearing on interior walls and even not fastened to interior walls due to the truss uplift. Truss uplift brackets sometimes are used around here, but trusses are never fastened to interior wall top plates. Truss uplift is basically only the bowing up and down of the bottom chord of trusses thru the interior of the home. The bottom chord is the only one burried in the blown insulation. During the winter of course the bottom chord is kept warmer versus the exposed other chords of the trusses.
Mike, Your theory of Truss uplift pulling exterior walls inward and then back out would sure cause a problem for masonry on those exterior walls. This is not a possibility of truss uplift. There is no possible consiquences to exterior walls from truss uplift - Only to interior walls and ceilings at those areas of the bottom chords of trusses.

Hi Joe,

I know what truss up lift is.  I said something like truss up lift where the lumber is being affected by the temperature difference.  Maybe because the lumber is green (still drying).  Not sure.  It seems to have something to do with the temp change. 

The gap was along the East wall (right side of the vanity).  The back is along the North wall. 

Thank you for your thoughts. 
Have a great night!

Mike K, didn't mean to ruffel your feathers. I was voicing my opinion on this open forum where you posted a situation. I'm glad you know what truss uplift is. But it is nothing comparable to green lumber still drying.
In new home construction, at least around here, lumber used is required to have a moisture content of less than 19 percent, so there is no green lumber in construction.