On 2006-12-01, Darryl wrote:

However, a 20x20 section of the floor slopes down to an unused sump
pit. How do I level the floor to compensate for this slope? Do I
first nail the 2x4s to the sloping floor (a very slight slope) and then
somehow level the osb panels, or do I make the concrete level first
before attaching the 2x4s?

For the region where the concrete slab is sloped, I suggest starting
with a thicker sleeper (e.g. a 3x4 or non-flat 2x4) and scribing the
bottom edge to the floor slope at the proper height to be in plane
with the other sleepers. Then you are level and can just attach the
osb panels.

To do the scribing, put the sleeper down on the floor, raise up and
support one end to make it level, and determine how much higher the
top of the sleeper now is than where you want it. Then set a pair of
dividers to this amount and scribe the sleeper to the floor. If you
cut the sleeper on the scribe line, then it should fit snug against
the floor and be level on the top at the proper elevation.

Cheers, Wayne