recently I have a contractor installed hardwood floor in my house. However, after the baseboard are reinstalled back, there are huge gaps between wall and baseboards. They said it is normal and let myself do the caulking. But about 30% of the gap is pretty huge and hard to caulking. I uploaded a few pictures using a coin to measure the gap. Could anyone help and tell me if this gap is normal or not? Thank you!
If the new hardwood floor was about 3/4" thick, there may be no way to nail the baseboard trim to the 2X4 plate. That new height of the finished floor raised the trim above that 2X4 plate. You may need to locate the studs and use them as your nail surface. This is common when you add a second floor on top of another floor. You could also try nailing near the bottom of the trim, on a downward angle to try and "grab some wood" near the bottom of the trim boards. A nail gun may help in this process.
That could probably be a little tighter, but isn't terrible. (The underlying reason for a bit of a gap is that walls aren't perfectly straight or plumb.)
Where I work, caulking is done by the painter, and these gaps will caulk perfectly fine.