Start by putting the baseboard end of the flooring under the first baseboard at an angle.
How to install wood floor under existing baseboard.
I m kind of astounded that your hardwood installer would put the new hardwood right up against the existing baseboards that is a total no no for hardwood installation.
Use baseboard nails or brads no longer than 18 inches apart for 3 4 inch thick molding.
Then slide the long edge of the flooring under the other baseboard straightening the flooring piece into place.
Once you have gathered all the tools here are the steps to installing your new baseboard molding.
Fill any nail holes and apply any touch up as needed.
Use 11 4 to 11 2 in long enough to penetrate the molding the drywall and drive at least 1 2 inch into the wall s base plate.
Nail it to the baseboard not to the floor or subfloor.
Wood expands and contracts with the seasons and needs an expansion gap around the perimeter so it doesn t cause buckling in the floor during an expansion time of year.
Leave a 1 4 inch or larger gap between the existing baseboard and the new hardwood flooring you are installing.
This gap is needed to give the hardwood room to move with changing humidity.
Keep the lower edge of the baseboard even with the top of the floor and nail the baseboard into the wall.
Install the base shoe quarter round molding over the expansion gap created by your new hardwood flooring.
Set the quarter round shoe moulding on a piece of paper to keep it just a hair above the floor.
Nail threshold or transition strips in place where the edge of the floor is exposed.