How to Install a Baseboard Over an Existing Carpeted Floor

Slide a stud finder along the wall, near the carpeted floor. Mark the center of each stud you come across. Make the marks higher than the new baseboard so you will see them clearly during installation.

Hold a piece of baseboard against the wall, with at least 1 inch extending past one of the room's outside corners. Draw a line up the back of the baseboard, using the wall as a guide. Set this piece of baseboard aside. Place another piece of baseboard against the wall on the corner's other side and draw a line up the back, following the wall.

Set the baseboard on a miter saw, positioned against the miter saw's fence the same way it will be positioned on the wall. Set the miter saw blade to a 45-degree cut. Cut the baseboards along the marks you made in Step 2.

Place the baseboard against the wall, with the mitered end in front of the outside corner. Set a level on the baseboard and adjust it either up or down. Drive 8d finishing nails through the baseboard and into the stud. Use a pair of finishing nails for each wall stud, one near the baseboard's top edge and one near the baseboard's bottom edge.

Apply a bead of wood glue along the second piece of baseboard's mitered end. Line up this end with the first piece of baseboard's end and push them together. Secure the baseboard to the wall studs with pairs of 8d finishing nails.

Measure the distance from the end of one of the pieces of baseboard to the next corner. If this corner is also an outside corner, repeat the same process with this corner as you did for the previous corner. If this corner is an inside corner, mark the distance on the back of a new baseboard and use a straight edge to draw a line along the baseboard's back.

Continue to install baseboard around the room. Use a level on each baseboard before nailing it in place to ensure the carpet is not making it sit unevenly along the wall.