How to Install Window Stool and Apron Trim Part 2

What You'll Need
Casing Wood
Apron Wood
4d finish nails
Measuring tape
Miter Saw

A window stool might be among the last finishing touches to a home. Follow the simple steps below to finish installing your window stool and apron trim.

Step 1 – How to Install Stool

When the notches are cut, you are all set to install the window stool. Before you permanently nail the stool into place, do a test fit. You may need to fine tool the stool by shaving a bit more off or by using sandpaper. Apply glue to the window sill and face. Nail the stool into the window sill. The best nails to use are 18-gauge, otherwise known as 4d finish nails.

Step 2 – Measure and Cut Side and Head Casing

Measure the width and length of the window from the outside edge. Unlike with the window stool, you will not add any additional inches to your measurements. You will need 2 pieces of the length you measured for the length and width of the window. When cutting the casing, it is important that you get the right size as you do not want any cuts within it. Adding 2 pieces together for the desired length is not an option. Once you have the correct lengths, use a miter saw to cut your window casing.

Step 3 – Install Side and Head Casing

Put your casing pieces up against the window, and make a mark where the inside edge meets up with the head jam. You should make a square cut at the mark and repeat this on both ends of the casing. You want to apply some glue where the casing overlaps with the side jamb. Also apply glue where the edge rests on the window stool. Nail this casing into the jamb using 4d finish nails. Then nail it into the wall with 8d finish nails. If any glue has leaked out, wipe it away.

Step 4 – Measure and Cut Window Apron

The apron should be the same length as the window stool. You can hold it up against the apron as a way to measure. Where you placed marks you should use a miter saw and make square cuts. You can make the edges dressy or embellished by using a coping saw or jigsaw and then sanding the edges smooth.  You also can make a return for the ends, though this is time consuming and can be tricky.

Step 5 – Install the Apron

Apply glue to the edge of the apron that goes against the window stool.  In addition to gluing, you also want to nail it into the wall. It is best to drill pilot holes which can prevent any possible wood splitting. If any glue is visible, wipe it away.