Things You'll Need

Instructions

1

Hold the window box up to the wall below your window and mark the bottom of the wall. This is where the bottom of your L brackets should line up.
2

Drill holes in the wall where you want to attach the angle brackets to support your window box. Remember that the mark you made in Step One indicates the location of the bottom of the L brackets.
3

Tap the anchors into the holes with a hammer. Do not hit them too hard--they just require a light tap.
4

Attach the anchors to the wall by drilling two inch lag screws into the anchored holes. Tighten them snugly with a socket wrench.
5

Secure the window box to the L bracket by setting it on the brackets. Drill lag screws underneath the window box through the holes in the L bracket.