Construction Terms and Terminology

Interior Trim Terms

Interior Trim
Interior Trim Term Crown Moulding
Crown moulding is a decorative trim installed where
the ceiling meets the wall. Crown moulding comes in
different sizes and can be installed as one piece or
as multiple pieces with other pieces of trim.
Interior Trim Term Cove Mould
This a type of moulding that depending on the size
can be used as a crown moulding or as an inside
corner moulding. This type moulding as with other
pieces of trim can be used as a single piece of trim or
as part of multiple piece trim detail.
Interior Trim Term Shoe Mould
Shoe moulding is a small piece of trim set tight against the floor and applied to the
base. This is normally only done when the flooring is ceramic, vinyl, or wood
Interior Trim Term Window Stool
Window Stool refers to trim piece that is cut and nailed
in place in the window sill. A window stool is normally
wood and is usually cut out of a 1 x 6 piece of wood.
Interior Trim Term Base Moulding
Base is trim moulding that is installed at the bottom of
the wall where the wall meets the floor. Base will be
held up above the floor depending the floor covering.
Normally with carpet the base is installed 1/2 inch
above the floor
Interior Trim Term Mitre Joint
Mitre joint refers to the joint formed by
putting two pieces of trim together. If the trim
is cut on a 45 degree angle and applied to a
piece of trim that is cut on the opposite 45
degree angle, the joint is called a mitre joint.
Interior Trim Term Casing
Casing is a type of trim moulding used to
trim out windows and doors. This trim is
called door casing or window casing
depending on the application. Casing will
come in different sizes and profiles. Two
poplar casing are colonial and tear drop
Interior Trim Term Window Apron
Window apron is the trim piece that is installed under
the window stool. This can be a piece of base or
casing turned upside down and installed up against
the bottom of the window stool.
Category Construction Glossary
Types of wood used in interior trim:

LDF Light-Density Fibreboard
MDF Medium-Density Fibreboard
Pine and FJP Finger-Jointed Pine
Clear Spruce
Knotty Pine
Astragal a symmetrical moulding used in creating panels and horizontal
banking in cornice, wainscoting, and pilaster assemblies.

Back band used to create extra depth for casings, allowing thicker
mouldings to be butted against the casing.
Jamb: the side and top of a door or window opening.

Base block a profiled block at the base of a doorway, thicker than the
casing and the baseboard, which serves as a base for the end of the
casing to sit upon and for the baseboard to butt against.

Keystone a decorative block set in the center of a door or window
header treatment.

Base cap a moulding used in conjunction with a flat baseboard to add
height and detail.

Base corner block a small upright block used to eliminate the need for
mitering both inside and outside corners in baseboards.

Mantle a ledge usually applied above a fireplace, but also above
doorways and window openings.

Stop a small moulding used to stop a door when closed (door stop).

Flat stock stock cut flat on all sides, having no profile or decoration.

Style a vertical framing member in a frame and panel system.

Flutes hollows or grooves cut lengthwise in a moulding.

Wainscoting an assembly of mouldings used on the lower 30" to 48" of
a wall.
Medium Density Fibreboard a re-manufactured
wood product created by bonding wood fibres
together, resulting in a flexible, grain-free wood.

Built-up mouldings any combination of mouldings
used in place of a single type of moulding.

Cap a moulding used to finish the top of wainscoting,
door and window headers, and built-up moulding

Mullion a moulding to bridge the joint between two
windows set closely together.

Capital the upper-most part of a column, usually very

Panel moulding mouldings used with flat stock to
create framed panels. Sometimes used alone to
create panels on a flat surface.

Pilaster a flat vertical assembly, frequently fluted, with
a capital and base used against a wall to create a
column effect.

Chair rail a moulding applied horizontally to a wall
approximately 36" to 48" from the floor.

Rail a horizontal framing member in a frame and panel

Column an upright support with a decorative capital
and base.

Reveal the amount of door or window jamb left
exposed after installing casing.

Corner block a block used to eliminate the need for a
miter joint at the top corners of doors and windows.

Shell corner a corner block with a rounded outside

Dentil a moulding with repeated square or rectangular
blocks used as part of a built-up cornice assembly.