NCIDQ IDPX EXAM | INTERIOR DESIGN PROFESSIONAL EXAM
2026/2027 LATEST UPDATE | QUESTIONS AND VERIFIED ANSWERS
| GRADED A+
Advantages of Gypsum Drywall -
CORRECT|ANSWER
low install cost, quick & easy installation, fire resistance, sound control capability, easy availability,
versatility, ease of finishing & decorating, ease of installation of doors/other openings
Gypsum Drywall Edges -
CORRECT|ANSWER
Tapered: Most common; tapered on face side along the long dimension of the panel & square edges
at the end; allows for application of reinforcing tape & joint compound without causing bulges at
joints
Square: used where appearance is NOT a factor, for basic layers of 2-layer applications & for veneer
plaster work
Levels of Gypsum Drywall -
CORRECT|ANSWER
1: plenums above ceilings & other areas not normally open to view (tape embedded in joint
compound w/ surface free of excess compound
2. water resistant backing board (all joints & angles have tape embedded in joint & one separate
coat of compound
3. heavy or medium textured finishes/heavy-grade wallcovering ( 2 coats of compound)
4. Light textured or wallcoverings & where economy is concerned (3 layers) 5. all paints, severe
lighting conditions (4 layers)
Studs are spaced how far apart? -
CORRECT|ANSWER
residential: 16" O.C.
commercial: 24" O.C.
Slip Joint -
,CORRECT|ANSWER
prevent wall from being damaged if the structural floor deflects
Plaster Construction -
CORRECT|ANSWER
1. Scratch Coat
2. Brown Coat (level surface)
3. Finish Coat (Leveling & desired texture)
*Add Trim
Masonry Block Dimensions -
CORRECT|ANSWER
8"x8"x16" (-3/8" for mortar joints)
Demountable Partitions -
CORRECT|ANSWER
Consists of a system of individual components that can be quickly assembled, disassembled &
reused with nearly total salvageability
consists of floor runners, ceiling runners, stud sections with clips to hold panels, & prefinished gyp.
wallboard panels
uses aluminum for framing
Definition: Hinges -
CORRECT|ANSWER
Consist of 2 leaves with an odd number of knuckles on one leaf and an even number of knuckles on
the other
knuckles are attached with a pin
knuckle + pin = barrel (finished with tip)
,Types of Hinge Tips -
CORRECT|ANSWER
-flat button (most common; typical)
-hospital
-oval head (typical)
-steeple
-flush
Butt Hinge -
CORRECT|ANSWER
MOST COMMON; has both leaves fully mortised into the frame and the edge of the door so the
hinge is flush with the surface of the frame and door
raised barrel hinge -
CORRECT|ANSWER
used when there is not room for the barrel to extend past the door trim; OFFSET to allow one leaf to
be mortised into the frame (kind of has an L shape on each side)
swing clear hinges -
CORRECT|ANSWER
has a special shape that allows the door to swing 90 degrees or 95 degrees so the full opening of the
doorway is available
definition: latches & locksets -
CORRECT|ANSWER
device to operate a door, hold in position & lock it
latchset -
CORRECT|ANSWER
ONLY holds door in place; NO lock (i.e. restroom partitions)
, lockset -
CORRECT|ANSWER special mechanism that allows the door to be locked with a
KEY or THUMBTURN
mortise lockset -
CORRECT|ANSWER
installed in rectangular area cut out of door; more SECURE than cylindrical and offers wider variety
of locking options
cylindrical -
CORRECT|ANSWER
most common; simple to install in holes drilled into door, relatively inexpensive, most common in
residential (like doors in home bedroom)
pre-assembled -
CORRECT|ANSWER
rectangular box that fits within a notch cut in the edge of the door; easier to install than mortise;
door knob OR lever can be used
center hung pivot -
CORRECT|ANSWER
allow door to swing in either direction & is completely concealed
pivots CANNOT be used with a door stop (instead use a flexible strip of wool pile or synthetic
stripping can be rabbeted into the edge of the door) on the same side of the door with both jambs
because it makes it difficult to seal the door against sound or light transmission on the hinge and
strike sides
closers -
CORRECT|ANSWER
automatically return a door to its closed position after it is opened
2026/2027 LATEST UPDATE | QUESTIONS AND VERIFIED ANSWERS
| GRADED A+
Advantages of Gypsum Drywall -
CORRECT|ANSWER
low install cost, quick & easy installation, fire resistance, sound control capability, easy availability,
versatility, ease of finishing & decorating, ease of installation of doors/other openings
Gypsum Drywall Edges -
CORRECT|ANSWER
Tapered: Most common; tapered on face side along the long dimension of the panel & square edges
at the end; allows for application of reinforcing tape & joint compound without causing bulges at
joints
Square: used where appearance is NOT a factor, for basic layers of 2-layer applications & for veneer
plaster work
Levels of Gypsum Drywall -
CORRECT|ANSWER
1: plenums above ceilings & other areas not normally open to view (tape embedded in joint
compound w/ surface free of excess compound
2. water resistant backing board (all joints & angles have tape embedded in joint & one separate
coat of compound
3. heavy or medium textured finishes/heavy-grade wallcovering ( 2 coats of compound)
4. Light textured or wallcoverings & where economy is concerned (3 layers) 5. all paints, severe
lighting conditions (4 layers)
Studs are spaced how far apart? -
CORRECT|ANSWER
residential: 16" O.C.
commercial: 24" O.C.
Slip Joint -
,CORRECT|ANSWER
prevent wall from being damaged if the structural floor deflects
Plaster Construction -
CORRECT|ANSWER
1. Scratch Coat
2. Brown Coat (level surface)
3. Finish Coat (Leveling & desired texture)
*Add Trim
Masonry Block Dimensions -
CORRECT|ANSWER
8"x8"x16" (-3/8" for mortar joints)
Demountable Partitions -
CORRECT|ANSWER
Consists of a system of individual components that can be quickly assembled, disassembled &
reused with nearly total salvageability
consists of floor runners, ceiling runners, stud sections with clips to hold panels, & prefinished gyp.
wallboard panels
uses aluminum for framing
Definition: Hinges -
CORRECT|ANSWER
Consist of 2 leaves with an odd number of knuckles on one leaf and an even number of knuckles on
the other
knuckles are attached with a pin
knuckle + pin = barrel (finished with tip)
,Types of Hinge Tips -
CORRECT|ANSWER
-flat button (most common; typical)
-hospital
-oval head (typical)
-steeple
-flush
Butt Hinge -
CORRECT|ANSWER
MOST COMMON; has both leaves fully mortised into the frame and the edge of the door so the
hinge is flush with the surface of the frame and door
raised barrel hinge -
CORRECT|ANSWER
used when there is not room for the barrel to extend past the door trim; OFFSET to allow one leaf to
be mortised into the frame (kind of has an L shape on each side)
swing clear hinges -
CORRECT|ANSWER
has a special shape that allows the door to swing 90 degrees or 95 degrees so the full opening of the
doorway is available
definition: latches & locksets -
CORRECT|ANSWER
device to operate a door, hold in position & lock it
latchset -
CORRECT|ANSWER
ONLY holds door in place; NO lock (i.e. restroom partitions)
, lockset -
CORRECT|ANSWER special mechanism that allows the door to be locked with a
KEY or THUMBTURN
mortise lockset -
CORRECT|ANSWER
installed in rectangular area cut out of door; more SECURE than cylindrical and offers wider variety
of locking options
cylindrical -
CORRECT|ANSWER
most common; simple to install in holes drilled into door, relatively inexpensive, most common in
residential (like doors in home bedroom)
pre-assembled -
CORRECT|ANSWER
rectangular box that fits within a notch cut in the edge of the door; easier to install than mortise;
door knob OR lever can be used
center hung pivot -
CORRECT|ANSWER
allow door to swing in either direction & is completely concealed
pivots CANNOT be used with a door stop (instead use a flexible strip of wool pile or synthetic
stripping can be rabbeted into the edge of the door) on the same side of the door with both jambs
because it makes it difficult to seal the door against sound or light transmission on the hinge and
strike sides
closers -
CORRECT|ANSWER
automatically return a door to its closed position after it is opened
