CFI Carpet Installation Techniques 4 — Questions and Answers
Question 1: A customer reports that new carpet installation has visible 'shading' or 'pooling' — light and dark patches that change with viewing angle. What is the cause?
- Defective dye lot in the carpet
- Normal pile reversal caused by foot traffic and vacuum direction (Correct answer)
- Improper seaming technique
- Under-stretching of the carpet
Correct answer: Normal pile reversal caused by foot traffic and vacuum direction
Shading or pooling is caused by pile reversal where carpet fibers bend in different directions under foot traffic, changing how light reflects — it is a characteristic of the carpet, not an installation defect.
Question 2: Before installing carpet over a concrete subfloor, the installer should perform a moisture test. What is the maximum acceptable relative humidity reading using an in-situ probe?
- 65%
- 75% (Correct answer)
- 85%
- 95%
Correct answer: 75%
ASTM F2170 specifies a maximum of 75% relative humidity in concrete for most adhesive flooring installations, including glue-down carpet.
Question 3: What is the primary reason carpet must be acclimated to the job site before installation?
- To allow the adhesive to pre-cure
- To let the carpet adjust to the room's temperature and humidity, preventing buckling or shrinkage after installation (Correct answer)
- To make the carpet easier to cut
- To allow off-gassing of manufacturing chemicals
Correct answer: To let the carpet adjust to the room's temperature and humidity, preventing buckling or shrinkage after installation
Carpet fibers expand and contract with temperature and humidity, so acclimation prevents post-installation buckling or gaps caused by dimensional changes.
Question 4: When power stretching a room, what is the recommended stretching sequence?
- Start in the center and work outward in all four directions
- Stretch lengthwise first, then widthwise, working in a pyramid pattern from one corner (Correct answer)
- Stretch both directions simultaneously from the center
- Start at the doorway and stretch toward all walls
Correct answer: Stretch lengthwise first, then widthwise, working in a pyramid pattern from one corner
The correct sequence is to anchor on two walls, stretch lengthwise in a pyramid pattern, hook the far wall, then stretch widthwise to eliminate any remaining wrinkles.
Question 5: What is a 'transition strip' used for in carpet installation?
- To join two pieces of carpet in the middle of a room
- To provide a finished edge where carpet meets a different flooring surface or doorway (Correct answer)
- To cover the tackless strip along the perimeter
- To reinforce seams under heavy furniture
Correct answer: To provide a finished edge where carpet meets a different flooring surface or doorway
Transition strips (T-moldings, reducers, or carpet bars) provide a safe, finished edge where carpet meets tile, hardwood, or other flooring at doorways and changes in floor level.
Question 6: A berber carpet installation requires pattern matching at a seam. The pattern repeat is 18 inches. How much extra material must be ordered per seam?
- No extra material needed
- 9 inches
- 18 inches (one full repeat) (Correct answer)
- 36 inches (two full repeats)
Correct answer: 18 inches (one full repeat)
For each seam requiring a pattern match, you must allow one full pattern repeat of extra material to ensure the patterns can be aligned.
Question 7: Which installation method is most appropriate for a commercial carpet tile application?
- Stretch-in over pad
- Perimeter-only double-faced tape
- Full-spread pressure-sensitive adhesive (Correct answer)
- Loose-lay with no adhesive
Correct answer: Full-spread pressure-sensitive adhesive
Commercial carpet tile typically requires full-spread pressure-sensitive adhesive to ensure dimensional stability and prevent tile movement under heavy foot traffic.
CFI Carpet Installation Techniques 4
A customer reports that new carpet installation has visible 'shading' or 'pooling' — light and dark patches that change with viewing angle.
What is the cause?