Adhesive & Underlayment Selection Flashcards
7 cards from real CFI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Adhesive & Underlayment Selection flashcards as text
When applying adhesive in a large area, an installer notices it is 'stringing' excessively. What does this indicate?
Answer: The adhesive has reached peak grab and flooring should be laid immediately
Excessive stringing (long threads when the trowel is lifted) indicates the adhesive has developed high grab and is approaching the end of its open time, signaling the installer to place flooring promptly.
What is the minimum compressive strength typically required for underlayment panels used under ceramic tile in residential applications?
Answer: 3,000 psi
Underlayment panels used under ceramic tile in residential settings should have a minimum compressive strength of approximately 3,000 psi to prevent deflection under load that would crack tile and grout.
A customer requests a floating engineered hardwood installation over existing 3/4" hardwood. What underlayment consideration is most important?
Answer: Verify total finished floor height does not exceed clearances at doors and transitions
Adding both new flooring and underlayment over existing hardwood increases overall floor height, which must be checked against door clearances, transitions, and appliance spaces.
Which adhesive system is specifically engineered for installing cork flooring tiles?
Answer: Water-based contact adhesive formulated for cork
Water-based contact adhesives formulated for cork provide the necessary bond to the open-cell cork surface without damaging it or releasing harmful solvents into the porous material.
When selecting underlayment for a luxury vinyl plank (LVP) floor, what property should the installer prioritize?
Answer: Flatness and firmness to maintain the integrity of locking joints
LVP click-lock joints require a firm, flat underlayment because excessive compression or unevenness causes the joints to open, squeak, or fail prematurely.
A job site has an ambient temperature of 55°F. How does this affect adhesive performance?
Answer: Cold temperatures slow adhesive cure and can extend open time unpredictably
Cold temperatures slow the chemical or evaporative curing process of most flooring adhesives, extending open time and delaying the achievement of full bond strength.
What does the term 'wet lay' installation mean when referring to adhesive application?
Answer: Applying adhesive and immediately placing the flooring before any open time
Wet lay means placing flooring immediately into fresh, wet adhesive without waiting for any open time, which is required by certain flooring types or specific adhesive systems.