NASCLA Accredited Commercial General ContractorFinishesHard
A contractor is installing a resilient sheet flooring in a large commercial space. To ensure a smooth, monolithic appearance and prevent telegraphing of subfloor imperfections, what is the most important subfloor preparation step immediately prior to adhesive application?
- AApplication of a self-leveling underlayment (SLU)
- BPriming the subfloor with a suitable primer
- CCleaning and vacuuming the entire surface
- DMoisture vapor emission testing
Show answer & explanationAnswer & explanation
Correct answer: A. Application of a self-leveling underlayment (SLU)
For resilient sheet flooring, a smooth and flat subfloor is paramount. Applying a self-leveling underlayment (SLU) effectively addresses minor imperfections, cracks, and unevenness, creating a monolithic surface that prevents telegraphing through the thin, flexible flooring material.
Why the other options are wrong
- B. Priming improves adhesive bond but does not rectify subfloor unevenness or imperfections that cause telegraphing.
- C. Cleaning is a necessary step, but it doesn't correct subfloor flatness issues that lead to telegraphing.
- D. Moisture testing is crucial, but it addresses moisture, not surface flatness for telegraphing.
Resilient Flooring Subfloor Flatness
The critical requirement for a smooth, flat subfloor, often achieved with a self-leveling underlayment, to prevent imperfections from showing through thin, flexible resilient sheet flooring.
- Prevents telegraphing
- Achieved with SLU
- Crucial for thin materials
Memory trick: For a 'smooth resilient floor', 'level' the subfloor first, so no bumps 'telegraph' through.