NASCLA Accredited Commercial General ContractorFinishesMedium
A commercial project involves installing a large quantity of Type II vinyl wallcovering in corridors and waiting areas. The substrate is newly finished gypsum board. To ensure optimal adhesion and prevent issues like telegraphing of seams or surface irregularities, what is the MOST critical primer/sizing application step before installing the wallcovering?
- AApplying a clear acrylic sealer to 'seal' the gypsum board.
- BApplying a pigmented, quick-drying primer-sealer specifically formulated for wallcoverings.
- CApplying a mold-inhibiting primer to prevent future growth.
- DApplying a sand-textured primer for increased grip.
Show answer & explanationAnswer & explanation
Correct answer: B. Applying a pigmented, quick-drying primer-sealer specifically formulated for wallcoverings.
A pigmented, quick-drying primer-sealer designed for wallcoverings creates a uniform, non-absorbent surface, which is crucial for proper adhesion, workability, and preventing the telegraphing of seams or substrate imperfections through the wallcovering.
Why the other options are wrong
- A. A clear acrylic sealer might seal the gypsum, but a pigmented primer offers better hiding power and a consistent surface for adhesion.
- C. While important in some environments, a mold-inhibiting primer doesn't directly address adhesion, workability, or telegraphing concerns for wallcovering.
- D. A sand-textured primer is for paint to create a textured finish, not for smooth wallcovering application where it could cause dimpling or telegraphing.
Wallcovering Primer-Sealer
A specialized primer applied to a substrate before installing wallcovering, designed to seal the surface, promote adhesion, allow for repositioning, and prevent stains or imperfections from telegraphing through the wallcovering.
- Creates a uniform surface for consistent adhesive bond.
- Prevents excessive substrate absorption of adhesive.
- Often pigmented to obscure substrate color and imperfections.
Memory trick: For perfect wallcovering, a pigmented primer-sealer is the key player.